"Where's the Q'jet fans?" Here's one! You have to know that after 40+ years of tuning you learn things. At wide open throttle, the 750 and 800cfm versions of the Q'jet equaled every other carb of the same flow rating. Where the Rochester really shined is at everything below wide open. With interchangeable jets, metering rods, rod hangers, part throttle "power springs" for the primary metering rods, adjustable acc. pump shot, and vacuum and spring adjustable air flappers above the secondary throttle plates the Q jet is tunable over the entire throttle position range of throttle positions between idle and wide open throttle. There's absolutely no question the Holleys are much easier to tune, but the drivability of the Holley can't come close to the Q jet. When accurate fuel mixture anywhere below wide open throttle matters just as much, it's the Rochester hands down. Want better? You have to be willing to learn how to tune for it.
Holley carbs are like Chevy engines. They're everywhere, and they allow kids with no experience to build power easily. Q-jets are a grown man's tinker toy. All the power and smoothness you'll ever need or want, but ya gotta be smart and experienced enough to tune them in correctly.
Q Jet is a great carb. No idea why it gets the disrespect it gets. You have a great carb for cruising with that little 2 barrel then step on the loud peddle and the the toilet bowl opens up and it’s time to fly.
All you guys with your old school black magic. Carbs are dead. You know how hard it is to find a carb tuner now.. they are either dead or in a old folks home.
Q-JET !!!!!!! they work great when you know how to work on them just ask people who run super stock and stock class that have to use them. Ford even used the Q-Jet on the 1970-71 429CJ.
I always preferred a Q-jet for daily driver/street motors, specifically because of the barrel setup. The primaries being a little undersized limit fuel use during cruising, saving gas. Hell, in my '82 Trans Am, I leaned it out a bit and could get 25mpg if I kept my foot off the gas, with an idle RPM of around 600. But those massive secondaries, man - open them up, and just about any V8 with one just ROARS, lol.
I hereby officially award Richard Holdener, PhD status. So he is now Dr Richard Holdener. Congratulations Dr Dick you are champion sir who deserves this highest education qualification as you have been conducting some of the BEST research I have seen here on TH-cam when it comes to experimenting with engine mods to all engines. Take a bow bro you are the BEST!
Awesome video! Love that when something doesn't go quite right you own it and figure it out and fix it. So much knowledge being shared on this channel that otherwise is in danger of being forgotten and lost in the next few years. Great job,sir!
There's no vacuum secondaries on a quarter jet. They're a mechanical secondary with an air valve, a spring-loaded air valve to keep the vacuole up so it pulls air fuel and is air valve opens. It actually takes the shape of a Venturi
I recall reading somewhere that the secondary throttle plates are designed to stop just short of 90* to help direct airflow into the rear cylinders,on certain application. Maybe it was in Cliff Ruggles book?
All I comment on is my personal experience with Q-Jets. In the day, I drove a ton of new cars ( my dads), and my cars (old cars including 455 olds, Buick GS 350 and others.) with Q-Jets. Never EVER once did I experience so much as a hiccup...NEVER! Best things EVER !
My experience with the Quetta is size for size cfm for cfm the q jet makes impressive power with a knowledgeable tuner. The 1971 Pontiac 455 Ho I believe used a 750 cfm Q jet. Most significant problem I experienced was getting a inlet needle and seat large enough to provide enough fuel for the carb to work properly (not run out of fuel). Properly tuned they, the Q jet, works great. enjoyed the test. Thanks for sharing.
