MAJOR APOLOGY: In the video I erroneously said during the development of the CVCC Honda was developing it's first 4-stroke engine. That is wrong (as many of you pointed out). I script/outline videos and during my research on this I obviously mis-typed something and didn't catch it in editing.
They actually built a Formula 1 race engine in the mid 60's and probably previously mentioned came out in the US in the Civic the 1200 ALL Aluminum engine.(The CVCC's had a cast Iron Block) a MUCH better engine.
Everyone makes a mistake. I don’t see how you don’t miss more. Your video was still really interesting and informative. I worked in the motorcycle division for over 20 years, HONDA history is sort of my “thing”.
@@ronstucker3550 their RA273 was designed by the legendary Shoichiro Irimajiri (lead designer and engineer on the iconic RC166 and HONDA CBX). Read the story of the RC166 for some fascinating insight into how far ahead HONDA was in engine technology. HONDA even built their own gearboxes, probably because they had extensive engineering experience from their motorcycle division. It needs to be noted that much of the FI technology originated from the motorcycle division. HONDA also built the RC116 which holds the record for the highest power output for a N/A engine. The RC116 produced 321.5 horsepower per liter. It was a 49.77cc twin that produced 16 horsepower at 21,500 RPM. This was in 1966! Even Modern MotoGP engines don’t even come close to this output per liter.
@@mlynch001 Knowing by working on these early Honda engines From the late 60's 600's to the 1800's mid 80's engines and all in between.( I owned 2 1st gen 1981 Accords ) both Sticks They were one of the best most reliable cars I ever owned. Also rode bikes built in Japan from my early teens to late 20's (Harley's after that) I knew all the history of their F-1 engine program back in the 60's. In late 80+ CVCC's with the 4 exaust ports instead if the (2 port early 80- 75 heads) became the most reliable. Only problem was those Damn carbs.
This may interest you: there was large unintended engineering mistake made by the big three as they entered the smog era in the early 1970's. One of the ways American engines changed as you mentioned was to reduce the compression. That in itself was not a bad idea - but the way most American car companies did that was to slightly drop the top height of the piston. This dramatic increase in the quench height was a disaster for power and fuel mileage, and for drivability and emissions. It is much better understood now how important it is to have a tighter piston to cylinder head measurement, especially on wedge shaped combustion chambers. A closer quench height reduces emissions, while increasing power and fuel mileage. There is more to it than my simple explanation, but the science of what happens in the combustion chamber was still an elusive topic in the 1970's.
@@MisterMikeTexas You are misunderstanding what quench is: on a wedge shaped combustion chamber the valves are typically on one side, and then there is a flat portion on the other side. Quench is the distance from the flat part of the cylinder head to the top of the piston. You can actually have a low compression ratio and a tight quench all at the same time. The compression ratio is determined by the size of the combustion chamber in relation to the volume of the cylinder. Quench has no bearing on needing premium or regular fuel. Quench does affect mixture motion - tight quench OHV engines burn cleaner and more powerfully. What many of the big 3 engineers did to reduce the compression ration was to change the piston pin height by .020" to .050". This was also the reason why many of these engines had horrible dieseling problems where they would keep running after the ignition was turned off - the extra quench distance often filled up with carbon deposits that would act as a secondary ignition source.
@@dangraff8467 Leaded gas was not necessary for high compression - its use was as a valve lubricant and sealer, Newer engines have hardened valve seats and other design features that live just fine even at high compression ratios without needing lead.
@@MisterMikeTexas It seems funny now, but I can still remember people shutting off their car, getting out and going into their house - and their car would still be sputtering and dieseling on! We blamed it on emissions equipment, which was only partially correct. It probably wasn't for another decade before many people/engineers understood excess quench distance as the cause.
By meeting EPA standards *without* a catalytic converter, Honda likely realized significant savings on per unit material costs. Subsequent success of Honda as an automotive manufacturer suggests that they made sound engineering decisions. On the subject of the Impala retrofit: I'm guessing that a properly engineered CVCC system for a Chevy 350 would have taken a tremendous amount of development, but may have produced better performance. I speculate that the only reason Honda did this was to promote the possibility of GM licensing CVCC technology. Anyone who was familiar with GM engineers at the time knows that they suffered from severe "not invented here" syndrome; this was never going to happen.
My dad was an engineer for GM in the late 60s and early 70s and quite the forward-thinking person. GM being stuck in the mud of their own choices is why he left after they refused to listen to what he said about the THM200 being a POS.
I'm a chemist and it's fascinating to see the shift in the gases emitted, especially in the changes in carbon monoxide and carbon dioxide. These two gases are related to each other in something called the Boudouard reaction, and their admixture can be affected by the temperature in which they are formed. Any data related to engine heat management would be very interesting.
I know only the basics (and my wife is a chemistry teacher and I have an engineering background); however that was far beyond the scope of this video! :)
I can't offer data but better emissions and more power is why today's cars engines operate at high temperatures. In the 60's a 180 degree thermostat was considered 'hot' while today many cars run 190 degree thermostats as standard.
Carbon monoxide and carbon dioxide are related to each other. One is an extremely deadly poisonous gas, the other is a life-giving gas. Carbon monoxide is one part carbon to one part oxygen it kills its victim by robbing its body of any Oxygen it can Rob so as to be carbon dioxide rather than monoxide. No amount of carbon monoxide is safe. It is the result of incomplete combustion of either carbohydrate fuel or hydrocarbon fuel. Carbon dioxide on the other hand is two parts oxygen to one part carbon regardless of whether it comes from respiration or combustion. It is a naturally occurring gas. All living things that are not a plant breathe in O2 and breathe out CO2. Plants do the reverse they absorb CO2 sequester the carbon and release the oxygen. Without this process no life could exist on this planet. Carbon monoxide is a deadly dangerous pollutant whereas carbon dioxide is a naturally occurring gas that gives life to the planet. It is not a deadly dangerous pollutant. It has no effect on the atmosphere or the climate.
Thanks for this, never knew about or heard this story. Growing up during the 1970’s, American car manufacturers didn’t seem to take the Japanese auto makers seriously and for the most part not many American car buyers either. They were considered ‘novelties’, toy cars and can even recall some friends of family going as far as calling them ‘tuna/sardine cans’, and jokingly mocked them compared to ‘REAL’ American cars! Oh I’m sure the Japanese manufacturers were quite well aware of this and throughout the 70’s and 80’s, stopped at nothing to change all those perceptions and misconceptions. Fast forward to the 1990’s and later some of the greatest small performance cars are from Japan, and while the American Auto makers are in a mad scramble to go FULL EV, again, Japanese manufacturers know it’s not the answer - just yet, and opt to go with PHEV’s and a few BEV’s just to say they have them on the market and ‘appease’ markets and regulatory demands for them. But ultimately, where the big three dominated the industry, it was their shortsightedness, and stubborn arrogance that led to the makers of rinky-dink, toy cars to dominate the auto industry and most American roads and highways today!
@@yourhandlehere1 That’s nonsense. While the Japanese may produce significantly higher quality drivetrains due to a cultural proclivity for attention to detail, etc. They don’t have any magic dust that they can sprinkle into an engine or transmission to make it last forever.
@@yourhandlehere1 How many miles are on the drive train? What service has been done to it over the course of its life? Did it spew magic “lasts forever” dust from the exhaust all the way there and back?!? 😁
@@markteague8889 Are you asking if cars and engines require maintenance? Yes, they do. Regular (frequent) oil changes, good filters, grease in all the fittings, fluids kept up. It's currently showing about 75,000 miles again...I've lost track of how many times it's rolled over. Really sorry if you decided to buy a Dodge or something.
Early in my career as a mechanic, I worked on several CVCC engines. Aluminum head on a cast iron block had issues blowing the gasket if they were overheated. The small CVCC pre-chamber was prone to carbon/coking up, significantly affecting performance. The chambers were also a challenge to pull out of the head casting and completely clean during a rebuild on the head/valve job. Amazing change once it was all back together and flowing air/fuel correctly and all 3 valves were reconditioned. The pre-chamber valve head was about 12 mm/1/2" in diameter and the hole into the main chamber was 6-7 mm. Usually restricted with higher mileage. Later version had two holes to create more vortices. Great engine, but not without some issues.
volvo was early In 1978, the Volvo 240 earned the recognition as the USA's Cleanest Car from the California Air Resources Board. In 1976 Volvo Cars presented a world first in the environmental area - the three-way catalytic converter with Lambda sensor for exhaust emission control. "The most significant breakthrough ever made in the control of vehicle exhaust emissions”. So said Tom Quinn, chairman of the California Air Resources Board (CARB), when the 1977 model of the Volvo 244 equipped with a Lambda sensor system was launched on the American market in the autumn of 1976,
@mjg263 Unless it went further than our 1977 Ford LTD II at 532,000 miles on the original engine, no it isn't. People admired the Ford for its reliability and styling......no one would ever make that comment about a volvo.
Interesting thing with the fuel economy. If you look at the bottom of the page where it says NOTE: the modified Honda Car had a different axle ratio of 3.08 compared to the Stock 2.73. Axle ratios directly affect fuel economy so that aspect of the test isn't accurately represented. Edit: and in other terms of this test, due to how chemisty works you will always have byproducts of a chemical reaction, you have a significant decrease in HC or hydrocarbons (aka unburnt fuel) and a decrease in CO (carbon monixide) which both occur due to an inefficent combustion (due to lack of Oxygen, or too much fuel) the increase in NOx and CO2 are due to an increase in combustion efficiency.
Fascinating story... and I did know about it. My first car was a CVCC (possibly an SB-1) and it effected my opinion of every car I owned, afterward. Insane fuel economy at a time when gas was not cheap. Better, is was light and fast with the impressive practicality of being a hatchback. The auto world could really use Mr Honda's kind of thinking, today.
Amen brother. Honda seems to have lost the innovative edge that it once had. They are still improving incrementally but no longer the leader they once were when the founder was still setting the agenda.
@@deanrhodenizer938 what makes ice cars not sustainable? We're not exactly running out of oil, and modern engines run clean. In fact, EVs are not sustainable, especially for the masses.
@@deeplyclosetedindividual They use fossil fuels... Yea, it will take some time to burn it all but the time will come when it is all gone, and... we really need those hydrocarbons for the petrochemical industry.
Fascinating story - I didn't know about this. One point of contention: I see this all the time when people compare fuel economy, where they say something like "1 MPG is a small difference". Whether that is true or not depends on the size of the number. For the CVCC vs. Stock at 45 MPH, the difference is 24%! That's huge.
at the same time: Honda retrofitted their tech on GMs car in very short order, there is no reason to assume that it could not have been improved over time.
@@uliwehner there is absolute proof. The Honda motor company itself ABANDONED cvcc technology eventually and that is more than enough proof that it wouldn't have ever worked right on a 350 Chevy engine. In 1979 when Honda increased the size of the engine a mere 9 cubic inches they had to use a catalytic converter to meet emissions.
My buddy picked up a 1964 Malibu with the straight six in the mid 80’s. For kicks they did an emission test on it and punched in that it was an 87 Chevy (Corsica I think). It passed.
Great story I never heard about! Thanks, Jon. The CVCC was superior engineering for small 4 cylinder engines that were way more fuel efficient compared to the large V-8's most American cars were running. The higher fuel usage CVCC created was hardly noticed on a small 4 cylinder fuel sipper - on a V-8, the lower mileage was dramatic. The GM Chairman's condescending answer to a press question addressing CVCC was par for GM at that time, even though apparent from the later EPA test results he WAS telling the truth. I think GM had probably tested and tried the CVCC system for themselves. Mr. Gerstenberg was no engineer - I think he was a finance guy - but GM certainly had the resources to investigate the Honda system and most probably did. The other thing was that the Big Three, including GM were jointly lobbying the EPA at this same time telling them that the emissions standards couldn't be met because they were loath to spend the billions it was going to take to meet them. Once the federal government dug in their heels and said the automakers had no choice - GM invented the catalytic converter and preserved the V-8's Americans loved and wanted to buy. The emissions standards were met, all the air pumps and add-ons went away and cars ran better and got better mileage to boot. The GM developed catalytic converter technology went into use industry-wide and is still used today. Even by Honda. If Mr. Gerstenburg made any mistakes; it was being arrogant in his dealings with the press and dishonest about GM's ability to meet the standards, (which they quickly did.) GM has always had engineering resources like no-one else in the business. Unfortunately, they've also had more than their share of short-sighted executives who couldn't see past the next quarterly earnings statement making the big product decisions. Honda, being much smaller and less hidebound, usually allowed the engineering cream to rise to the top and fostered a well-deserved image of a scrappy, creative company producing great products.
Great comment and additional history. As I recall, their lobbying worked to get the standards delayed; I want to say the President put the standards off for 2 years? I'd have to go back and look at that again.
Dunno where you get the idea that air pumps and other add ons went away with the advent of the catalytic converter . Many cars still used air pumps , and all still used an EGR valve and other stuff .
Yep, GM was being run by people who had no real engineering or production experience but they thought they were great managers because they were making a good profit today. So down the road they "managed" to turn what was once a "blue chip stock" company into bankruptcy because of that. A problem we still have today all across corporate America where people believe that management is only about managing and no experience with what they're doing is necessary.
at the bottom of that epa test result for the impala it states that the stock impala had a higher rear end ratio than the cvcc, that would have significantly affected the results for the fuel economy
As would power to weight ratio, power curve of the engine, drag coefficient, transmission loss, rolling friction, etc, etc. Axle ratio is a factor but in no way directly comparable.
Yeah even identical cars with just a ratio change would make a big difference, my car came with a 3.08:1 diff, i put a 3.46:1 diff in, fuel economy went from 830km to 60ltrs freeway driving, to 620km/60ltrs City driving got better, if im in traffic and things, economy went from 500km to 600. So its a big deal. Not to mention untested things like tyre pressure, the ambient temperature of the day, the fuel used, lubricant oil level etc
Good catch! That 2.73 in the stock 350 would have been MUCH better on fuel economy than the 3.08 on the CVCC, especially since they were testing on a rolling road dyno. No weight, drag or other factors to skew it. I don't know the math, but someone out there in Internet land could probably calculate the difference in engine RPM. I wonder if they even had the same tranny...?
@mojoxerspootykat594 at 60 mph 2.73 would be ~2062rpm 3.08 would be ~2327rpm, so about 13% higher rpm for the cvcc engine. The cvcc engine got roughly 13% worse fuel mileage at 60, however the rate that fuel economy diminishes with rpm increases is not linear, and it would probably do better than a 13% increase in economy with the reduced rpm.
@@jameswolfe8065 you believe a stock 350 emission motor actually got 19mpg? Maybe 15mpg I might believe. Most 350s I have driven got 12 to 14mpg. But manufacturers exaggerated back then or cheated the system.
What caught my eye was the 3.08 axle on the CVCC car vs the 2.73 axle on the stock 350. I was driving a fuel delivery tanker during that season of 1973-4 and I recall the manipulated and manufactured “fuel crisis.” I also recall a short seminar showing a full dozen add-on emission systems on the new 1974 Fords, turning the cars into total dogs.
I saw that as well. I currently own 2 Grand Marquis; one is a 1995 with a 3.08 and the other is a 1996 with a 2.73. In my experience, that is good for about 2 mpg. Sharp eye dude!
@@Adamroable The video didn’t say anything about Honda changing the drivetrain, 3.08 and 2.73 were both available options. My assumption is that’s just what the dealer had available
I know for a fact (friend was a NYC employed mechanic) assigned to the NYC Police Dept.from the early 70's till he retired in the early 2010's. I was a foreign auto mechanic at the time specializing in Japanese cars Toyota, Datsun and Honda. My friend in early 1974 came to me to tell me that there was a 74 Chevy Impala (RMP) assigned to the PCT that had HONDA parts installed on it and it was a test car for Air Pollution. He at the time worked at the 122nd Pct Staten Island N.Y.
Great post. My father had a 1973 Impala new. I remember sometime between 1975 and 1979 he had to remove the air pump because the car was running like garbage. There it sat in the shed next to my bicycle until he purchased a new 1979 Bronco and threw the air pump in the trunk to trade the car in. I believe the air pumps were a cheap way to dilute the exhaust emmisions, allowing the old motors to keep being used. Wouldn't the same dilution happen after the exhaust mixed with environment? Just a PPM altering device that helped nothing.
It wasn't just diluting the exhaust. It was a cheap way to reduce HC and CO emissions by burning them off in the exhaust manifold with extra oxygen. It's been used in more recent times on some engines as well to reduce cold start emissions before the converter warms up, though it was generally a band aid to get an old engine design to pass new emissions standards for a bit longer without a more significant redesign.
@@61rampy65 I am wanting to say the last car I owned with an AIR pump was a 1991 Ford LTD. I don't think any of my current cars have it. (1995 and 1996)
They started selling Honda cars in my hometown in 1974. My dad went and looked at a Honda CVCC and liked how it drove. He didn't buy it; instead he bought a Maverick. Honda used to advertise the fact their cars were able to operate without a catalytic converter, I believe, until maybe 1977; some time after other manufacturers had started using them. While they had that CVCC engine, at the time we looked at buying one, they didn't offer a fully automatic transmission. I think it was called "Hondamatic." You shifted, but there was no clutch. Great video!
I had and worked on an 83 Civic, which had the ASCC system, which was a further development of CVCC. It did have a lot of vacuum lines, but they were mostly easy to get to. An 88 Wrangler that I had later was a complete spiderweb of hoses.
Quite a fascinating story Jon. There are several reasons why the results are as they are. Firstly it looks like the CCVC engine is running a lot leaner than the stock Chevy - you can tell this by the low CO/HC and higher NOx. Any engine will demonstrate this trade-off. What the CCVC does is allow lean mixtures to be reliably ignited compared with (then) conventional combustion chambers allowing good combustion stability and running smoothness. Where it loses to a conventional combustion chamber is in two areas - increasing surface/volume ratio and increased pumping work - i.e. the energy loss of the gas moving from the prechamber to the main chamber during combustion and expansion. Having the relatively large fraction of combustion gas flow at high speed through the throat connecting the prechamber to the main chamber also increases heat loss to the cylinder head which, along with the higher overall chamber surface area means the waste heat to the cylinder head and cooling circuit causes greater fuel consumption/poorer "gas" mileage. (nb: don't confuse gas with "gas"...). Interestingly I don't think Honda would have spent a fortune developing a one-off demonstrator so chances are high that the system developed for the Impala and Vega could have been substantially improved in all aspects. I suspect that the additional costs of extra valves, more complex carburettors etc wouldn't have won over the beancounters though and this may have been what reduced its widespread adoption. Also interesting is that this style of pre-chamber combustion system has made a resurgence via F1 into production cars (noteably the Maseratic MC20 so far) where a small prechamber (passively filled in the case of the MC20) is ignited to create a high velocity "jet" ignition source in the main chamber. Mahle are proponents of this system and you can see their promotional video here: th-cam.com/video/n6Eutw0WU3U/w-d-xo.html
Thank you. I had heard this story over the years and it never changed. I heard that it was the head change only and it made more power and the MPG jumped by over 25% increase. Thank you for the rest of the story.
The cvcc system, in paper seems simple. Have you ever worked on one? That carburetor was a nightmare, with all those vacuum hoses. I forget a lot of things. Not what pain in the butt ALL of the mid 1970's and later carbureted engines. Honda in time dropped it and adopted fuel injection and a nice system to boot!
The CVCC was no fun to work on, but they were tough little motors and ran forever! By the time Honda brought out the PGM-FI their motors were incredible! In fact I think the late 80's early 90's saw the best motors to ever come from them.
@@christopher88719 Indeed! I think a lot of manufacturers had their best engines in the late 80's and 90's. Down in power by today's standards but a lot more reliable and easier to live with!
at 20 mpg, which would've been pretty good in early 70s; 20% is 4 mpg. 16 vs 20. Slightly worse is mostly appropriate vs 20% at 60 mpg 48 vs 60; but if you were getting 50, you'd not be complaining. To have the numbers mean anything, they have to be bigger. if you make 100k a year, a 20% pay cut is a huge 20k or around 400/wk. If you make 15k a year and get a 20% pay raise is around 50/wk. In the end, how people drive and think about driving would make the biggest difference. I drove a 75 Pontiac that no matter how gentle you drive, would get 9 mpg. 20 would be heaven in that thing.
Ford developed "lean" burn engines in the 1990's and they were actually sold until the EPA decided that they created to much NOx. The fuel mileage was impressive in some cases with 6 cylinder engines improving fuel mileage over regular 4 cylinder engines. Interestingly GM had a few years of lean burn engines in the Corvette in Australia as well. Those cars were known for good performance and improved fuel mileage. It's interesting that stratified and homogenized mixtures/cycles are still being studied for direct fuel injection as well.
Ford in Europe introduced 1.4 & 1.6 lean burn cvh engine around 1986 Europe, I think there might have been more lean burn engines from ford Europe but I can't remember
Fast forward to 10ish yrs ago. Can you imagine how the Japanese engineers were ripping their hair out,trying to figure out how VW could make a diesel pass emissions and they couldn't? They wanted in the small diesel market really bad at that time, that really had to have them fit to be tied.
My mother has a Saturn Vue that partly came from that Japanese diesel program. Honda bought GM diesel engines for the European market and GM got Honda 3.5L gas V6s and 5-speed transaxles that went into the Saturn Vue. The V6 model has a big J-shaped air intake plenum that makes it obvious the engine wasn't designed for that chassis. But that smooth 250hp V6 is easily the best part of the car.
@@skylinefever it actually worked out really well for the customers. I bought a Golf TDI, owned it for 2 years, then sold it back to VW for more than I paid for it.
I have been wondering when someone would put a spotlight on this story that I have known about for decades. I am quite surprised that a movie has not been made about this, like the movie "Tucker", or "Flash of Genius". Thanks for putting this out!
@george9417 Yes, it's known as a "hegelian dialectec" (create problem, pretend to have solution) that restricts people's freedoms in allowing real innovative products to come to the marketplace, that will vastly improve the quality of life for the majority of people. Yeah we are "bootlickers" using out Federal Reserve Notes to transact business in the establishment , run by the individuals that the seal on the reverse of the US $1 bill depicts!
Well put. I subscribed... & am looking forward to whatever else you've done. Remembering with wife's 1st car, the civic, turning on AC ment needing to downshift to 3rd... they've come a long way.
My Audi had the same problem, turning the AC on was like hitting a wall of marshmallows, in those days Audi bought its A/Cs from GM, when the Japanese got their own compressors, the result was about half the weight and half the power consumption of the GM units The GM units were fine if you had a big V8 and didn't care about gas mileage. Nobody uses the GM designed compressors anymore and GM no longer makes refrigerators, selling that business as well.
The irony of the emission standards and greenhouse gas emissions is that as you reduce exhaust gas content for HC & CO you increase CO2. So it makes perfect sense that the CVCC produced more CO2. This is addressed with FI & O2 monitoring which cycles the exhaust alternately from rich to lean to activate the oxidization and reduction beds in the catalytic converter.
Hi Jon, good video! I am 63 years old and have been a automobile mechanic most of my life. It's not the emission control(s) that rob the horsepower, it's the lean air/fuel mixture that takes away power and good drivability. The EGR "exhaust gas recirculation" valve is to cool the combustion chamber so the engine can run lean with unleaded fuel. Please reply. Dave...
If nothing else the overall quality of any Honda puts any GM to shame. I've owned both and know it all too well. The most I could get out of any Chevy was 115K miles before the timing chain gear lost all the plastic. I put 216K miles on an Acura and didn't change anything but brakes, wiper blades, tires and a battery.... plus it got 36 mpg.
Yes, 3.8 V6 had Teflon coated timing sprocket. The engine was good for 90,000 miles. I knew this, but the 3.8 V6 was a great engine. I bought an '87 Olds 88 f.w.d. with a junk yard engine. I replaced the timing sprocket, and got 200,000 mi. The engine was good when I junked it.
you talk crap about a chevys timing sprocket at 115k, yet fail to mention the timing belt on your acura probably looked like the ground at desert valley.
Those variances partly came from the different rear end ratios. The Honda 350 was running a shorter gearing which means the engine would have ran at higher rpms comparable to the normal engine. That may not account for all of the discrepancy shown in emissions and fuel economy, but it would have an impact.
my dad bought a 77 Honda Civic but it didnt have the CVCC. at least it didnt have the badging. the engine was a 1,230 something cc displacement. with a 4-speed manual, and driving it conservatively it still only ever got 25mpg. fun car nontheless
Soichiro Honda built very few 2 cycle engines compared to how many were 4 strokes. Just about everything Honda built was 4 cycle, motorcycles and cars.
Back then two-strokes didn't last long in comparison to 4-strokes, and Sochiro was OCD about making the best possible products he could so that his customers got the best value possible. It wasn't the most profitable approach, only the best one. Too bad nobody else has followed him.
Really curious if you noticed the rear end gear difference in the 350 testing vehicles. It looks like they attempted to adjust the dyno to match but the CVCC engine would still be running at a higher rpm at all measured speeds. Interesting comparison and seems like the Impala and Vega stories have been melded together over time.
I have worked on those Honda heads. They had a problem with the auxiliary valves getting carbon deposits built up on them. Sometimes it was so bad that the passage was completely closed off. Those engines were also covered with vacuum hoses.
18 mpg for an Impala with a 350 is pretty good. But an apples to apples test would have been a '75 Impala with a 350 after it received both the EGR and Catalytic converter. I remember these cars struggling to get 14 mpg. We had a new Camaro with a 305 in '76 and 18 mpg was the norm. Also did you notice the difference in the rear end ratio? That would have made a noticeable difference in mileage as well. I get that they were testing what was being built at the time but in actuality the CVCC system would have gotten better mileage while also producing less emissions than a truly comparable 350 engine with the aforementioned controls. Cool video though, those were dark times that have never really gone completely away.
Had some friends back in university that had a Honda with that engine. That was one tough car, it got by on poor maintenance and hard usage. I don't remember them ever having trouble with it or saying a bad word about it. Meanwhile I was driving a Buick hand-me-down from my aunt and uncle that couldn't go 10 miles without breaking. Car was lowish in miles and my Uncle had babied it so it wasn't just that it was worn out. Was a happy day when I saw the back end of that car going down the road.
I bought a 1980 CIVIV w/CVCC in 1983 as my college car. It lasted until 2003, with over 220,000 miles. The engine was solid, I never had engine problems, or fuel system issues (carburetor). I changed the oil every 3,000 miles, and that was it! Likewise, I never had transmission problems, other than two clutch plates replaced.
It might have remained in production longer if an EFI variant was built. Japan had an EFI CVCC engine, it was in the Honda Bulldog Turbo. Those had a 1.2L turbo engine, but I suppose it could have been applied to the largest NA CVCC engine. If there was a need to make a more powerful Honda, they could have applied the turbo to larger CVCC engines. The reason Japan got some extra small engines was because cars were often taxed by engine displacement. That also motivated Japanese car companies to build forced induction engines. The displacement tax is why their Datsun Z-car (Nissan Fairlady Z S30/S130) often had 2.0L engines.
@@skylinefever I think moving to 4 valves per cylinder is more the case. the EW which probably had the final iteration of CVCC forgoes an extra exhaust valve for the CVCC chamber. It would have been interesting to see further developments. An also Japan only fuel injected EW with CVCC made 110ps. Seems pretty alright for a 1.5 although more powerful engines like the d15b would come later with more modern head designs
Honda cvcc engines didn't last very long though. They failed to mention this. They went through heads quickly and were very expensive to repair. I always avoided them when looking for used cars back then.
I've also heard that the CVCC engines were prone to carbon deposits, which caused driveability and reliability issues. Regardless, this is fascinating. I always enjoy stories of how the "little guy" beats a huge company at its own game.
I haven't seen a cvcc Honda since probably the late 80s on the road. They rusted worse than any other car I've seen. My uncle bought one ,and brand new it had surface rust at all the sheet metal bracing under the hood at the edges. They started rusting on the way here on the boat.
@@MrTheHillfolk yes for sure. I live in a snow belt. Same here. The strut towers would literally break away from the fender. I used to see them pushing the hood up a bit sometimes. Lol
last time I saw my 300k miles cvcc engine.... car ran great up to that . the head may have had a problem... not certain. I think the fuel leak near the carb was involved. but honda had no parts for the repairs I wanted to do.
@@MrTheHillfolk oh man they were terrible rustbuckets. Great technology but dang, they did come off the boat with rust. Toyota too. We called corollas “corrodeds “.
I still have to wonder to this day, with results like that at 12:15, is it better to get more mileage out of a gallon of fuel, or is it better to use more fuel with cleaner tailpipe emissions? I remember working on 6.4 Powerstrokes that were getting 8-9 MPG with a particulate filter, but 20-22 MPG when deleted, plus who knows what emissions emitted to produce the particulate filter system.
This is excellent. I have never heard this story either. Imagine that...GM acting like they were high and mighty. Well, ok, they were high and mighty at the time, but many of them also knew they were beginning to struggle.
In 1975 my wife went out and bought a Honda CVCC with Great gas mileage, lots of power, trouble-free. The price was outstanding! We ended up buying two others. Best cars ever built. Today we feel betrayed by Honda. At some point they priced themselves out of our price range. Today we are retired and on SSI and in need of a new car. SSI does not allow for things like the need of a new car so I'm driving my old 99 Olds van and my 99 Ford F-250! Bring back the CVCC!!
@@crazeguy26 In the late 80s, there were no VTEC engines, but Honda ended the CVCC. I think they decided to use EFI and stop making CVCC engines. Not that they couldn't make an EFI CVCC engine, the Japan-only Honda Bulldog had an EFI CVCC engine with a turbo.
@@camillosteuss and you are so right about Americans. Easy to spot as tourist in my land. And I prefer kilos, too. But a lot of this channel are from US I think, a d they have an aversion to metric measures.
@@suzi_mai damn, at least my common sense put me to correct conclusion that you meant the engine and trans... and i dont care about imp vs metric, i handle both, im a machinist, so that shit is all over the place and nothing unusual to me... hell, i even mix them and match them depending on work i am doing... and welding, 1mm is 40 amps, but 40 thou is 40 amps, so you know that any sheet of steel i see i instantly convert from mm that is my default reference into thou of an inch...
Even before Honda was experimenting with this, There was the Texaco combustion process in the late 50s/early 60s where a 430 ci Lincoln engine got amazing fuel economy but had one issue, it had to be driven in order to get it warm enough for the heater to work. The combustion was a stratified charge system so in low load, low rpm running the combustion was a ball that never reached the cylinder walls. This I believe is what evolved into the Ford PorCo system.
The Texaco TCCS engine was more or less a spark-assisted diesel engine running on gasoline. Or, to be correct, it used some kind of kerosene. TCCS did not require high octane or high cetane numbers for the fuel. Thus, fuel refining could be simplified. TCCS had a big drawback since it produced lot of smoke (and particulate matter at full load. Its power was "smoke limited", just as a diesel engine. Here Proco had an advantage, since it used premixed combustion at full load, via early injection. TCCS had "late" injection (near top dead center) and thus, there was not sufficient time available for mixing fuel and air to the molecular level, which is required for smoke-free combustion.
I just love the idea there’s fancy Honda Cylinder heads for a Chevy 350 somewhere out there. I saw an article about this somewhere in my 70’s Motor Trend or Car Craft. Always wondered about more info. Thanks.
Nah, proper CVCC heads have an extra valve & chamber for a rich fuel charge. That’s what I thought was interesting for a set of 350 heads. Hell, the spark plug on a CVCC head is tucked away in that rich mix chamber like an indirect diesel injector. It’s a goofy setup and Honda went Madlad & put it on an American V8.