I build Qjets and Holleys, both for gas and E85/E100, I like them both a lot. I can coax power out of the Holley easier, but they don't have the drivability of the Qjet. If you know what you're doing, its not hard to get Holley power from a Qjet, it just takes a little more trial and error. The Holley is a lot easier to work on, since you don't need to remove the top like a Qjet. My Qjets do a lot better on gas mileage and still make power on par with the Holleys. Doesn't matter if its a 600 vacuum secondary or an 850 double pumper, I can get that power from a Qjet and still drive it like a daily driver. On E85 its easier to get enough fuel flow and a rich enough AFR with a Holley than a Qjet, the Qjet needs considerably more work, but man do they drive nice on the vodka. 13:1 with iron heads is daily driver stuff on E85, even with a cam that makes a ton of cylinder pressure from idle to 5500.. No need to bleed it off with a bunch of overlap, just throw the vodka at it. Rich is more power on ethanol, if you run it too lean it will still run, just make less power. Stoich isn't where best power happens to be on vodka fuel. Where best power is will depend greatly on the engine, runner length, velocity, chamber shape, cam timing.. all of that makes a big difference on how much fuel an engine wants to make the most power.
Would a "6 tube top" power enrichment system on. Some Q-jets be an advantage running E85. And besides the acceleration pump cup, brass float and the biggest needle an seat ,bigger jets an smaller metering rods is ther anything else you have to do to run E85 using a Q-jet ?
@@dondotterer24 I haven't found any accel pump cups made since 1983 that didn't work. The blue ones for sure work and last a long time. That info came from my testing and passing it on to Cliff. The blue ones are easy to identify, but the only problem I had was with a kit I had sitting around since the late 80s that was made between '79 and '82. I haven't found any others with cup problems. Even when they sit for a year or two on the shelf, they still work fine when I put them back on the car. No problems with gaskets, parts, or anything else. I soaked one in a bucket of E85, open to the atmosphere for an entire year, then I drilled it, put throttle shaft bushings in, and ran it on E85/E100 for 8 years. It was really clean. There is an accel pump circuit restriction in the top cover of some Qjets that needs to be removed, easy enough to do. Sometimes you need to open the orifices as well. Haven't found a problem with brass or foam floats, they all work, but the level is different than gas, its a trial and error thing per model to know where to set it. Ethanol has a different specific gravity so the float sits higher in it. Nobody makes jets large enough for E85, so you just drill some from the bottom, how big varies by model. Drill them, use a check ball to make a new radius in the jet orifice and you're good. The metering rods can be the same ones if you get the jets right, but you want to enrich both front and rear. Start at 25% larger orifices and see where it runs, then sneak up on it by going slightly larger until you get it right. The secondary side is where it gets challenging, .Sometimes you can drill the orifice, sometimes you need to make small rods, its one of those trial and error things where you need a wideband to see where its running. Idle screw passages get opened to .100-.110, I like the windowed inlets and if I get a solid one I drill it twice in an X pattern where the window is on others, and they get drilled to .152, much larger and the needle seat won't seal, but sometimes you can go larger if the needle is big enough. Anything you can do to make it run richer will help, because getting one to 7.5:1 AFR where E85 makes best power is hard to achieve. A small float helps if you can get one, and if it has the plastic plug on the passenger side under the 'hat' you can remove it and add bowl volume... provided it doesn't have the port under the plug drilled. Getting 8.8:1 to 9.5:1 where it gets the best mileage is relatively easy. If you drill the boosters it will pick up a lot of power but it will also use A LOT MORE fuel. My smallest bit is too big, and its like .027 or so. Might work better to 'file' on it with a torch cleaner to sneak up on the target AFR. Every model is slightly different, some need more work in areas than others, it really varies. So it takes me a while to get it all figured out, lots of driving, testing, and watching the wide band. If you have Cliff's book, its a slightly larger version of his 'race' recipe, with a couple extra changes like the accel passage. If you don't know how Qjets function, you can really screw one up.
@@SweatyFatGuy Yep. My last one I bought from you. And have told many people to buy everything they need from you. And explained why. And I will do the same. BTW what do you think of what they done during the test? Do you think they should of changed the secondary throttle blade angle when they put it on the aluminum intake?
Thanks for the time and alot of information! I do have Cliffs book. My friend Ken Shawver that used to run super stock has run one even without the primary metering rods.