@@chaseman113 Soichiro Honda also ordered a 32-valve 4-stroke oval piston V4 engine be built for motorcycle grand prix racing after all! It was supposed to compete with two-stroke engines of the same capacity by revving twice as high (it was not a success!). Mad ideas were kind of his thing by the sounds of it, lol. 😊
my then-wife & I bought a '74 Civic CVCC. We loved it. Comfortable, roomy, good power & great handling. A friend I worked with (over 6') traded in his Vette for one because it was so much easier to get in & out of & was more comfortable.
Cool story! One thing though - Honda had stopped "only running two stroke engines" back about 1952. I do not recall Honda making ANY two strokes back in the '60s. The general consensus back then was that Honda HATED two strokes. By the mid '60s, Honda was one of the world leaders in four stroke engine technology. Their first four stroke, the Dream E was released about 1952. They were the worlds largest motorcycle manufacturer by 1959, most (if not all) four strokes. By the mid '60s they were winning world motorcycle GP races with their 17,000 RPM four and six cylinder four stroke engines, competing against the two strokes. They were also racing F1 with their 1500cc V12's against Ferrari, etc. By the late '60s they had almost wiped out Harley Davidson and the entire British motorcycle industry. This was basically ALL due to their very well engineered four strokes.
I apologize if I got my facts wrong on that. I had a source that talked about Honda *not* having a 4-stroke (for their cars) until the Civic engine was completed.
@@AllCarswithJon No problem! Still a neat story I had not heard before! A bit of irony - the 350 Chevy is easily the most common racing engine in history (cheap horsepower...)
@@ldnwholesale8552 No. Honda never made a two-stroke car and after the early 50s, they did not make another two-stroke motorcycle until the motocross competition-only 250 Elsinore in 1973 and it's street-legal trail bike version in 1975. Are you, by any chance, confusing two cylinder engines with two stroke engines ?
@@CaptHollister yep! Honda motorcycle service tech for 45 yrs. I recall two twin cylinder air cooled 4 stroke cars in the late sixties. Basically just large motorcycle engine adaptations. I brlieve one was the E600 sedan. My boss that owned the Honda motorcyle dealership at that time drove them. Really small...even compared to a later Civic.
Thank you. I was very aware of the CVCC engine when it came out but I had not heard this story. I was a teenager back then and did lot of servicing on Honda 4-Stroke motorcycle engines.
the EPA test results are consistent with a poor adjustment of the main and cvcc carburetor barrels. I have worked a lot on the CVCC engines and take my word for it, it you lose milage values, your CVCC aux barrel is not set correctly. I suspect the vortex chamber was too large...
Interesting. My understanding is the NOx is what caused smog. So not only did it get worse gas mileage, it caused more smog. So they lost on both counts and they lied about it. No surprise. GM had the catalytic convertor on since 1975 and that was and is the right solution even today. Sounds like GM embarrassed Honda, not the other way around.
I have an '82 civic and live in California. There's a vacuum leak somewhere. I'm trying to sell it. I think that pretty much sums up my experience with cvcc. It was badass back in the day but when no technicians know anything about it and you don't have the time or tools or money to track down all the problems, it becomes impossible
Our 85 Civic Wagon with Cali-spec emissions was great up until it had 250,000 miles on it. Then all of those tiny vacuum hoses and all of those black boxes started to give up due to blistering heat in Texas. It wasn't worth the money to have a specialist fix them all. At least they gave us pretty good trade-in value.
Smoke test the emissions system. You can also just go ahead and replace every single rubber vacuum hose and their plastic connectors. We had similar issues and it's easier to just swap all those parts out and not worry about it.
@@marthamryglod291 Agreed. Get the vacuum line diameter specs, and buy 20+ feet of it. Replace all the vacuum lines one at a time, and it'll be fine. I did this with a California spec 1983 Toyota pickup. Just make sure you don't mess up the routing, by doing them one at a time.
The advantage of Contoured Vortex Controlled Combustion is that it's a really cool name. The disadvantage is that it's too expensive to mass produce. So Honda kept the name and went to a stratified combustion engine. It was a great engine. I had a little '76 Civic wagon and it was probably the best car I've ever owned.
Very well explained. I believe Japan kept with their designs mostly because of their form of the average typical driver. Being in major cities where there are alot of start and go traffic, there wouldn't be often situations where you would be wide open throttle/high speeds for great lengths in time. Just a guess or plausible based on the generation and what I recall of the infrastructure of that time.
GM is really good at making corporate decisions that don't work. When they bought Lotus they had 2 choices to power the new bodied Corvette. 1. was a motor designed in house by the same guy that designed the quad 4 motor for Oldsmobile, a quad 4 engine modded into a 5+L V8 was proven to put out over 500hp reliably. 2. was the lotus V8 plagued with known problems.
When I was still a wee lad back in 68 we lived in NorCal, and Dad drove us to Disneyland. As we got closer I saw what I thought were storm clouds over the city and was almost in tears thinking my dream vacation was going to be rained out before Dad explained that it was smog. You really had to see it to believe how bad it was.
I made the mistake of buying a new 95 Monte Carlo. It was horrible build quality and design. Absolute junk. Anyhow, switched to Ford with decent results. I still own a couple. But, when I want a great reliable car or truck… I buy Toyota. I’ve had several beginning 2003. Great products.
Axle ratio is the variable that is relevant to all these graphs.If this variable was equalised then then comparison would lean more in the favour of the CVCC tech.The fact that tiny Honda could provide this solution in months while the Big Three were claiming it was IMPOSSIBLE, hints at the lack of integrity in the big business oligarchy of 1970 USA.
I remember back in 1976 driving a Buick station wagon with a 454 V-8 that "couldn't get out of its own way" with a fuel mileage down in the single digits, then driving a Honda CVCC Civic that could move out like a "scared rabbit" with fuel mileage around 45 miles per gallon.
@@HowardJrFord I kid you not! I had a Honda CVCC Civic back in 1976. Front wheel drive and that critter could flat out move! One trick Honda did was to design the engine for high R.P.M. which gave the engine to ability to give high output with small displacement.
And to be fair, Honda embarrassed GM, yes, but specifically Chevrolet. At this time GM was still made up of AUTONOMOUS auto divisions, and Chevrolet had the poorest engineering, poorest engineering budget, or both. There was no saving the Vega, it was a flawed concept with flawed execution. The Chevy experiments with the Wankel rotary and FWD were SO BAD not even Chevrolet would put it into production. Not only was the Vega-based (H body) Monza directly and adversely affected, but also the AMC Pacer (lesson: NEVER depend on Chevrolet for your powertrain). Several times Pontiac had to bail out ***yet another*** Chevy engineering screwup. I suspect Honda may have had a more difficult time embarrassing another division, like Buick.
My last three vehicles have been a 62 falcon, an 85 town car and a 96 miata. The 85 town car had a 5.0 (302 ci) v8 with cats a smog pump and central fuel injection, falcon had a 170 ci straight 6 with a carb and the miata has a 1.8 (112 ci) twin cam inline 4 with obd 2 and multiport injection. As a backyard mechanic I learned my fair share and the smog and malaise era cars are just like the past two decades of the auto industry to me. There's beauty in the simplicity of the systems that are reliable and work well.
Great story! It definitely demonstrates how the big US auto companies with their huge engineering groups had some blind spots based on their inability to question themselves. 👍🏻
It's not just the engineers. It's the whole management oversight. The financial decisions. Cost cutting etc. Plus people need to realize that the equipment for manufacturing components such as engine machining lines are not something you just order and it shows up next month. The machining of transfer lines as they are called feature multiple stations that perform one specific operation per cycle. And every cycle the part is automatically transferred from one station to the next. One single set of machinery for machining an engine block can be up to a quarter mile long. From rough end to finish. And that's only doing the block. Add in machinery for the head or heads (1), bearing caps, connecting rods, intake and exhaustmanifolds, pistons, cranks, camshafts etc. And that's just the bare engine. All of this costs money. And once built and installed it is usually intended to be run a long time. I spent 30+ years working in an engine facility so I know something about the subject. 1) Depending on the engine design V type engines can require a seperate machining line for each bank.
@@seanm8030 Far too many years of riding with little to no competition. Plus the US auto industry decided to go all in on increased displacement with truely huge V-8s. Yes their were some 6 cylinders offered. The only fours I can think of produced domestically in the early 70s were for Pintos and Vegas. GM might have been building a four for industrial use unless the tooling had been shipped to Brazil.
I’ve worked on a CVCC Honda before, absolute nightmare of vacuum lines. Especially as they get older and rubber ages. Honestly one of the most complicated vehicles I’ve had to deal with
I had an 87 Prelude with the 1.8l twin-carb A-Series engine. Also a mess of vacuum hoses with the complexity of the human circulatory system. Save yourself a migrane: Just get a whole roll of vacuum hose and replace ALL the hoses one at a time
It's been nigh-on forever but IIRC there were 32 vacuum hoses under the hood with that engine and you learned to mark them all very carefully on removal. To Honda's credit it did work well when everything was right and allowed them to run carbs two years longer than anyone else could do. God help the mechanic who got one of these where some shade-tree idiot had messed up the vacuum hose configuration 😱
There was one interesting CVCC engine that might not have had so much vacuum junk. The Japan-only Honda Bulldog had the only EFI CVCC engine I know of. There was a turbo version, I don't know how much much vacuum stuff that had.
@@skylinefever Was that also the same engine used in the Japan-only Honda City/City Turbo of the same period? Always thought those were the neatest, coolest mini cars at the time!
Beginning in June '72, I started my first job as a young mechanical engineer having just graduated from Univ of Mich concentrating on internal combustion engines and was working for Ethyl Corp in Ferndale, Mich. Among a variety of research efforts, we also did engine dynamometer work for Ford. I was the engineer with eight technicians working for me doing that testing. Some time in late '72 or early '73, Ford purchased the rights to study/develop/produce the CVCC concept from Honda for $50 mil. (That's when $50 mil was real money.) It was big news in the industry. Ford then asked us at Ethyl Corp to setup the CVCC approach on one cylinder of a Ford 460 cubic inch V8 coupled to one of our engine dynamometers as a research tool which we did. It was indeed a research setup; it wasn't pretty, but it did function. We measured emissions levels in the raw exhaust as well as temperatures, fuel used by each of the two carburetors feeding the cylinder, and air consumed by the main chamber and the prechamber as it ran. The three pollutants emitted by cars that were identified in the Clean Air Act of 1970 were hydrocarbons (HC), carbon monoxide (CO), and oxides of nitrogen (NOx). The EPA then came into existence to enforce compliance with the Act. Standards were established for HC, CO, and NOx for the next several years until a reduction of (I believe) 99% was to be achieved by the car makers. As stated in the video, the car makers had little idea how they were going to do it. Running lean and most cars could meet the HC and CO standards albeit with significant performance penalties, but then they couldn't meet the NOx requirements because they couldn't run lean enough to achieve low NOx emissions. Running rich would allow cars to meet the NOx standard but not the HC and CO standards. The CVCC approach was on paper a clever way to run rich in a small prechamber, ignite the rich mixture, then have the flame from the prechamber sweep into the main chamber and ignite the lean mixture above the piston thereby pushing it down and producing power. Overall, with both the prechamber and the main chamber together, it was a lean mixture but was optimized to keep all three pollutants low without the need for a catalyst for help. By the way, I know of no two-stroke engines in Hondas in the '60s as stated in the video. Did they have them in their own market in Japan? I don't know. All the Honda motorcycles in the U.S. were distinguished by their use of four-stroke engines while Yamaha, Suzuki, and Kawasaki, their main competition, all used two-stroke engines. As background, two-stroke engines use a rich air-fuel ratio to aid in cooling and emit large amounts of HC and CO. They could not be used to meet the exhaust emission standards in cars. Meanwhile, the application of the CVCC approach on the 460 ci engine was halted a month or two later by Ford after we produced data for them, and we never heard many of the details as to how it was judged by Ford's higher-level engineers. A little over a year later, I left Ethyl and started working for of all places the EPA in Ann Arbor while going to graduate school part time. I worked there a little over four years and worked on motorcycle emission standards (which forced the industry to stop producing two-stroke engines though standards were never promulgated) plus other regulatory papers and such. I watched as exhaust emission standards became more and more stringent. Model year 1974 was a tough year for the internal combustion engine as power and fuel economy was at a low point. Catalytic converters using oxidation catalysts were the norm for cars beginning in 1975 with some power and fuel economy returning. Honda as well as all the rest of the manufacturers eventually came to rely on what is known as three-way catalytic converters where the air-fuel ratio is precisely controlled through use of fuel injection and sensors and HC, CO, and NOx are dramatically lowered making car exhaust consist almost exclusively of CO2 and water vapor. Cars nowadays are clean and capable of extraordinary power and fuel economy. It's a tribute to the industry ... including Honda and General Motors as well as Ford. As a final note, Honda is technologically very capable, there is no doubt. However, Honda has recently agreed to buy GM's Ultium battery technology products going forward to be installed in Honda vehicles. Honda (and Toyota, too) underestimated how quickly the industry would transition to battery electric for power. So, I wouldn't sell American capability and technology short by any means. There are smart people involved all through the whole car industry.
Fantastic comment and thanks for it! A couple of things: First, yes I did seem to get the point about the 2-strokes all wrong; I have it in my script/outline but I think I must have had a 'senior moment' and dramatically misquoted something. Sorry about that. Second, there's no doubt that Ford and GM have the capabilities, but they haven't always turned that into products quickly or reliably. Personally, I really like what the domestic manufacturers are doing right now and that they're near the front for the move to EV.... so much so that Honda needs a GM platform to hold them over while they develop their own.
@@AllCarswithJon to add to that, Car & Driver magazine recently came out with its 10 Best cars. Three of those cars were GM cars. Mind you, C&D is not a shill for domestic manufacturers. On the contrary, they consistently and inexplicably side with European cars. GM is making outstanding cars. Can you get a turd? Probably, but Toyota has them, too. All things equal, American workers need people to buy American cars. Designers, product engineers, manufacturing engineers … they’re my neighbors, my relatives, my friends. There’s too much bias against domestic brands. Thanks for letting rant a bit. BTW, your video brought back a bunch of memories. I worked with a lot of good people at Ethyl and at the EPA.
1st cvcc civic was 1975 ...the 1200 debuted in 1973. Bestest cvcc ever was 1976/77 accord. I still have the shop mans after 40+ yrs. btw.. when in us army in 70's ..found cvcc design in Russian tech journals..true story frm a 45yr vet of Honda service still fix em everyday!!
The higher fuel consumption is also reflected in the much higher CO2. Something tells me it wasn’t quite sorted as far as fuel mixture goes. That’s a substantial increase in fuel consumption suggesting the fuel mixture was very very rich. I find it hard to believe that it couldn’t have be made to perform as well as the smaller engines with more development, maybe involving a different or modified carburetor. Trying to modify a Rochester Quadrajet must have been challenging. Too bad, but cudos to the savvy engineers at Honda for trying.
I had a 71 Cutlass 350 and it got about 15 to 18mpg if I kept my foot out of it. That was the last year before they started butchering them with dropped compression, low cylinder TDC for fun dieseling, airpumps, etc...
ignorance is not a reason to reject a change. Yes they required new learning, and setup procedures had to be followed EXACTLY. Something most American mechanics couldn't adapt to. In Japan they had no issues maintaining the vehicles. Same can be said for Mercedes Benz vehicles, factory maintenance procedures needed to be followed. Or the vehicles ran poorly or had "reliability" issues. Just a different mind set than was typical in USA.
I really enjoy your videos. Just a suggestion, the lighted item on the shelf over your shoulder is really cool looking but quite bright and distracting to your presentation. This is a great story, I've never heard of it ! Thank you !
They were. Mary Bara has done wonders with GM but they're still struggling to overcome the crap reputation of the past with almost no money to do that with. The car market is a very tough bullseye to hit these days.