Hey Rich,Thanks for excellent video .I would rebuild the Q.jet carb during my coffee break and run only part throttle primaries during work week and wide open on weekend.Got the best of both worlds with Q.jet.
Nobody's mentioned yet that a .060 over Cad 500 is 514. Just saying. But it's freaky listening to a dyno pull starting at 2000 and ending at 5500. The engine never sounds stressed.
It's amazing the horsepower gains that the basically stock, original carburetor can support. I can't think of any other stock carbureted engine (besides other q-jet engines) where you can double the horsepower on the original carb.
Love it. What a great content. Your 3-4% power increase rule per point of CR seems to apply in this case as well. Increased CR by 3 points increased power around 10%.
Had 64 Chevy back in 1995 that I had bought a 500 Caddy to swap in. Had a kiddo and that went down the road! I'm older and a little wiser these days. Mayyybeee!
Really enjoy these 'in depth' comparisons! That 500 Caddy is a driveshaft twisting beast! Boost? Slap an 8-71 blower on that bad boy and let's see what it does!
Richard, can you show and give more details on the head modifications, flow numbers, etc? Built a very similar 500 for a military M715 4x4 20+ years ago. Mine had forged JE "D shape dished" pistons for 10 to 1 compression. I used Oldsmobile 425 forged rods (bolt in with custom pistons). I had a massive amount of time in the early 76cc heads. Machined for 2.19 and 1.77 Pontiac valves, un-shrouded chambers, ported through the push rod reliefs and patched with epoxy. A 238 @ .050 custom ground cam. Started with a custom welded Ford 460 intake W/ spacers, then a fabricated sheet metal cross ram intake, but switched to the Edelbrock when it came out. Never put it on the dyno, but I estimated around 525 HP and 550 torque. It was happy to rev to 6000 RPM although it was done pulling hard by 5500. It was an overpowered scary beast off roading in that old truck that needed suspension upgrades to match the power. The truck: drive.google.com/file/d/1Dx9uIzrUbfzyeLZUkOE0zS5VVnKBFRCU/view?usp=sharing
holley is a great replacement carb,fairly inexspensive and a little more flow and tuneabilty.[easier to tune].anybody who got to tune a q-jet or weber or ect for there cars emission or performance back in the 70's thru 90's had to learn how to bend rods and drill out carb bodies,not needed on hollies.test will be close but give it to holly.took a little tweaking but got a 71-buick 455 riv to pass 80's emission's.keep up the good work.
I love what he is doing here. I build a few engines and I have a friend that owns a Superflow 901 dyno with the later windyn software. I have also done some things like this where we would try different things on the engine trying to get an improvement in the power numbers. Even things like changing the air bleeds on the Holley carbs will make a big difference on certain combinations. It's always fun and educational to be able to do this and I especially enjoy what Richard is doing here and respect that it's a lot of work to do all the parts swapping, taking the thing apart time after time, many times to be disappointed at the results. I must tell everyone that this is the real way to use a dyno, it's a tool for learning and that Richard's work can help everyone see how things need to be done so a to get proper results. Great job on this and every other engine project he has done.
this is a damn good comparison video with a motor that i always found fascinating....big brute torque at an ultra low rpm and massive power from the caddy!
I love the QJet. I guess because it took me to school.lol. I had to learn so much just to understand the basic function. After a buying a used junker QJet. Cliff Ruggles book and hours at the kitchen table,don't tell my wife. I ordered Cliffs rebuild kit. Dial in the APT and larger down tubes. The Qjet is a wonderful carb now. My 780 Holley VS with 79/84 runs well but doesn't have the throttle response like the QJet. But the Holly seems to fell stronger from 4k to 5200rpm. But that just might be me idn
Agreed. Quadrajet has those nice snappy "small" primaries. Makes them great on the street when just cruising around at part throttle and then mashing your foot to the floor. It's really my favorite out of the Factory OEM carbs by far. Sure it's more difficult to take apart, service, etc. but that's because it designed really to just be left alone and ran on a factory stock engine. But they are capable of greatness. Especially in offroad applications.