I think you meant their over head cam technology was more adept to the cv-cc not their over head valve. Almost all the US automakers were building single cam in block with pushrods to actuate two over head valves per cylinder. By comparison the smaller Honda motors are over head cam and later three and four valve.
1980 Accord?? With the trim all collapsed in the sun. the Honda zeem blowing blue smoke and the general driving experience generally poor. And ofcourse the rust they all have. Three year throw away car. Yes I have owned those things ever only as trades
@@ldnwholesale8552 Dunno. At the time the competition was the joke Plymouth Horizon, etc. It had european econocar roots. I sat in one- a joke. The Honda sedan looked like a tiny Mercedes 300 and was neatly put together. I think I put 100k miles before I traded it. (That was a looooong time ago, btw. The video is about cvcc technology.) Take a peek: th-cam.com/video/4EsXqHpjTQU/w-d-xo.html&si=EnSIkaIECMiOmarE
People didn’t care about emissions or engine design they wanted reliability. My friend sold his Maverick in 1975 and bought a Corolla. He took a lot of heat over owning a tiny Japanese car. His response was always “I’ll buy an American car if you’ll fix it.” I always loved big American cars, but in 1988, I sold my 73 Olds Delta 88 and have been driving Toyota, Honda and Subaru cars ever since. When gas was cheap, I bought my cars by the pound, but the price of gas and reliability made buying American cars just plain stupid.
I had a 1980 Honda Accord with a CVCC engine in it. I abused the living shit out of that thing and it never let me down. The thing was bomb proof. The rest of the car finished it's life as a complete rust bucket and everything from the headlight pots to the door latch mechanisms were trashed, but that engine (and the 5 speed manual tranny) ran better than any other car I've ever owned.
Me too, i had a metallic green sedan, bought it cheap with 36,000km on it. Fixed a few little things on it and was to sell it, the buyer wanted it delivered to a vehicle transporter on the other side of the city, from the moment i started driving i wished i didnt sell it, it was comfortable, sounded good, not much if any road noise, felt awesome to drive, handled well.. It was just an amazing car. I wish it was my daily driver now. Modern cars dont feel like that at all
To add to the last post The 122nd PCT was probably picked Because it was the largest PCT. of all the police Pct's in NYC and the cars assigned there put the most mileage on the cars per year.
As we contemplate new government-imposed EV mandates, I’ve been thinking a lot about this era. The necessity of addressing smog, safety and strategic fuel shortages led to some pretty dismal products (Honda notwithstanding). Beyond the time needed to develop and launch a couple of generations of platforms, it was really only the widespread adoption of fuel injection and computerized engine control that brought drive ability back. Now the problem is even more urgent. I hope the battery technology is there, but I fear we’ve got another round of poor products we’re going to have to live with.
I tend to agree that any major shift like this has growing pains in the early generation(s). Certainly I can see range, charging networks, electric production and distribution, recycling of batteries, and wholesale upheaval in used car sales coming. The big difference is this has been brewing for a long time and automakers, states, federal govnmt, and other private parties are all moving forward... together. There will be bumps, but hopefully not as disruptive as the change from the 60s muscle cars to suddenly power-starved and thristy 8's of the 70s.
@@AllCarswithJon problem is the whole EV push is a disaster. number 1 the national electric grid will NOT be able to handle a huge amount of EV's number 2 the mining of the materials will cause a huge amount of damage to the environment vs current gas/diesel will. and number 3 the avg joe will never be able to afford the crap. you got people who duct tape junkers together to keep running cause they can't afford a $1K repair you think they will be able to afford $27K for battery replacement? no way in hell I could afford to just fork over $27K for a battery replacement I don't have that kind of money and never will.
@@Dratchev241 It's even worse than that. Meanwhile, as I type this, in Wyoming there is yet another trainload of electric car fuel, aka coal, rolling out of the state headed for a power plant. Every time you convert one form of energy into another, you have losses. To operate electric vehicles I see the following: 1. Burning coal to make electricity, which entails converting a. Chemical energy into heat b. Heat energy into mechanical energy c. Mechanical energy into electrical energy 2. Charging the battery, which entails converting electrical energy into chemical energy 3. Driving the vehicle, which entails converting chemical energy into mechanical energy. There are five energy conversions to move an electric vehicle In contrast, operating a gasoline vehicle involves 1. Burning gasoline in the engine to convert chemical energy into heat. 2. Converting the heat into mechanical energy. There are only two energy conversions to move a fossil-fueled vehicle. (I'm also ignoring the refining of gasoline and diesel, which do take energy and have inefficiencies of their own. The power plant can burn coal as it comes out of the mines. I don't know to what degree this offsets the three additional energy conversions with the EV.) For EVs to serve our needs as efficiently, cheaply, and yes, as cleanly as gasoline and diesel powered vehicles do now, there are going to have to be vast improvements in the way we generate, move and store electricity. And yes, when that battery won't hold a charge anymore, replacement looks like it will cost at least as much as replacing BOTH the engine AND transmission of a gas powered car. How long will a battery last? It's the same technology as cell phone batteries and they last what, 3-5 years? Probably not 26 years like one of my Subarus. The other of my Subarus will turn 24 in March, 2023. I drive these old cars by choice. I can afford a new car, I just don't like most of the cars that have come out since about 2010-too many new technologies at once, too much computerization, too much tracking, too much hackability by those who may not have my best interests at heart. Too much stuff that doesn't have anything to do with getting from point A to point B too integrated with the stuff that does. (I have heard of cases that if the radio breaks, the car won't start because a chip in the radio controls functions of the engine. Then there's always the possibility of a buggy or corrupted software update that breaks things rendering your car useless or even unsafe.) I want an automobile. Just an automobile, not a rolling smartphone. When and if these issues are worked out, I think EVs will be great, but there is a lot of work that will have to be done to get us there.
@@dr.a.w When you consider the entire life cycle of grid-powered EV's and what it takes to power them during that life, they are currently no better than petro-powered vehicles- possibly even worse for the overall environment and the average owner. I drive older vehicles due to economic necessity mostly, and by choice since I can maintain these myself saving me a ton of money. We've got some tough choices and tough times coming up in the future regards personal transportation and the right decisions will not be the ones people want to live with, so I think people like us are going to exist for quite some time longer.
@@dr.a.w While there is some truth to everything you said, it is amazing how fast people and technology can adapt when forced to. There has been more research in batteries and alternative energy in the last 10 years then in the previous 40 years before that. There are tons of promising developments that people are investing heavily in creating the ability to mass produce them. I see some similarity between the perspective that you typed out, and the perspective of the big three automakers in the 70s, "It cant be done" FULL STOP, and then putting blinders on to the people who are working to solve these issues. Granted, there are no guarantees that any of these technologies will pan out, but it is clear that we can no longer rely on fossil fuels as we use them, and we need to continue to press forward on developing technologies that will allow our children and their children to live on this planet without having to clean up an apocalyptic mess that we left for them.
I had an '86 Civic SI and it didn't use a catalytic. 30+ mpg. I also had an '85 HF. 50+ mpg. Interestingly, the gear ratio for the SI in 5th was the same as the HF in 3rd.
I guess this is what happens when companies are controlled by finance guys instead of engineers? Too worried about short term profits instead of long time viability.
One of the things you forgot to look at with the EPA results was the rear differential ratio. 3.08 vs 2.7 means that the stock motor was making 12.3% less engine rpm vs the Honda motor, for the same speed. This also affects the dynamic compression ratio, allowing the fuel to burn more completely because the piston stays at the top of the combustion chamber a bit longer, building more pressure before pushing the piston down the bore.
A CVCC Impala 350 might have been better from a driveability (stall resistant, starts when cold, no hesitation) standpoint than the normal Impala. Also, the cost of manufacturing it had to be less with the CVCC version, since you got to skip cat convertors, EGR, and smog pumps, less parts !! Reliability without all those weird things hanging off the engine would be up too, so, on balance, the CVCC won out. Maintenance headaches down too with CVCC. Add CVCC to microprocessor controls & fuel injection, and then maybe build a 3 or 4 Liter V8 made from 2 Honda 4 cylinder heads (new block and crank obviously), and then you really had a winner.
I'm a mechanical engineer. As you were mentioning the letter to the Academy of Sciences, I heard a previous boss' voice reading the letter as if he wrote it. I have seen issues about money lead to lies like that.
11:46 - The CO2 output was higher. Well, you would expect that. Complete combustion of fuel in an engine results in CO2 and H2O (carbon dioxide and water). If you have more complete combustion, the HC and CO levels are going to go down, and the CO2 is going to go up. 13:46 - "GM was lying to the public" - they weren't lying. They just said they didn't think the technology would work. If that's what they thought, that's what they thought. They didn't research it fully, so they said they thought it wouldn't work. But they're not "lying". Someone isn't lying if they don't actually know something. They would be lying if they tried out the technology, got it to work, and then said it didn't work. But that isn't what they did. It is pretty clear from your last statement, that you "love a good story that embarrasses GM", that you hate GM. Why do you hate GM? Why does anyone hate GM, for that matter? So they didn't do as good a job, and things obviously ultimately didn't work out as well for them. Why would that make you, or anyone, happy? Personally I think what happened to our auto industry is terrible. The competition outdid them. I don't think it's something to be happy about. WE invented cars. Japan didn't. WE were the innovators going back through history. So, our auto industry failing, and all of our manufacturing ability that we once had that went out of this country and is now practically non-existent, is something to be happy about?
I remember the Honda CVCC very well. It was a pre-combustion chamber stratified charge design. It had a small pre chamber that had an extremely rich mix in it and a very lean mix in the main chamber. On paper it worked pretty well but that's on paper. The problem with the pre chamber design is that the combustion event takes way too long. What Honda had to do is they had to retard the timing and limit the advance. Basically the initial timing on their engines ran around top dead center with a total advance of less than 30° at 2,000 RPM. The engine was a 1500 cc engine and believe it or not the 1200 with a standard hemi head combustion chamber could actually outrun it. The very low advanced curve severely hurt power production and fuel economy. After 1980 Honda had to put a catalytic converter on to the vehicle so has to tune the engine with much better fuel mixes in advance curves and yes a 1980 Civic with the same engine could achieve 50 miles per gallon with a 5-speed manual. Previously they could not even achieve 40. You made a comment about carbon dioxide and carbon monoxide. Carbon monoxide must be limited to as close to zero as possible because it is a deadly dangerous poison. It is a poisonous gas it will kill its victim the reason why is it's one part carbon to one part oxygen. It will rob it's victim of any Oxygen in order to complete itself by having two parts oxygen to one part carbon. That is what carbon dioxide is. It is two parts oxygen to one part carbon. It is the result of complete combustion of any type of fuel. Carbon monoxide is a result of incomplete combustion. Carbon dioxide is not a deadly dangerous gas nor is it a heat trapping gas. You cannot eliminate carbon dioxide because you're breathing carbon dioxide out when you breathe in O2. All living things on this planet except plants breathe in O2 and breathe out CO2. The chemical composition of carbon dioxide is the same whether it comes from respiration or combustion. Complete combustion should only produce carbon dioxide and water vapor. That is considered a pollution free engine.
This really helps me understand how the CVCC engine had lower MPG with so much better combustion gas numbers. I thought it must have to do with ignition timing and heat loss to coolant.
MAJOR APOLOGY: In the video I erroneously said during the development of the CVCC Honda was developing it's first 4-stroke engine. That is wrong (as many of you pointed out). I script/outline videos and during my research on this I obviously mis-typed something and didn't catch it in editing.
They actually built a Formula 1 race engine in the mid 60's and probably previously mentioned came out in the US in the Civic the 1200 ALL Aluminum engine.(The CVCC's had a cast Iron Block) a MUCH better engine.
Pin this at the top. Nobody is perfect!
Everyone makes a mistake. I don’t see how you don’t miss more. Your video was still really interesting and informative. I worked in the motorcycle division for over 20 years, HONDA history is sort of my “thing”.
@@ronstucker3550 their RA273 was designed by the legendary Shoichiro Irimajiri (lead designer and engineer on the iconic RC166 and HONDA CBX). Read the story of the RC166 for some fascinating insight into how far ahead HONDA was in engine technology. HONDA even built their own gearboxes, probably because they had extensive engineering experience from their motorcycle division. It needs to be noted that much of the FI technology originated from the motorcycle division. HONDA also built the RC116 which holds the record for the highest power output for a N/A engine. The RC116 produced 321.5 horsepower per liter. It was a 49.77cc twin that produced 16 horsepower at 21,500 RPM. This was in 1966! Even Modern MotoGP engines don’t even come close to this output per liter.
@@mlynch001 Knowing by working on these early Honda engines From the late 60's 600's to the 1800's mid 80's engines and all in between.( I owned 2 1st gen 1981 Accords ) both Sticks They were one of the best most reliable cars I ever owned. Also rode bikes built in Japan from my early teens to late 20's (Harley's after that) I knew all the history of their F-1 engine program back in the 60's. In late 80+ CVCC's with the 4 exaust ports instead if the (2 port early 80- 75 heads) became the most reliable. Only problem was those Damn carbs.
This may interest you: there was large unintended engineering mistake made by the big three as they entered the smog era in the early 1970's. One of the ways American engines changed as you mentioned was to reduce the compression. That in itself was not a bad idea - but the way most American car companies did that was to slightly drop the top height of the piston. This dramatic increase in the quench height was a disaster for power and fuel mileage, and for drivability and emissions. It is much better understood now how important it is to have a tighter piston to cylinder head measurement, especially on wedge shaped combustion chambers. A closer quench height reduces emissions, while increasing power and fuel mileage. There is more to it than my simple explanation, but the science of what happens in the combustion chamber was still an elusive topic in the 1970's.
But doesn't high compression require high octane fuel which is more expensive?
@@MisterMikeTexas You are misunderstanding what quench is: on a wedge shaped combustion chamber the valves are typically on one side, and then there is a flat portion on the other side. Quench is the distance from the flat part of the cylinder head to the top of the piston. You can actually have a low compression ratio and a tight quench all at the same time. The compression ratio is determined by the size of the combustion chamber in relation to the volume of the cylinder. Quench has no bearing on needing premium or regular fuel. Quench does affect mixture motion - tight quench OHV engines burn cleaner and more powerfully. What many of the big 3 engineers did to reduce the compression ration was to change the piston pin height by .020" to .050". This was also the reason why many of these engines had horrible dieseling problems where they would keep running after the ignition was turned off - the extra quench distance often filled up with carbon deposits that would act as a secondary ignition source.
@@dangraff8467 Leaded gas was not necessary for high compression - its use was as a valve lubricant and sealer, Newer engines have hardened valve seats and other design features that live just fine even at high compression ratios without needing lead.
@@Thomas63r2 My 78 Fairmont would "diesel" at times. Worse than Clark Griswald's Family Truckster. Thanks for the info.
@@MisterMikeTexas It seems funny now, but I can still remember people shutting off their car, getting out and going into their house - and their car would still be sputtering and dieseling on! We blamed it on emissions equipment, which was only partially correct. It probably wasn't for another decade before many people/engineers understood excess quench distance as the cause.
By meeting EPA standards *without* a catalytic converter, Honda likely realized significant savings on per unit material costs. Subsequent success of Honda as an automotive manufacturer suggests that they made sound engineering decisions.
On the subject of the Impala retrofit: I'm guessing that a properly engineered CVCC system for a Chevy 350 would have taken a tremendous amount of development, but may have produced better performance. I speculate that the only reason Honda did this was to promote the possibility of GM licensing CVCC technology. Anyone who was familiar with GM engineers at the time knows that they suffered from severe "not invented here" syndrome; this was never going to happen.
My dad was an engineer for GM in the late 60s and early 70s and quite the forward-thinking person. GM being stuck in the mud of their own choices is why he left after they refused to listen to what he said about the THM200 being a POS.
That and if Honda can get the EPA to enforce standards that only Honda can meet, then it gives them a very unfair advantage going forward.
@@tsherwoodrzeroand the vanity of leadership and inability to receive criticism kills companies’ success to this day
I'm a chemist and it's fascinating to see the shift in the gases emitted, especially in the changes in carbon monoxide and carbon dioxide. These two gases are related to each other in something called the Boudouard reaction, and their admixture can be affected by the temperature in which they are formed. Any data related to engine heat management would be very interesting.
I know only the basics (and my wife is a chemistry teacher and I have an engineering background); however that was far beyond the scope of this video! :)
I can't offer data but better emissions and more power is why today's cars engines operate at high temperatures. In the 60's a 180 degree thermostat was considered 'hot' while today many cars run 190 degree thermostats as standard.
I will give you a clue: the higher the NOx emissions, the higher the combustion temperatures.
The higher CO2 emissions meant more complete combustion, right? That's why I can't figure out why the MPG was less on the CVCC.
Carbon monoxide and carbon dioxide are related to each other. One is an extremely deadly poisonous gas, the other is a life-giving gas. Carbon monoxide is one part carbon to one part oxygen it kills its victim by robbing its body of any Oxygen it can Rob so as to be carbon dioxide rather than monoxide. No amount of carbon monoxide is safe. It is the result of incomplete combustion of either carbohydrate fuel or hydrocarbon fuel.
Carbon dioxide on the other hand is two parts oxygen to one part carbon regardless of whether it comes from respiration or combustion. It is a naturally occurring gas. All living things that are not a plant breathe in O2 and breathe out CO2. Plants do the reverse they absorb CO2 sequester the carbon and release the oxygen. Without this process no life could exist on this planet. Carbon monoxide is a deadly dangerous pollutant whereas carbon dioxide is a naturally occurring gas that gives life to the planet. It is not a deadly dangerous pollutant. It has no effect on the atmosphere or the climate.
I had a CVCC in an Accord and Civic one of best engines I've ever had. SUPER Simple, Reliable and Insane MPG too bad the chassis rusted out...
Glad to know that I m not the only one who had the rust issues on my cvcc but the mileage was truly impressive.
@@russellstewart5414 How many years did you get out of it before it rusted out?
Im currently restoring a 78 honda civic cvcc!
@@russellstewart5414 my fathers cvcc had over 400k
Thanks for this, never knew about or heard this story. Growing up during the 1970’s, American car manufacturers didn’t seem to take the Japanese auto makers seriously and for the most part not many American car buyers either. They were considered ‘novelties’, toy cars and can even recall some friends of family going as far as calling them ‘tuna/sardine cans’, and jokingly mocked them compared to ‘REAL’ American cars! Oh I’m sure the Japanese manufacturers were quite well aware of this and throughout the 70’s and 80’s, stopped at nothing to change all those perceptions and misconceptions. Fast forward to the 1990’s and later some of the greatest small performance cars are from Japan, and while the American Auto makers are in a mad scramble to go FULL EV, again, Japanese manufacturers know it’s not the answer - just yet, and opt to go with PHEV’s and a few BEV’s just to say they have them on the market and ‘appease’ markets and regulatory demands for them. But ultimately, where the big three dominated the industry, it was their shortsightedness, and stubborn arrogance that led to the makers of rinky-dink, toy cars to dominate the auto industry and most American roads and highways today!
Heh...for the last 35 years I've been driving one of the cars that pretty much started it all...1968 Toyota Corolla.
It just keeps going.
@@yourhandlehere1 That’s nonsense. While the Japanese may produce significantly higher quality drivetrains due to a cultural proclivity for attention to detail, etc. They don’t have any magic dust that they can sprinkle into an engine or transmission to make it last forever.
@@markteague8889 Well gee Mark...I drove that 55 year old "nonsense" to the store for coffee this morning. Didn't need a tow truck or anything.
@@yourhandlehere1 How many miles are on the drive train? What service has been done to it over the course of its life? Did it spew magic “lasts forever” dust from the exhaust all the way there and back?!? 😁
@@markteague8889 Are you asking if cars and engines require maintenance? Yes, they do. Regular (frequent) oil changes, good filters, grease in all the fittings, fluids kept up.
It's currently showing about 75,000 miles again...I've lost track of how many times it's rolled over.
Really sorry if you decided to buy a Dodge or something.
Early in my career as a mechanic, I worked on several CVCC engines. Aluminum head on a cast iron block had issues blowing the gasket if they were overheated. The small CVCC pre-chamber was prone to carbon/coking up, significantly affecting performance. The chambers were also a challenge to pull out of the head casting and completely clean during a rebuild on the head/valve job. Amazing change once it was all back together and flowing air/fuel correctly and all 3 valves were reconditioned. The pre-chamber valve head was about 12 mm/1/2" in diameter and the hole into the main chamber was 6-7 mm. Usually restricted with higher mileage. Later version had two holes to create more vortices. Great engine, but not without some issues.
If I remember right, they had a habit of blowing the head gasket between #2 and #3 due to the heat.
Honda has never used an iron engine block in their cars.
volvo was early In 1978, the Volvo 240 earned the recognition as the USA's Cleanest Car from the California Air Resources Board. In 1976 Volvo Cars presented a world first in the environmental area - the three-way catalytic converter with Lambda sensor for exhaust emission control. "The most significant breakthrough ever made in the control of vehicle exhaust emissions”. So said Tom Quinn, chairman of the California Air Resources Board (CARB), when the 1977 model of the Volvo 244 equipped with a Lambda sensor system was launched on the American market in the autumn of 1976,
Yes, and Bosch mechanical (not electronic) fuel injection that worked off of an air flow plate and fuel pressure sensor.
And you want all that in a car that looks like the box it came in?
@@67marlinsBEST CAR EVER BUILT!!
@@mjg263 Nope, sorry, the 140 series was the best. 240, 740, was refinement of, the best car ever. (Relative to it’s time)
@mjg263 Unless it went further than our 1977 Ford LTD II at 532,000 miles on the original engine, no it isn't.
People admired the Ford for its reliability and styling......no one would ever make that comment about a volvo.
Interesting thing with the fuel economy. If you look at the bottom of the page where it says NOTE: the modified Honda Car had a different axle ratio of 3.08 compared to the Stock 2.73. Axle ratios directly affect fuel economy so that aspect of the test isn't accurately represented.
Edit: and in other terms of this test, due to how chemisty works you will always have byproducts of a chemical reaction, you have a significant decrease in HC or hydrocarbons (aka unburnt fuel) and a decrease in CO (carbon monixide) which both occur due to an inefficent combustion (due to lack of Oxygen, or too much fuel) the increase in NOx and CO2 are due to an increase in combustion efficiency.
I would expect higher milage out of a 2.73 rear end than a 3.08 rear end, so the 3.08 was at a disadvantage.
Fascinating story... and I did know about it. My first car was a CVCC (possibly an SB-1) and it effected my opinion of every car I owned, afterward. Insane fuel economy at a time when gas was not cheap. Better, is was light and fast with the impressive practicality of being a hatchback. The auto world could really use Mr Honda's kind of thinking, today.
Amen brother. Honda seems to have lost the innovative edge that it once had. They are still improving incrementally but no longer the leader they once were when the founder was still setting the agenda.
what do you think Musk is doing with Tesla, same thing.
@@seancollins9745 Far more. EVs represent a paradigm shit toward sustainable transportation.
@@deanrhodenizer938 what makes ice cars not sustainable? We're not exactly running out of oil, and modern engines run clean. In fact, EVs are not sustainable, especially for the masses.
@@deeplyclosetedindividual They use fossil fuels... Yea, it will take some time to burn it all but the time will come when it is all gone, and... we really need those hydrocarbons for the petrochemical industry.
Fascinating story - I didn't know about this. One point of contention: I see this all the time when people compare fuel economy, where they say something like "1 MPG is a small difference". Whether that is true or not depends on the size of the number. For the CVCC vs. Stock at 45 MPH, the difference is 24%! That's huge.
at the same time: Honda retrofitted their tech on GMs car in very short order, there is no reason to assume that it could not have been improved over time.
@@uliwehner there is absolute proof. The Honda motor company itself ABANDONED cvcc technology eventually and that is more than enough proof that it wouldn't have ever worked right on a 350 Chevy engine. In 1979 when Honda increased the size of the engine a mere 9 cubic inches they had to use a catalytic converter to meet emissions.
@@crazyoilfieldmechanic3195 you mean millions of cars sold later? they even used carburetors back in the day. things evolve, especially in technology.
My 1983 Honda civic si traveling 90 mph getting 37 mpg, was the best highway vehicle I ever had. Yes I was speeding, it was very stable on the road.
My buddy picked up a 1964 Malibu with the straight six in the mid 80’s. For kicks they did an emission test on it and punched in that it was an 87 Chevy (Corsica I think). It passed.
Great story I never heard about! Thanks, Jon. The CVCC was superior engineering for small 4 cylinder engines that were way more fuel efficient compared to the large V-8's most American cars were running. The higher fuel usage CVCC created was hardly noticed on a small 4 cylinder fuel sipper - on a V-8, the lower mileage was dramatic. The GM Chairman's condescending answer to a press question addressing CVCC was par for GM at that time, even though apparent from the later EPA test results he WAS telling the truth. I think GM had probably tested and tried the CVCC system for themselves. Mr. Gerstenberg was no engineer - I think he was a finance guy - but GM certainly had the resources to investigate the Honda system and most probably did.
The other thing was that the Big Three, including GM were jointly lobbying the EPA at this same time telling them that the emissions standards couldn't be met because they were loath to spend the billions it was going to take to meet them. Once the federal government dug in their heels and said the automakers had no choice - GM invented the catalytic converter and preserved the V-8's Americans loved and wanted to buy. The emissions standards were met, all the air pumps and add-ons went away and cars ran better and got better mileage to boot. The GM developed catalytic converter technology went into use industry-wide and is still used today. Even by Honda. If Mr. Gerstenburg made any mistakes; it was being arrogant in his dealings with the press and dishonest about GM's ability to meet the standards, (which they quickly did.) GM has always had engineering resources like no-one else in the business. Unfortunately, they've also had more than their share of short-sighted executives who couldn't see past the next quarterly earnings statement making the big product decisions. Honda, being much smaller and less hidebound, usually allowed the engineering cream to rise to the top and fostered a well-deserved image of a scrappy, creative company producing great products.
Great comment and additional history.
As I recall, their lobbying worked to get the standards delayed; I want to say the President put the standards off for 2 years?
I'd have to go back and look at that again.
very good summary:better than my commnt above !
Dunno where you get the idea that air pumps and other add ons went away with the advent of the catalytic converter . Many cars still used air pumps , and all still used an EGR valve and other stuff .
Yep, GM was being run by people who had no real engineering or production experience but they thought they were great managers because they were making a good profit today. So down the road they "managed" to turn what was once a "blue chip stock" company into bankruptcy because of that. A problem we still have today all across corporate America where people believe that management is only about managing and no experience with what they're doing is necessary.
@@HowardJrFord Due to tightening emissions standards that became necessary. And complex. And expensive.
at the bottom of that epa test result for the impala it states that the stock impala had a higher rear end ratio than the cvcc, that would have significantly affected the results for the fuel economy
As would power to weight ratio, power curve of the engine, drag coefficient, transmission loss, rolling friction, etc, etc. Axle ratio is a factor but in no way directly comparable.
Yeah even identical cars with just a ratio change would make a big difference, my car came with a 3.08:1 diff, i put a 3.46:1 diff in, fuel economy went from 830km to 60ltrs freeway driving, to 620km/60ltrs
City driving got better, if im in traffic and things, economy went from 500km to 600. So its a big deal. Not to mention untested things like tyre pressure, the ambient temperature of the day, the fuel used, lubricant oil level etc
Good catch! That 2.73 in the stock 350 would have been MUCH better on fuel economy than the 3.08 on the CVCC, especially since they were testing on a rolling road dyno. No weight, drag or other factors to skew it. I don't know the math, but someone out there in Internet land could probably calculate the difference in engine RPM. I wonder if they even had the same tranny...?
@mojoxerspootykat594 at 60 mph 2.73 would be ~2062rpm 3.08 would be ~2327rpm, so about 13% higher rpm for the cvcc engine. The cvcc engine got roughly 13% worse fuel mileage at 60, however the rate that fuel economy diminishes with rpm increases is not linear, and it would probably do better than a 13% increase in economy with the reduced rpm.
@@jameswolfe8065 you believe a stock 350 emission motor actually got 19mpg? Maybe 15mpg I might believe. Most 350s I have driven got 12 to 14mpg. But manufacturers exaggerated back then or cheated the system.
What caught my eye was the 3.08 axle on the CVCC car vs the 2.73 axle on the stock 350. I was driving a fuel delivery tanker during that season of 1973-4 and I recall the manipulated and manufactured “fuel crisis.” I also recall a short seminar showing a full dozen add-on emission systems on the new 1974 Fords, turning the cars into total dogs.
Exactly! The lower gears on the CVCC Impala mean it’s running higher RPM at every speed
@@MrJeffcoley1 which means the CVCC was at a disadvantage.
@@SockyNoob but the CCVC engine may have put out less power, which then necessitated the lower gearing.
I saw that as well. I currently own 2 Grand Marquis; one is a 1995 with a 3.08 and the other is a 1996 with a 2.73. In my experience, that is good for about 2 mpg. Sharp eye dude!
@@Adamroable The video didn’t say anything about Honda changing the drivetrain, 3.08 and 2.73 were both available options. My assumption is that’s just what the dealer had available
I think Honda learned something valuable here as well---there is no "one size fits all" approach to tech, instead it needs to vary by application
I know for a fact (friend was a NYC employed mechanic) assigned to the NYC Police Dept.from the early 70's till he retired in the early 2010's. I was a foreign auto mechanic at the time specializing in Japanese cars Toyota, Datsun and Honda. My friend in early 1974 came to me to tell me that there was a 74 Chevy Impala (RMP) assigned to the PCT that had HONDA parts installed on it and it was a test car for Air Pollution. He at the time worked at the 122nd Pct Staten Island N.Y.
woW
Great post. My father had a 1973 Impala new. I remember sometime between 1975 and 1979 he had to remove the air pump because the car was running like garbage. There it sat in the shed next to my bicycle until he purchased a new 1979 Bronco and threw the air pump in the trunk to trade the car in. I believe the air pumps were a cheap way to dilute the exhaust emmisions, allowing the old motors to keep being used. Wouldn't the same dilution happen after the exhaust mixed with environment? Just a PPM altering device that helped nothing.
The air injection pump was used to introduce oxygen near the exhaust valve to promote burning leftover fuel.
@@markg7030 Guessing it didn't work.
@@MJorgy5 It worked fine, but added a bunch of extra components to go bad. Once computers and FI came along, most, but not all, cars abandoned it.
It wasn't just diluting the exhaust. It was a cheap way to reduce HC and CO emissions by burning them off in the exhaust manifold with extra oxygen. It's been used in more recent times on some engines as well to reduce cold start emissions before the converter warms up, though it was generally a band aid to get an old engine design to pass new emissions standards for a bit longer without a more significant redesign.
@@61rampy65 I am wanting to say the last car I owned with an AIR pump was a 1991 Ford LTD. I don't think any of my current cars have it. (1995 and 1996)
They started selling Honda cars in my hometown in 1974. My dad went and looked at a Honda CVCC and liked how it drove. He didn't buy it; instead he bought a Maverick. Honda used to advertise the fact their cars were able to operate without a catalytic converter, I believe, until maybe 1977; some time after other manufacturers had started using them. While they had that CVCC engine, at the time we looked at buying one, they didn't offer a fully automatic transmission. I think it was called "Hondamatic." You shifted, but there was no clutch. Great video!
I had and worked on an 83 Civic, which had the ASCC system, which was a further development of CVCC. It did have a lot of vacuum lines, but they were mostly easy to get to. An 88 Wrangler that I had later was a complete spiderweb of hoses.