@@thefinalroman While in theory you may have had an argument given the small cross section singling out SMOG era cars of the mid-70's to late 80's combined with the built in obsolescence factor from the same era designed to promote continual refresh the quadrajet was around long before that time as a very reliable carb used on a large percentage of the most powerful and respected cars that US auto manufacturers ever made which are still highly sought after to this day. In regards to "nobody buys american cars anymore" well.. Worldwide automotive sales figures would tend to disagree with that with combined totals of between 15 million and 17 million units annually over the past 7 years.
@@thefinalroman quadrabog,-dog,-junk,-smog blah blah blah blah!!! Ive heard it all. Don't bash it due to lack of patience and understanding on your part. That's simply elementary my dear Watson. Elementary.
@@pjmccoy4216 Lol those carbs were trash. Forf,Chrysler,Honda,Toyota had good carbs but those quadrabog junks never started ran like crap leaked gas stalled out and even when they worked the 305 dog motor with a quadrajunk barely got 10mpg. People want a car that runs not a piece of shit you can polish all day and never get out of the garage....
Love it! The caddy is pretty strong. I actually expected it to be more torque biased than the Buick but then again these are ported heads versus non so that makes a difference.
That's a big maybe. You might have to cut some timing but the gain is power the 99% of the time you're not at wot will be worth it. It will also idle way better. If it was put together for this and had things like positive deck pistons, 035 or less quench clearance and polished chambers and piston tops it would probably run no problem with a 160° thermostat. At the drags or even doing pulls on the street it would be fine. If you put it in a one ton pickup and tried to pull a trailer up a grade for miles, you'll run into issues pretty fast. Hot rod built an 11 to one all iron small block fifteen years ago that didn't pick up any power with fuel above 87 octane. It can be done.
I used to be pretty good with Q-Jet's. The first thing I did was to have my buddy TIG weld the leaky plugs in the bottom of the float bowl, then start massaging the jets and metering rods and adjusting the secondary air valves. Way more reliable than the Holly's with the old power valves that almost always needed replacing after a backfire.
Maximum Torque Specialties in MA had a kit to drop a 1970 500 into a Malibu of that era. They ran 11's without modifying the 400 hp engine. Before the 502 Chevy was cheap enough to buy used at swap meets, a Cad was the secret for Chevy/GMC pickup trucks. Buy one at the junkyard, get the 425 single plane intake, Chevy or Ford 429 header tubes welded onto an aftermarket flange, and don't worry about the low compression--you had a beast for towing, with diesel like torque off idle. Nowadays, of course, you can pick up a motorhome 454, it won't be sludged with motoroil like a 1970's engine, and make decent power that shocks the LS fanbois who think anything older than them must suck.
I've used Qjets several times. That sound as the secondary's start gulping is priceless. And the dependability beats holley's hands down. I only did Holley carbs for extreme uses. That's where they shined.
I’ve worked on most all carburetors and modified ones , I’ll take the Quadrajet every time.! Less parts and it can be taken apart while it’s still mounted on the engine… never been a Holly fan to many issues with them ( but they do have a broader cfm flow ) plus when on a 4x4 in various terrain they cut out unless you buy the float springs which will fail after a period of time.. Q-Jet all the way.!!!!
Richard...i just love the Other Guys ...500inch Caddys ..Big 460 Fords...Cant wait to see what kiind of power the Caddy will make with the single plane intake and the Holley Carb...this is Hot Rodding at its Finest ..👍❤🇺🇸
Man Richard this is some fantastic stuff your putting out. Much respect to Cad company guys for going against the grain and building real performance parts for lovers of the Cadillac motor.
They came with a TH400 from the factory, just with an extremely long (somewhere in the 14" range) tailshaft. Nice part is BOP TH400s are alot easier to come by for cheap than chevy versions.
Not a competitor.. a 454 has 92% of the CID of a 500 cad and zillions more head choices at the junkyard. 454 + junkyard heads + cam over 500 cad every day of the week.. much cheaper n better.
Nothing like the howl of a Q Jet secondaries, I have enjoyed that sound since being a teenager in the 70's. I put a 500 Caddy from a 70 Eldo in my lifted 35" tired Suburban, the hardest part was rebuilding a Caddy transmission with a short output shaft for the transfer case. Engine was box stock and ran MUCH better than the 350 I pulled out, with 4.56 gears it was a beast off road.
Hi, Need 'O2 ' sensors in each exhaust port . on the ' Q-JET , Let the secondary butterflies open past 90* decrees to put more fuel to the front Cylinders . Check fuel pressure @ the fuel inlet on the Q-JET To Prevent A lean condition .
As an avid enthusiast I find it puzzling that most magazine and video tests will give results of their findings with great detail but in my mind forget a very important one,, Fuel Octane used to get the results without detonation and how much total timing was used to get there on each engine. Basics in my mind. I would also like to see how much power I can get with pump piss fuel like you have in CA on a milder engine or the Cadillac 500 here but there is no info. Not all street guys have the luxury of race gas to mix in. Love your channel and very interesting content. Subscribed.
@@richardholdener1727 Thanks for the reply. I think it would be very informative to list what fuel you use on any test of anything. If you did you will be one of the very few. What fuel did you run on the high compression 500 caddie engine then?
Have any Q-Jet guys tried using a Model #17085213 from a 1985-88 or so one ton Chevy pickup? This is a non-electronic carb with more adjustments than almost any other Q-jet. Without pulling the air horn you can adjust both upper limit and lower limit travel on the primary metering rods. There is also an adjustable air bleed in the secondary circuit, under a brass plug on the back of the carb. There is also the usual spring tension adjustment on the secondary air valve as well as secondary metering rod and hanger adjustments. So this carb can be fine tuned much quicker and easier than a Holley!
Dam you Richard. You are telling the world how great these 500 cubic inch Cadillacs are. The prices on them are going to skyrocket and the boneyards will be picked dry.
I run a 800 cfm Quadrajet off a 73 or 74 DeVille Cadillac 500 on my 30 over 11 to 1 compression 1967 425 olds . I rebuilt the Quadrajet I didn't even have to mess with the primary or secondary metering rods. The only thing I had to do is adjust the idle mixture screws runs like a top I'll take a Quadrajet over a Holley any day. ;)
Olds stuff (even more than Pontiac) is rarely found, at least valuable/accurate content. Bill Travato did a bada$$ turbo Olds from a 350 diesel block. If anyone could pull it off its Richard. It'd make a Great addition in "the other guys" series though
@@richardholdener1727 I doubt that anyone cares but I put a 403 olds in my 69 cutlass and compared it to the 350 olds that came out of it on my channel
Hard to see but I think the secondary air valve wasn't opening enough. I'm guessing they will loosen up the tension on it to provide more air and fuel lifting the metering rods out of the orifices and maybe a metering rod change or a metering rod hanger change also. Maybe some other mods requiring the top to come off. Might have to change the secondary throttle blade angle also
I probably missed the question when you started the 500 CI tests but I would like to know the weight of this motor with all the stock cast iron head's and intake?? Did you even consider weighing the motor?? Thanks Richard.