I had an 87 RX-7 and 88 RX-7 turbo 2, and I still have nightmares about the rats nets of vacuum lines under the hood.
Quite a fascinating story Jon. There are several reasons why the results are as they are. Firstly it looks like the CCVC engine is running a lot leaner than the stock Chevy - you can tell this by the low CO/HC and higher NOx. Any engine will demonstrate this trade-off. What the CCVC does is allow lean mixtures to be reliably ignited compared with (then) conventional combustion chambers allowing good combustion stability and running smoothness. Where it loses to a conventional combustion chamber is in two areas - increasing surface/volume ratio and increased pumping work - i.e. the energy loss of the gas moving from the prechamber to the main chamber during combustion and expansion. Having the relatively large fraction of combustion gas flow at high speed through the throat connecting the prechamber to the main chamber also increases heat loss to the cylinder head which, along with the higher overall chamber surface area means the waste heat to the cylinder head and cooling circuit causes greater fuel consumption/poorer "gas" mileage. (nb: don't confuse gas with "gas"...). Interestingly I don't think Honda would have spent a fortune developing a one-off demonstrator so chances are high that the system developed for the Impala and Vega could have been substantially improved in all aspects. I suspect that the additional costs of extra valves, more complex carburettors etc wouldn't have won over the beancounters though and this may have been what reduced its widespread adoption. Also interesting is that this style of pre-chamber combustion system has made a resurgence via F1 into production cars (noteably the Maseratic MC20 so far) where a small prechamber (passively filled in the case of the MC20) is ignited to create a high velocity "jet" ignition source in the main chamber. Mahle are proponents of this system and you can see their promotional video here: th-cam.com/video/n6Eutw0WU3U/w-d-xo.html
Thank you. I had heard this story over the years and it never changed. I heard that it was the head change only and it made more power and the MPG jumped by over 25% increase. Thank you for the rest of the story.
You're very welcome
The cvcc system, in paper seems simple. Have you ever worked on one?
That carburetor was a nightmare, with all those vacuum hoses. I forget a lot of things. Not what pain in the butt ALL of the mid 1970's and later carbureted engines. Honda in time dropped it and adopted fuel injection and a nice system to boot!
The CVCC was no fun to work on, but they were tough little motors and ran forever! By the time Honda brought out the PGM-FI their motors were incredible! In fact I think the late 80's early 90's saw the best motors to ever come from them.
@@christopher88719
Indeed!
I think a lot of manufacturers had their best engines in the late 80's and 90's. Down in power by today's standards but a lot more reliable and easier to live with!
it took time to sift through all the vacuum hoses I agree.
I wish it were more obvious when you got the throttle plates in proper relation.
All 70s and 80s smog carbs were a nightmare. However, Honda had significantly more vaccuum operated gizmos.
@@christopher88719 PGM-FI is actually still used on their motorcycles to this day
15-20% more fuel use at most speeds isn’t “slightly worse”.
at 20 mpg, which would've been pretty good in early 70s; 20% is 4 mpg. 16 vs 20. Slightly worse is mostly appropriate vs 20% at 60 mpg 48 vs 60; but if you were getting 50, you'd not be complaining.
To have the numbers mean anything, they have to be bigger. if you make 100k a year, a 20% pay cut is a huge 20k or around 400/wk. If you make 15k a year and get a 20% pay raise is around 50/wk.
In the end, how people drive and think about driving would make the biggest difference.
I drove a 75 Pontiac that no matter how gentle you drive, would get 9 mpg. 20 would be heaven in that thing.
Ford developed "lean" burn engines in the 1990's and they were actually sold until the EPA decided that they created to much NOx. The fuel mileage was impressive in some cases with 6 cylinder engines improving fuel mileage over regular 4 cylinder engines. Interestingly GM had a few years of lean burn engines in the Corvette in Australia as well. Those cars were known for good performance and improved fuel mileage. It's interesting that stratified and homogenized mixtures/cycles are still being studied for direct fuel injection as well.
Corvettes were NEVER sold in Australia.
Many six cylinder engines use less fuel than gas guzzling 4s!!
@@ldnwholesale8552 C1,2,3 Corvettes *were* sold in Australia. Sales to the Australian market ended in 1978 before resuming with the C8 in 2020.
Ford in Europe introduced 1.4 & 1.6 lean burn cvh engine around 1986 Europe, I think there might have been more lean burn engines from ford Europe but I can't remember
What Corvette?
Gm or Holden never sold a corvette here in Australia.
I think Honda had some lean CVCC engines during the 1980s. There were a few that had a wideband O2 sensor.
Fast forward to 10ish yrs ago.
Can you imagine how the Japanese engineers were ripping their hair out,trying to figure out how VW could make a diesel pass emissions and they couldn't?
They wanted in the small diesel market really bad at that time, that really had to have them fit to be tied.
I was a Mercedes Benz technician at the time and I couldn't figure out how VW didn't need DEF but MB did. Once the truth came out it all made sense.
My mother has a Saturn Vue that partly came from that Japanese diesel program. Honda bought GM diesel engines for the European market and GM got Honda 3.5L gas V6s and 5-speed transaxles that went into the Saturn Vue. The V6 model has a big J-shaped air intake plenum that makes it obvious the engine wasn't designed for that chassis. But that smooth 250hp V6 is easily the best part of the car.
I was considering a diesel Jetta back then. I would only consider a no DEF engine. I would have been so angry if I had been duped by VW's fraud.
@@skylinefever it actually worked out really well for the customers. I bought a Golf TDI, owned it for 2 years, then sold it back to VW for more than I paid for it.
I can say, without a doubt, for … “reasons”… that I can 110% confirm they were going crazy trying to figure out how they did it. Until they knew.
I have been wondering when someone would put a spotlight on this story that I have known about for decades. I am quite surprised that a movie has not been made about this, like the movie "Tucker", or "Flash of Genius". Thanks for putting this out!
@george9417 Yes, it's known as a "hegelian dialectec" (create problem, pretend to have solution) that restricts people's freedoms in allowing real innovative products to come to the marketplace, that will vastly improve the quality of life for the majority of people. Yeah we are "bootlickers" using out Federal Reserve Notes to transact business in the establishment , run by the individuals that the seal on the reverse of the US $1 bill depicts!
Well put. I subscribed... & am looking forward to whatever else you've done. Remembering with wife's 1st car, the civic, turning on AC ment needing to downshift to 3rd... they've come a long way.
My Audi had the same problem, turning the AC on was like hitting a wall of marshmallows, in those days Audi bought its A/Cs from GM, when the Japanese got their own compressors, the result was about half the weight and half the power consumption of the GM units The GM units were fine if you had a big V8 and didn't care about gas mileage. Nobody uses the GM designed compressors anymore and GM no longer makes refrigerators, selling that business as well.
Same thing with my old '88 Hyundai Excel. Had to turn off the a/c to pass..lol
The irony of the emission standards and greenhouse gas emissions is that as you reduce exhaust gas content for HC & CO you increase CO2. So it makes perfect sense that the CVCC produced more CO2. This is addressed with FI & O2 monitoring which cycles the exhaust alternately from rich to lean to activate the oxidization and reduction beds in the catalytic converter.
Yep. When you properly burn the HC, it becomes CO2.
SO happy to see your hard work is gaining some traction. Congrats Jon! Awesome story telling as always.
Thanks so much! Means a lot hearing from you!
Hi Jon, good video! I am 63 years old and have been a automobile mechanic most of my life. It's not the emission control(s) that rob the horsepower, it's the lean air/fuel mixture that takes away power and good drivability. The EGR "exhaust gas recirculation" valve is to cool the combustion chamber so the engine can run lean with unleaded fuel. Please reply. Dave...
If nothing else the overall quality of any Honda puts any GM to shame. I've owned both and know it all too well. The most I could get out of any Chevy was 115K miles before the timing chain gear lost all the plastic. I put 216K miles on an Acura and didn't change anything but brakes, wiper blades, tires and a battery.... plus it got 36 mpg.
Yes, 3.8 V6 had Teflon coated timing sprocket. The engine was good for 90,000 miles. I knew this, but the 3.8 V6 was a great engine.
I bought an '87 Olds 88 f.w.d. with a junk yard engine. I replaced the timing sprocket, and got 200,000 mi. The engine was good when I junked it.
you talk crap about a chevys timing sprocket at 115k, yet fail to mention the timing belt on your acura probably looked like the ground at desert valley.
@@frigglebiscuit7484 Please check my response. I was talking from experience about a timing sprocket on an Olds 3.8 L. V6, not a Chevy 350 C.I.
@@frigglebiscuit7484 The Acura RSX-S doesn't have a timing belt.
Those variances partly came from the different rear end ratios. The Honda 350 was running a shorter gearing which means the engine would have ran at higher rpms comparable to the normal engine. That may not account for all of the discrepancy shown in emissions and fuel economy, but it would have an impact.
I owned a '73 Impala....great back seat.
my dad bought a 77 Honda Civic but it didnt have the CVCC. at least it didnt have the badging. the engine was a 1,230 something cc displacement. with a 4-speed manual, and driving it conservatively it still only ever got 25mpg.
fun car nontheless
Soichiro Honda built very few 2 cycle engines compared to how many were 4 strokes. Just about everything Honda built was 4 cycle, motorcycles and cars.
He actually said once "Honda will never build a two stroke." Course, that was right before they built the CR250 Elsinore
"Stroke's the word" - Billy Squire 😁
Agreed, he despised 2 strokes only adopting them later as rules in motorcycle competition restricted the number of cylinders allowable.
Back then two-strokes didn't last long in comparison to 4-strokes, and Sochiro was OCD about making the best possible products he could so that his customers got the best value possible. It wasn't the most profitable approach, only the best one. Too bad nobody else has followed him.
Really curious if you noticed the rear end gear difference in the 350 testing vehicles. It looks like they attempted to adjust the dyno to match but the CVCC engine would still be running at a higher rpm at all measured speeds. Interesting comparison and seems like the Impala and Vega stories have been melded together over time.
I have worked on those Honda heads. They had a problem with the auxiliary valves getting carbon deposits built up on them. Sometimes it was so bad that the passage was completely closed off. Those engines were also covered with vacuum hoses.
18 mpg for an Impala with a 350 is pretty good. But an apples to apples test would have been a '75 Impala with a 350 after it received both the EGR and Catalytic converter. I remember these cars struggling to get 14 mpg. We had a new Camaro with a 305 in '76 and 18 mpg was the norm. Also did you notice the difference in the rear end ratio? That would have made a noticeable difference in mileage as well. I get that they were testing what was being built at the time but in actuality the CVCC system would have gotten better mileage while also producing less emissions than a truly comparable 350 engine with the aforementioned controls. Cool video though, those were dark times that have never really gone completely away.
The CVCC motor was one of the best ever made. Shame it couldn’t still be in production
Had some friends back in university that had a Honda with that engine. That was one tough car, it got by on poor maintenance and hard usage. I don't remember them ever having trouble with it or saying a bad word about it. Meanwhile I was driving a Buick hand-me-down from my aunt and uncle that couldn't go 10 miles without breaking. Car was lowish in miles and my Uncle had babied it so it wasn't just that it was worn out. Was a happy day when I saw the back end of that car going down the road.
better engines came to replace it.
I bought a 1980 CIVIV w/CVCC in 1983 as my college car. It lasted until 2003, with over 220,000 miles. The engine was solid, I never had engine problems, or fuel system issues (carburetor). I changed the oil every 3,000 miles, and that was it! Likewise, I never had transmission problems, other than two clutch plates replaced.
It might have remained in production longer if an EFI variant was built. Japan had an EFI CVCC engine, it was in the Honda Bulldog Turbo.
Those had a 1.2L turbo engine, but I suppose it could have been applied to the largest NA CVCC engine.
If there was a need to make a more powerful Honda, they could have applied the turbo to larger CVCC engines. The reason Japan got some extra small engines was because cars were often taxed by engine displacement. That also motivated Japanese car companies to build forced induction engines. The displacement tax is why their Datsun Z-car (Nissan Fairlady Z S30/S130) often had 2.0L engines.
@@skylinefever I think moving to 4 valves per cylinder is more the case. the EW which probably had the final iteration of CVCC forgoes an extra exhaust valve for the CVCC chamber. It would have been interesting to see further developments. An also Japan only fuel injected EW with CVCC made 110ps. Seems pretty alright for a 1.5 although more powerful engines like the d15b would come later with more modern head designs
Honda cvcc engines didn't last very long though. They failed to mention this. They went through heads quickly and were very expensive to repair. I always avoided them when looking for used cars back then.
I've also heard that the CVCC engines were prone to carbon deposits, which caused driveability and reliability issues. Regardless, this is fascinating. I always enjoy stories of how the "little guy" beats a huge company at its own game.
I haven't seen a cvcc Honda since probably the late 80s on the road.
They rusted worse than any other car I've seen.
My uncle bought one ,and brand new it had surface rust at all the sheet metal bracing under the hood at the edges.
They started rusting on the way here on the boat.
@@MrTheHillfolk yes for sure. I live in a snow belt. Same here. The strut towers would literally break away from the fender. I used to see them pushing the hood up a bit sometimes. Lol
last time I saw my 300k miles cvcc engine.... car ran great up to that .
the head may have had a problem... not certain. I think the fuel leak near the carb was involved.
but honda had no parts for the repairs I wanted to do.
@@MrTheHillfolk oh man they were terrible rustbuckets. Great technology but dang, they did come off the boat with rust. Toyota too. We called corollas “corrodeds “.
I still have to wonder to this day, with results like that at 12:15, is it better to get more mileage out of a gallon of fuel, or is it better to use more fuel with cleaner tailpipe emissions?
I remember working on 6.4 Powerstrokes that were getting 8-9 MPG with a particulate filter, but 20-22 MPG when deleted, plus who knows what emissions emitted to produce the particulate filter system.
This is excellent. I have never heard this story either. Imagine that...GM acting like they were high and mighty. Well, ok, they were high and mighty at the time, but many of them also knew they were beginning to struggle.
In 1975 my wife went out and bought a Honda CVCC with Great gas mileage, lots of power, trouble-free. The price was outstanding! We ended up buying two others. Best cars ever built. Today we feel betrayed by Honda. At some point they priced themselves out of our price range. Today we are retired and on SSI and in need of a new car. SSI does not allow for things like the need of a new car so I'm driving my old 99 Olds van and my 99 Ford F-250! Bring back the CVCC!!
2006 Honda Accord with the 2.4L, the K series engine are great engines. i believe the VTEC system replace the CVCC system.
@@crazeguy26 In the late 80s, there were no VTEC engines, but Honda ended the CVCC. I think they decided to use EFI and stop making CVCC engines.
Not that they couldn't make an EFI CVCC engine, the Japan-only Honda Bulldog had an EFI CVCC engine with a turbo.
what you have to remember is the drivetrain alone in a 73 chevy weighs more than the whole honda cars at that time.
A fully dressed 350 Chhevrolet with the usual automatic trans weighs around 800 pounds. The Honda civic was around 1600 pounds.
@@camillosteuss no, you misunderstand. I meant a fully dressed Chevrolet Engine and trans, not a whole assed car! Sorry about that!
@@camillosteuss and you are so right about Americans. Easy to spot as tourist in my land. And I prefer kilos, too. But a lot of this channel are from US I think, a d they have an aversion to metric measures.
@@suzi_mai damn, at least my common sense put me to correct conclusion that you meant the engine and trans... and i dont care about imp vs metric, i handle both, im a machinist, so that shit is all over the place and nothing unusual to me... hell, i even mix them and match them depending on work i am doing... and welding, 1mm is 40 amps, but 40 thou is 40 amps, so you know that any sheet of steel i see i instantly convert from mm that is my default reference into thou of an inch...