Big fan of the Q jet. The problem with the q-jet is the aftermarket doesn't care for it. They think it's difficult and hard to work on. So intake manifold companies don't bother to make much over a 5500 RPM manifold for them
I used to run the q-jets on my old Chevy trucks for the sound alone. The performance gains from other carbs couldn't win me over. I thought the q-jet performance was really good anyhow. I always had success with the q-jet
Well I'll tell you a story. Had a 79 firebird 400 BB, mild cam, elderbrock intake, long tube headers. Had a jetted 800 quadrojet on it my dad tuned. It rocked with the quadrojet. Put a 780 double pump on it and my dad told me it would slow down with Holley. Sure as crap I lost 60 hp or more with the holley. Took it off put back on quadrojet.
Q-Jets are good carbs till they fall apart inside, or the throttle shafts wear out. My heartburn with them was more associated with the stock, low riser, iron intake manifold that it sat on. I remember a few non--car enthusiasts back in the 70s that swapped their defective Q-Jets in their Impalas, etc. with the new Holley spreadbore replacement carb that came out. And they were happy.
nothing wrong wilt a Q-jet if you how to work on them, never seen a Holley spread bore or Holley used on a street engine that would would run as well on a automatic car unless it had a high stall converter, the air valve and vacuum dash pod adjusted right will let you leave without bogging like holley's especially on small ci engines and heavy cars.
I have always loved a quadrajet. Get plenty of cfm for power and kick out excellent fuel mileage as long as you dont get in the secondaries. Ended up running a 780 cfm quadrajet on a 72 318 Chrysler I rebuilt. Way better than the thermoquads or Holley's for a daily driver in my opinion.
You should contact Justin minahan he runs a Nostalgia dragster in the west coast Nostalgia drag Association known as ANRA. Copper Cadillac, its a bad ass ride
Something about a Holley carb on a Caddie goes to gather like peanut butter and sauerkraut. This engine is a BLVD beast. Sounds funny on the Dyno. Were most engine are just coming to life, this thing is done with some very impressive numbers.
Great Show !! Are the pistons stock , overbored ? Forged ? Stock pistons pretty strong ! 70 Eldo Cam @ 400 h.p. stock !!! Use Big Ford dual quad intake w/ Adapters That Eng. WANTS MORE Throttle Plate Area Pair OF 660,s or bigger if it will stay clean. IF Good Parts ARE in it Raise that RPM. Limit ! That Combo Ought to Do Over 600 HP. Thanks .
Great video! What exactly is the weak link, or links, on these engines, rods, oiling system, crank? Sounds like it’s just starting to get happy at 5000 lol.
Is something wrong with the current lot of hydraulic lifters, seems a lot more issues with them than in the past. Has the quality been reduced. The only issues you use to see was ‘pump up’ and loss of valve control over 5000rpm?
Michael Angelo I guessed that, but who is going to start paying for rebuilding engines destroyed by hydraulic lifters that have lost their guts. We need to name and shame companies that sell sub standard parts, more so us backyard engine builders with low budgets don’t loose out.
@@michaelangelo8001 I don't think that's quite true. They do two different things. I think.of Richard as the lab tech, and Tony as the field guy. Don't forget, Tony has a history in this world that goes back almost 40 years. He.must be doing something right.
@@ericlandstrom6155 I'm not putting anyone down, but I have more "history" than either of them. When I saw Richard's first video attempts, I was disgusted, frankly. He looked an acted like an arrogant, know-nothing, baldheaded jerkoff. But now that he's dropped the fake act, and started putting real meat and potatoes on the table, I can see that the guy actually has an incredible amount of experience in comparison to your average internet wannabees. Tony knows the ordinary things that all of us with any experience with cars already know, but Richard takes us into a world that 99% of us could never afford to experience. Dyno time is VERY expensive, and most people in this audience can not afford it. Everytime you watch one of these videos, it's like he is just handing you money. Tony bores me, I know lots of people like him, personally. But the information that Richard provides is on a completely different level.