Even before Honda was experimenting with this, There was the Texaco combustion process in the late 50s/early 60s where a 430 ci Lincoln engine got amazing fuel economy but had one issue, it had to be driven in order to get it warm enough for the heater to work. The combustion was a stratified charge system so in low load, low rpm running the combustion was a ball that never reached the cylinder walls. This I believe is what evolved into the Ford PorCo system.
The Texaco TCCS engine was more or less a spark-assisted diesel engine running on gasoline. Or, to be correct, it used some kind of kerosene. TCCS did not require high octane or high cetane numbers for the fuel. Thus, fuel refining could be simplified. TCCS had a big drawback since it produced lot of smoke (and particulate matter at full load. Its power was "smoke limited", just as a diesel engine. Here Proco had an advantage, since it used premixed combustion at full load, via early injection. TCCS had "late" injection (near top dead center) and thus, there was not sufficient time available for mixing fuel and air to the molecular level, which is required for smoke-free combustion.
I just love the idea there’s fancy Honda Cylinder heads for a Chevy 350 somewhere out there.
I saw an article about this somewhere in my 70’s Motor Trend or Car Craft.
Always wondered about more info. Thanks.
Its called the LS lol
@@ChauncyFatsack Does "LS" stand for "like Sochiro's"? 🤣
Nah, proper CVCC heads have an extra valve & chamber for a rich fuel charge.
That’s what I thought was interesting for a set of 350 heads.
Hell, the spark plug on a CVCC head is tucked away in that rich mix chamber like an indirect diesel injector.
It’s a goofy setup and Honda went Madlad & put it on an American V8.
@@chaseman113 Soichiro Honda also ordered a 32-valve 4-stroke oval piston V4 engine be built for motorcycle grand prix racing after all! It was supposed to compete with two-stroke engines of the same capacity by revving twice as high (it was not a success!). Mad ideas were kind of his thing by the sounds of it, lol. 😊
my then-wife & I bought a '74 Civic CVCC. We loved it. Comfortable, roomy, good power & great handling. A friend I worked with (over 6') traded in his Vette for one because it was so much easier to get in & out of & was more comfortable.
Cool story! One thing though - Honda had stopped "only running two stroke engines" back about 1952. I do not recall Honda making ANY two strokes back in the '60s. The general consensus back then was that Honda HATED two strokes.
By the mid '60s, Honda was one of the world leaders in four stroke engine technology. Their first four stroke, the Dream E was released about 1952. They were the worlds largest motorcycle manufacturer by 1959, most (if not all) four strokes. By the mid '60s they were winning world motorcycle GP races with their 17,000 RPM four and six cylinder four stroke engines, competing against the two strokes. They were also racing F1 with their 1500cc V12's against Ferrari, etc. By the late '60s they had almost wiped out Harley Davidson and the entire British motorcycle industry. This was basically ALL due to their very well engineered four strokes.
I apologize if I got my facts wrong on that. I had a source that talked about Honda *not* having a 4-stroke (for their cars) until the Civic engine was completed.
@@AllCarswithJon No problem! Still a neat story I had not heard before!
A bit of irony - the 350 Chevy is easily the most common racing engine in history (cheap horsepower...)
Honda still made a few Ag bikes and dirt bikes in the 60s and 70s as well as two stroke cars as well.
@@ldnwholesale8552 No. Honda never made a two-stroke car and after the early 50s, they did not make another two-stroke motorcycle until the motocross competition-only 250 Elsinore in 1973 and it's street-legal trail bike version in 1975. Are you, by any chance, confusing two cylinder engines with two stroke engines ?
@@CaptHollister yep! Honda motorcycle service tech for 45 yrs. I recall two twin cylinder air cooled 4 stroke cars in the late sixties. Basically just large motorcycle engine adaptations. I brlieve one was the E600 sedan. My boss that owned the Honda motorcyle dealership at that time drove them. Really small...even compared to a later Civic.
Thank you. I was very aware of the CVCC engine when it came out but I had not heard this story. I was a teenager back then and did lot of servicing on Honda 4-Stroke motorcycle engines.
the EPA test results are consistent with a poor adjustment of the main and cvcc carburetor barrels.
I have worked a lot on the CVCC engines and take my word for it, it you lose milage values,
your CVCC aux barrel is not set correctly. I suspect the vortex chamber was too large...
Fascinating. Thank you.
Glad you enjoyed it
Wanker engines don't provide better fuel economy anyway, so looking to them for cleaner emissions was a bad idea.
If it was just fuel economy that created smog, prechamber non-turbo diesels would be excellent.
Interesting. My understanding is the NOx is what caused smog. So not only did it get worse gas mileage, it caused more smog. So they lost on both counts and they lied about it. No surprise.
GM had the catalytic convertor on since 1975 and that was and is the right solution even today. Sounds like GM embarrassed Honda, not the other way around.
I have an '82 civic and live in California. There's a vacuum leak somewhere. I'm trying to sell it. I think that pretty much sums up my experience with cvcc. It was badass back in the day but when no technicians know anything about it and you don't have the time or tools or money to track down all the problems, it becomes impossible
Our 85 Civic Wagon with Cali-spec emissions was great up until it had 250,000 miles on it. Then all of those tiny vacuum hoses and all of those black boxes started to give up due to blistering heat in Texas. It wasn't worth the money to have a specialist fix them all. At least they gave us pretty good trade-in value.
Smoke test the emissions system. You can also just go ahead and replace every single rubber vacuum hose and their plastic connectors. We had similar issues and it's easier to just swap all those parts out and not worry about it.
@@marthamryglod291 Agreed. Get the vacuum line diameter specs, and buy 20+ feet of it. Replace all the vacuum lines one at a time, and it'll be fine. I did this with a California spec 1983 Toyota pickup. Just make sure you don't mess up the routing, by doing them one at a time.
That little red Vega is sweet! That would look great next to my red '88 Cabriolet!
Having higher NOx was probably a side effect of leaner mixture and higher combustion temperatures.
It was a byproduct of leaner mixtures creating higher peak cylinder temperatures. This is why many cars got lower compression in 1971 and EGR in 1973.
The advantage of Contoured Vortex Controlled Combustion is that it's a really cool name. The disadvantage is that it's too expensive to mass produce.
So Honda kept the name and went to a stratified combustion engine.
It was a great engine. I had a little '76 Civic wagon and it was probably the best car I've ever owned.
Very well explained. I believe Japan kept with their designs mostly because of their form of the average typical driver. Being in major cities where there are alot of start and go traffic, there wouldn't be often situations where you would be wide open throttle/high speeds for great lengths in time. Just a guess or plausible based on the generation and what I recall of the infrastructure of that time.
GM is really good at making corporate decisions that don't work. When they bought Lotus they had 2 choices to power the new bodied Corvette. 1. was a motor designed in house by the same guy that designed the quad 4 motor for Oldsmobile, a quad 4 engine modded into a 5+L V8 was proven to put out over 500hp reliably. 2. was the lotus V8 plagued with known problems.
Someone once said the Honda CVCC put out cleaner air than it sucked in ... in smog choked LA.
When I was still a wee lad back in 68 we lived in NorCal, and Dad drove us to Disneyland. As we got closer I saw what I thought were storm clouds over the city and was almost in tears thinking my dream vacation was going to be rained out before Dad explained that it was smog. You really had to see it to believe how bad it was.
I made the mistake of buying a new 95 Monte Carlo. It was horrible build quality and design. Absolute junk.
Anyhow, switched to Ford with decent results. I still own a couple.
But, when I want a great reliable car or truck… I buy Toyota. I’ve had several beginning 2003. Great products.
It doesn’t surprise me a bit, Honda could make a rock run good, great bikes great cars great company.
Axle ratio is the variable that is relevant to all these graphs.If this variable was equalised then then comparison would lean more in the favour of the CVCC tech.The fact that tiny Honda could provide this solution in months while the Big Three were claiming it was IMPOSSIBLE, hints at the lack of integrity in the big business oligarchy of 1970 USA.
I remember back in 1976 driving a Buick station wagon with a 454 V-8 that "couldn't get out of its own way" with a fuel mileage down in the single digits, then driving a Honda CVCC Civic that could move out like a "scared rabbit" with fuel mileage around 45 miles per gallon.
Lol.....a 70's 4 cylinder that could run like a scared rabbit ?
@@HowardJrFord I kid you not! I had a Honda CVCC Civic back in 1976. Front wheel drive and that critter could flat out move! One trick Honda did was to design the engine for high R.P.M. which gave the engine to ability to give high output with small displacement.
A bit of thought. Do you mean 455 not 454???
@@lostinthesauce7175 I think you are correct about the displacement on that old Buick.
And to be fair, Honda embarrassed GM, yes, but specifically Chevrolet. At this time GM was still made up of AUTONOMOUS auto divisions, and Chevrolet had the poorest engineering, poorest engineering budget, or both. There was no saving the Vega, it was a flawed concept with flawed execution. The Chevy experiments with the Wankel rotary and FWD were SO BAD not even Chevrolet would put it into production. Not only was the Vega-based (H body) Monza directly and adversely affected, but also the AMC Pacer (lesson: NEVER depend on Chevrolet for your powertrain). Several times Pontiac had to bail out ***yet another*** Chevy engineering screwup. I suspect Honda may have had a more difficult time embarrassing another division, like Buick.
Some of the mpg hit could be from the cvcc car having a shorter 3.08 rear end, vs 2.97.
My last three vehicles have been a 62 falcon, an 85 town car and a 96 miata. The 85 town car had a 5.0 (302 ci) v8 with cats a smog pump and central fuel injection, falcon had a 170 ci straight 6 with a carb and the miata has a 1.8 (112 ci) twin cam inline 4 with obd 2 and multiport injection. As a backyard mechanic I learned my fair share and the smog and malaise era cars are just like the past two decades of the auto industry to me. There's beauty in the simplicity of the systems that are reliable and work well.
I think you mean your 62 Falcon had a 170 ci straight 6. I don’t think the Ford passenger car 6s grew bigger than 223 until the mid 60s.
@@HoneyTone-TheSearchContinues no you're right, thanks
@@HoneyTone-TheSearchContinues He did say the 62 Falcon had a 170 cube 6.
Great story! It definitely demonstrates how the big US auto companies with their huge engineering groups had some blind spots based on their inability to question themselves. 👍🏻
It's not just the engineers. It's the whole management oversight. The financial decisions. Cost cutting etc. Plus people need to realize that the equipment for manufacturing components such as engine machining lines are not something you just order and it shows up next month. The machining of transfer lines as they are called feature multiple stations that perform one specific operation per cycle. And every cycle the part is automatically transferred from one station to the next. One single set of machinery for machining an engine block can be up to a quarter mile long. From rough end to finish. And that's only doing the block. Add in machinery for the head or heads (1), bearing caps, connecting rods, intake and exhaustmanifolds, pistons, cranks, camshafts etc. And that's just the bare engine. All of this costs money. And once built and installed it is usually intended to be run a long time. I spent 30+ years working in an engine facility so I know something about the subject.
1) Depending on the engine design V type engines can require a seperate machining line for each bank.
Blind spots? The US auto industry of the 1970's was wholly useless, top to bottom.
@@seanm8030
Far too many years of riding with little to no competition. Plus the US auto industry decided to go all in on increased displacement with truely huge V-8s. Yes their were some 6 cylinders offered. The only fours I can think of produced domestically in the early 70s were for Pintos and Vegas. GM might have been building a four for industrial use unless the tooling had been shipped to Brazil.
@@mpetersen6 Yes.
Having worked on this engine for years, pre-chambers were at fuel air ratio of 22:1 and cylinders were at 7:1. Note that staicheomtry is 14:1.
I’ve worked on a CVCC Honda before, absolute nightmare of vacuum lines. Especially as they get older and rubber ages. Honestly one of the most complicated vehicles I’ve had to deal with
I had an 87 Prelude with the 1.8l twin-carb A-Series engine. Also a mess of vacuum hoses with the complexity of the human circulatory system. Save yourself a migrane: Just get a whole roll of vacuum hose and replace ALL the hoses one at a time
It's been nigh-on forever but IIRC there were 32 vacuum hoses under the hood with that engine and you learned to mark them all very carefully on removal. To Honda's credit it did work well when everything was right and allowed them to run carbs two years longer than anyone else could do. God help the mechanic who got one of these where some shade-tree idiot had messed up the vacuum hose configuration 😱
There was one interesting CVCC engine that might not have had so much vacuum junk. The Japan-only Honda Bulldog had the only EFI CVCC engine I know of. There was a turbo version, I don't know how much much vacuum stuff that had.
@@skylinefever Was that also the same engine used in the Japan-only Honda City/City Turbo of the same period? Always thought those were the neatest, coolest mini cars at the time!
@@carlm8821 Yes, I think City II Turbo was the alternative name to the Honda Bulldog.
Beginning in June '72, I started my first job as a young mechanical engineer having just graduated from Univ of Mich concentrating on internal combustion engines and was working for Ethyl Corp in Ferndale, Mich. Among a variety of research efforts, we also did engine dynamometer work for Ford. I was the engineer with eight technicians working for me doing that testing. Some time in late '72 or early '73, Ford purchased the rights to study/develop/produce the CVCC concept from Honda for $50 mil. (That's when $50 mil was real money.) It was big news in the industry. Ford then asked us at Ethyl Corp to setup the CVCC approach on one cylinder of a Ford 460 cubic inch V8 coupled to one of our engine dynamometers as a research tool which we did. It was indeed a research setup; it wasn't pretty, but it did function. We measured emissions levels in the raw exhaust as well as temperatures, fuel used by each of the two carburetors feeding the cylinder, and air consumed by the main chamber and the prechamber as it ran. The three pollutants emitted by cars that were identified in the Clean Air Act of 1970 were hydrocarbons (HC), carbon monoxide (CO), and oxides of nitrogen (NOx). The EPA then came into existence to enforce compliance with the Act. Standards were established for HC, CO, and NOx for the next several years until a reduction of (I believe) 99% was to be achieved by the car makers. As stated in the video, the car makers had little idea how they were going to do it. Running lean and most cars could meet the HC and CO standards albeit with significant performance penalties, but then they couldn't meet the NOx requirements because they couldn't run lean enough to achieve low NOx emissions. Running rich would allow cars to meet the NOx standard but not the HC and CO standards. The CVCC approach was on paper a clever way to run rich in a small prechamber, ignite the rich mixture, then have the flame from the prechamber sweep into the main chamber and ignite the lean mixture above the piston thereby pushing it down and producing power. Overall, with both the prechamber and the main chamber together, it was a lean mixture but was optimized to keep all three pollutants low without the need for a catalyst for help.
By the way, I know of no two-stroke engines in Hondas in the '60s as stated in the video. Did they have them in their own market in Japan? I don't know. All the Honda motorcycles in the U.S. were distinguished by their use of four-stroke engines while Yamaha, Suzuki, and Kawasaki, their main competition, all used two-stroke engines. As background, two-stroke engines use a rich air-fuel ratio to aid in cooling and emit large amounts of HC and CO. They could not be used to meet the exhaust emission standards in cars.
Meanwhile, the application of the CVCC approach on the 460 ci engine was halted a month or two later by Ford after we produced data for them, and we never heard many of the details as to how it was judged by Ford's higher-level engineers. A little over a year later, I left Ethyl and started working for of all places the EPA in Ann Arbor while going to graduate school part time. I worked there a little over four years and worked on motorcycle emission standards (which forced the industry to stop producing two-stroke engines though standards were never promulgated) plus other regulatory papers and such. I watched as exhaust emission standards became more and more stringent. Model year 1974 was a tough year for the internal combustion engine as power and fuel economy was at a low point. Catalytic converters using oxidation catalysts were the norm for cars beginning in 1975 with some power and fuel economy returning. Honda as well as all the rest of the manufacturers eventually came to rely on what is known as three-way catalytic converters where the air-fuel ratio is precisely controlled through use of fuel injection and sensors and HC, CO, and NOx are dramatically lowered making car exhaust consist almost exclusively of CO2 and water vapor. Cars nowadays are clean and capable of extraordinary power and fuel economy. It's a tribute to the industry ... including Honda and General Motors as well as Ford.
As a final note, Honda is technologically very capable, there is no doubt. However, Honda has recently agreed to buy GM's Ultium battery technology products going forward to be installed in Honda vehicles. Honda (and Toyota, too) underestimated how quickly the industry would transition to battery electric for power. So, I wouldn't sell American capability and technology short by any means. There are smart people involved all through the whole car industry.
Fantastic comment and thanks for it!
A couple of things:
First, yes I did seem to get the point about the 2-strokes all wrong; I have it in my script/outline but I think I must have had a 'senior moment' and dramatically misquoted something. Sorry about that.
Second, there's no doubt that Ford and GM have the capabilities, but they haven't always turned that into products quickly or reliably. Personally, I really like what the domestic manufacturers are doing right now and that they're near the front for the move to EV.... so much so that Honda needs a GM platform to hold them over while they develop their own.
@@AllCarswithJon to add to that, Car & Driver magazine recently came out with its 10 Best cars. Three of those cars were GM cars. Mind you, C&D is not a shill for domestic manufacturers. On the contrary, they consistently and inexplicably side with European cars. GM is making outstanding cars. Can you get a turd? Probably, but Toyota has them, too. All things equal, American workers need people to buy American cars. Designers, product engineers, manufacturing engineers … they’re my neighbors, my relatives, my friends. There’s too much bias against domestic brands. Thanks for letting rant a bit. BTW, your video brought back a bunch of memories. I worked with a lot of good people at Ethyl and at the EPA.
1st cvcc civic was 1975 ...the 1200 debuted in 1973. Bestest cvcc ever was 1976/77 accord. I still have the shop mans after 40+ yrs. btw.. when in us army in 70's ..found cvcc design in Russian tech journals..true story frm a 45yr vet of Honda service still fix em everyday!!
The higher fuel consumption is also reflected in the much higher CO2. Something tells me it wasn’t quite sorted as far as fuel mixture goes. That’s a substantial increase in fuel consumption suggesting the fuel mixture was very very rich. I find it hard to believe that it couldn’t have be made to perform as well as the smaller engines with more development, maybe involving a different or modified carburetor. Trying to modify a Rochester Quadrajet must have been challenging. Too bad, but cudos to the savvy engineers at Honda for trying.
My 1973 Impala with the 350 cu in V8 got 11 MPG on a good day.
I had a 71 Cutlass 350 and it got about 15 to 18mpg if I kept my foot out of it. That was the last year before they started butchering them with dropped compression, low cylinder TDC for fun dieseling, airpumps, etc...
I remember an article about this!
Thank you for covering it!!!
The carburetors on the cvcc engines were tremendously complex , and people had a lot of trouble with them .
It was a Kline carb easy pezze 3 bbl carb and the jet valves
ignorance is not a reason to reject a change. Yes they required new learning, and setup procedures had to be followed EXACTLY. Something most American mechanics couldn't adapt to. In Japan they had no issues maintaining the vehicles. Same can be said for Mercedes Benz vehicles, factory maintenance procedures needed to be followed. Or the vehicles ran poorly or had "reliability" issues. Just a different mind set than was typical in USA.
@@chrisyu98 I don't you .....but i have 38 years of experience . that being said i don't think you have clue about repairing a vehicle
Government Motors embarrassed...nooooo🤯
I really enjoy your videos. Just a suggestion, the lighted item on the shelf over your shoulder is really cool looking but quite bright and distracting to your presentation. This is a great story, I've never heard of it ! Thank you !
Good job Honda. gm as a company is very arrogant and glad they are shown for what they really are.
They were. Mary Bara has done wonders with GM but they're still struggling to overcome the crap reputation of the past with almost no money to do that with. The car market is a very tough bullseye to hit these days.
11:13 The two different Impalas had different axle ratios.
I think you meant their over head cam technology was more adept to the cv-cc not their over head valve. Almost all the US automakers were building single cam in block with pushrods to actuate two over head valves per cylinder. By comparison the smaller Honda motors are over head cam and later three and four valve.
Honda running 2 stroke engines? CAP! Soichiro Honda famously hated 2 strokes and only produced a couple motorcycle with them in the 70s.
...fond memories of my neatly put together 1980 Accord, fit and finish much better than "big 3" cars at the time.
1980 Accord?? With the trim all collapsed in the sun. the Honda zeem blowing blue smoke and the general driving experience generally poor. And ofcourse the rust they all have. Three year throw away car. Yes I have owned those things ever only as trades
@@ldnwholesale8552 Dunno. At the time the competition was the joke Plymouth Horizon, etc. It had european econocar roots. I sat in one- a joke. The Honda sedan looked like a tiny Mercedes 300 and was neatly put together. I think I put 100k miles before I traded it. (That was a looooong time ago, btw. The video is about cvcc technology.)
Take a peek:
th-cam.com/video/4EsXqHpjTQU/w-d-xo.html&si=EnSIkaIECMiOmarE
People didn’t care about emissions or engine design they wanted reliability. My friend sold his Maverick in 1975 and bought a Corolla. He took a lot of heat over owning a tiny Japanese car. His response was always “I’ll buy an American car if you’ll fix it.” I always loved big American cars, but in 1988, I sold my 73 Olds Delta 88 and have been driving Toyota, Honda and Subaru cars ever since. When gas was cheap, I bought my cars by the pound, but the price of gas and reliability made buying American cars just plain stupid.
Never heard this story before. Very interesting.
Neither have I.
I had a 1980 Honda Accord with a CVCC engine in it. I abused the living shit out of that thing and it never let me down. The thing was bomb proof. The rest of the car finished it's life as a complete rust bucket and everything from the headlight pots to the door latch mechanisms were trashed, but that engine (and the 5 speed manual tranny) ran better than any other car I've ever owned.
I had an 81 Accord with a CVCC engine. It was a fun car to drive
Me too, i had a metallic green sedan, bought it cheap with 36,000km on it. Fixed a few little things on it and was to sell it, the buyer wanted it delivered to a vehicle transporter on the other side of the city, from the moment i started driving i wished i didnt sell it, it was comfortable, sounded good, not much if any road noise, felt awesome to drive, handled well.. It was just an amazing car. I wish it was my daily driver now. Modern cars dont feel like that at all
I had an '84 Accord CVCC and it did 350,000 miles before we made it into an off roader and took it to the shredder
To add to the last post The 122nd PCT was probably picked Because it was the largest PCT. of all the police Pct's in NYC and the cars assigned there put the most mileage on the cars per year.
As we contemplate new government-imposed EV mandates, I’ve been thinking a lot about this era. The necessity of addressing smog, safety and strategic fuel shortages led to some pretty dismal products (Honda notwithstanding). Beyond the time needed to develop and launch a couple of generations of platforms, it was really only the widespread adoption of fuel injection and computerized engine control that brought drive ability back.
Now the problem is even more urgent. I hope the battery technology is there, but I fear we’ve got another round of poor products we’re going to have to live with.
I tend to agree that any major shift like this has growing pains in the early generation(s). Certainly I can see range, charging networks, electric production and distribution, recycling of batteries, and wholesale upheaval in used car sales coming.
The big difference is this has been brewing for a long time and automakers, states, federal govnmt, and other private parties are all moving forward... together.
There will be bumps, but hopefully not as disruptive as the change from the 60s muscle cars to suddenly power-starved and thristy 8's of the 70s.
@@AllCarswithJon problem is the whole EV push is a disaster. number 1 the national electric grid will NOT be able to handle a huge amount of EV's number 2 the mining of the materials will cause a huge amount of damage to the environment vs current gas/diesel will. and number 3 the avg joe will never be able to afford the crap. you got people who duct tape junkers together to keep running cause they can't afford a $1K repair you think they will be able to afford $27K for battery replacement? no way in hell I could afford to just fork over $27K for a battery replacement I don't have that kind of money and never will.
@@Dratchev241 It's even worse than that. Meanwhile, as I type this, in Wyoming there is yet another trainload of electric car fuel, aka coal, rolling out of the state headed for a power plant. Every time you convert one form of energy into another, you have losses. To operate electric vehicles I see the following:
1. Burning coal to make electricity, which entails converting
a. Chemical energy into heat
b. Heat energy into mechanical energy
c. Mechanical energy into electrical energy
2. Charging the battery, which entails converting electrical energy into chemical energy
3. Driving the vehicle, which entails converting chemical energy into mechanical energy.
There are five energy conversions to move an electric vehicle
In contrast, operating a gasoline vehicle involves
1. Burning gasoline in the engine to convert chemical energy into heat.
2. Converting the heat into mechanical energy.
There are only two energy conversions to move a fossil-fueled vehicle. (I'm also ignoring the refining of gasoline and diesel, which do take energy and have inefficiencies of their own. The power plant can burn coal as it comes out of the mines. I don't know to what degree this offsets the three additional energy conversions with the EV.)
For EVs to serve our needs as efficiently, cheaply, and yes, as cleanly as gasoline and diesel powered vehicles do now, there are going to have to be vast improvements in the way we generate, move and store electricity. And yes, when that battery won't hold a charge anymore, replacement looks like it will cost at least as much as replacing BOTH the engine AND transmission of a gas powered car. How long will a battery last? It's the same technology as cell phone batteries and they last what, 3-5 years? Probably not 26 years like one of my Subarus. The other of my Subarus will turn 24 in March, 2023. I drive these old cars by choice. I can afford a new car, I just don't like most of the cars that have come out since about 2010-too many new technologies at once, too much computerization, too much tracking, too much hackability by those who may not have my best interests at heart. Too much stuff that doesn't have anything to do with getting from point A to point B too integrated with the stuff that does. (I have heard of cases that if the radio breaks, the car won't start because a chip in the radio controls functions of the engine. Then there's always the possibility of a buggy or corrupted software update that breaks things rendering your car useless or even unsafe.) I want an automobile. Just an automobile, not a rolling smartphone.
When and if these issues are worked out, I think EVs will be great, but there is a lot of work that will have to be done to get us there.
@@dr.a.w When you consider the entire life cycle of grid-powered EV's and what it takes to power them during that life, they are currently no better than petro-powered vehicles- possibly even worse for the overall environment and the average owner. I drive older vehicles due to economic necessity mostly, and by choice since I can maintain these myself saving me a ton of money. We've got some tough choices and tough times coming up in the future regards personal transportation and the right decisions will not be the ones people want to live with, so I think people like us are going to exist for quite some time longer.
@@dr.a.w While there is some truth to everything you said, it is amazing how fast people and technology can adapt when forced to. There has been more research in batteries and alternative energy in the last 10 years then in the previous 40 years before that. There are tons of promising developments that people are investing heavily in creating the ability to mass produce them. I see some similarity between the perspective that you typed out, and the perspective of the big three automakers in the 70s, "It cant be done" FULL STOP, and then putting blinders on to the people who are working to solve these issues. Granted, there are no guarantees that any of these technologies will pan out, but it is clear that we can no longer rely on fossil fuels as we use them, and we need to continue to press forward on developing technologies that will allow our children and their children to live on this planet without having to clean up an apocalyptic mess that we left for them.
I had an '86 Civic SI and it didn't use a catalytic. 30+ mpg.
I also had an '85 HF. 50+ mpg.
Interestingly, the gear ratio for the SI in 5th was the same as the HF in 3rd.
I guess this is what happens when companies are controlled by finance guys instead of engineers? Too worried about short term profits instead of long time viability.
One of the things you forgot to look at with the EPA results was the rear differential ratio. 3.08 vs 2.7 means that the stock motor was making 12.3% less engine rpm vs the Honda motor, for the same speed. This also affects the dynamic compression ratio, allowing the fuel to burn more completely because the piston stays at the top of the combustion chamber a bit longer, building more pressure before pushing the piston down the bore.
I will acknowledge what you're pointing out, while saying that's a bit more 'granular' than what I was aiming for in the video. 😀
A CVCC Impala 350 might have been better from a driveability (stall resistant, starts when cold, no hesitation) standpoint than the normal Impala. Also, the cost of manufacturing it had to be less with the CVCC version, since you got to skip cat convertors, EGR, and smog pumps, less parts !! Reliability without all those weird things hanging off the engine would be up too, so, on balance, the CVCC won out. Maintenance headaches down too with CVCC. Add CVCC to microprocessor controls & fuel injection, and then maybe build a 3 or 4 Liter V8 made from 2 Honda 4 cylinder heads (new block and crank obviously), and then you really had a winner.
I'm a mechanical engineer. As you were mentioning the letter to the Academy of Sciences, I heard a previous boss' voice reading the letter as if he wrote it. I have seen issues about money lead to lies like that.
11:46 - The CO2 output was higher. Well, you would expect that. Complete combustion of fuel in an engine results in CO2 and H2O (carbon dioxide and water). If you have more complete combustion, the HC and CO levels are going to go down, and the CO2 is going to go up. 13:46 - "GM was lying to the public" - they weren't lying. They just said they didn't think the technology would work. If that's what they thought, that's what they thought. They didn't research it fully, so they said they thought it wouldn't work. But they're not "lying". Someone isn't lying if they don't actually know something. They would be lying if they tried out the technology, got it to work, and then said it didn't work. But that isn't what they did. It is pretty clear from your last statement, that you "love a good story that embarrasses GM", that you hate GM. Why do you hate GM? Why does anyone hate GM, for that matter? So they didn't do as good a job, and things obviously ultimately didn't work out as well for them. Why would that make you, or anyone, happy? Personally I think what happened to our auto industry is terrible. The competition outdid them. I don't think it's something to be happy about. WE invented cars. Japan didn't. WE were the innovators going back through history. So, our auto industry failing, and all of our manufacturing ability that we once had that went out of this country and is now practically non-existent, is something to be happy about?
You're absolutely correct about the CO2 data. Hoped somebody had mentioned it.
I miss my first car.
1978 Accord.
40 mpg.
But sadly rusted away
I remember the Honda CVCC very well. It was a pre-combustion chamber stratified charge design. It had a small pre chamber that had an extremely rich mix in it and a very lean mix in the main chamber. On paper it worked pretty well but that's on paper. The problem with the pre chamber design is that the combustion event takes way too long. What Honda had to do is they had to retard the timing and limit the advance. Basically the initial timing on their engines ran around top dead center with a total advance of less than 30° at 2,000 RPM. The engine was a 1500 cc engine and believe it or not the 1200 with a standard hemi head combustion chamber could actually outrun it. The very low advanced curve severely hurt power production and fuel economy. After 1980 Honda had to put a catalytic converter on to the vehicle so has to tune the engine with much better fuel mixes in advance curves and yes a 1980 Civic with the same engine could achieve 50 miles per gallon with a 5-speed manual. Previously they could not even achieve 40.
You made a comment about carbon dioxide and carbon monoxide. Carbon monoxide must be limited to as close to zero as possible because it is a deadly dangerous poison. It is a poisonous gas it will kill its victim the reason why is it's one part carbon to one part oxygen. It will rob it's victim of any Oxygen in order to complete itself by having two parts oxygen to one part carbon. That is what carbon dioxide is. It is two parts oxygen to one part carbon. It is the result of complete combustion of any type of fuel. Carbon monoxide is a result of incomplete combustion. Carbon dioxide is not a deadly dangerous gas nor is it a heat trapping gas. You cannot eliminate carbon dioxide because you're breathing carbon dioxide out when you breathe in O2. All living things on this planet except plants breathe in O2 and breathe out CO2. The chemical composition of carbon dioxide is the same whether it comes from respiration or combustion. Complete combustion should only produce carbon dioxide and water vapor. That is considered a pollution free engine.
This really helps me understand how the CVCC engine had lower MPG with so much better combustion gas numbers. I thought it must have to do with ignition timing and heat loss to coolant.
Had a 1980 Honda Accord with a cvcc. Ran beautifully and no catalytic converter. Got 40 mpg highway.