This is motor I want to put in a 32 ford . Tired of seeing the small blocks . A 450 hp 550 torque cad motor in a 32 would do the job nice . I would guess 11 second quarter mile times?
its a wide engine to toss in that engine bay (in the day, folks preferred the Buick nailhead on Model A's due to the narrow width) and there's the length of the front water/oil pump and filter, but you'll certainly want highway gears, maybe even a Buick two speed to kill launch torque. Otherwise you'll do 11 seconds b/c you're blowing the tires away at launch. Of course, a Ford in a Ford isn't a bad deal, either. A low deck Windsor is nice and light, or a crate 427 cid tall deck Windsor would have all that torque you want and run EFI cheaply, too.
@@tedteddy2293 that's what made them such a great engine in a brick nosed Chevy pickup you used to pick up cheap. All that room in the engine compartment for 'em with diesel-like torque. And Chevy BB headers for those slabside trucks could be cut to fit the Caddy.
richard, can you do graphs that show the comparison to the previous run. so we can see changes in the shape of the curve as well as the outright difference.
All these swaps are with flat teppet? New lifters and break in each time? Love the BPO and Caddy tests. It was my world for a time. A few 350 Rocket cars. Rev them high!
On the dyno it's really hard to quantify it. Youre only looking at power at wide open throttle. If you take a new Ls2 crate engine and put the biggest cam you can fit to the valves and take another an put the highest flowing largest port heads on it, they will have similar power curves. When you start to compare these at part throttle you will get some substantial differences. If the factory or ported heads had huge port volumes, it would really cripple the low end torque with the bigger camshaft especially at part throttle.
@@richardholdener1727 that depends. An ls2 will gain somewhere north of 90hp with a max effort cam swap, and a stock cammed ls2 will gain about 45 with max effort heads. If you do the same comparison on an ls3 it's not even close, the factory heads are too good and max effort porting doesn't do too much. What if you had an L78, it's got pretty aggressive cam timing and pretty good heads but the huge dome on the piston might cut your fun early, and the factory heads don't flow over 300cfm until 700 lift, where a modern set of cnc ported heads might make lots of power with the factory camshaft. That's why I specified ls2. I don't know what the cam is like in this Cad stock but probably less than 190@050 and around 400 lift. It doesnt matter what head you put on it at that point, not a lot will happen. My point is with an ls2 the shape of the curve will be similar. My point also stands that putting a cam with 600 lift and 240@050 might work really good at even 2500rpm on the dyno with no manifold vacuum, that camshaft is going to cause issues at 1500rpm and 15" of vacuum. I can't find the port volumes of these heads but they look like they are in the 240-260cc range. Really small for the 514 cubes they are tasked with feeding. Do you think you could overcam a 500 inch ls stroker with stock ls1 heads, or do you think that every camshaft up to the big cam here you put in will add power everywhere when you test it on the dyno?
Richard, Since you are running other guys motors. Maybe when you get to boosting the 500 you could do an exhaust comparison? Stock cast manifolds, vs. logs, vs. short turbo headers, vs. long tubes?
Note that the power is at very low RPMs in comparison to an LS, etcetera. What kind of valve gear are they running on this engine... modified Buick, early Ford?
You could do a really nice cnc chamber on those small chamber heads and drop comp to around 10-10.5:1 and run it on pump fuel. Might get close on power.
"Where's the Q'jet fans?"
Here's one!
You have to know that after 40+ years of tuning you learn things.
At wide open throttle, the 750 and 800cfm versions of the Q'jet equaled every other carb of the same flow rating.
Where the Rochester really shined is at everything below wide open. With interchangeable jets, metering rods, rod hangers, part throttle "power springs" for the primary metering rods, adjustable acc. pump shot, and vacuum and spring adjustable air flappers above the secondary throttle plates the Q jet is tunable over the entire throttle position range of throttle positions between idle and wide open throttle.
There's absolutely no question the Holleys are much easier to tune, but the drivability of the Holley can't come close to the Q jet.
When accurate fuel mixture anywhere below wide open throttle matters just as much, it's the Rochester hands down.
Want better? You have to be willing to learn how to tune for it.
Holley carbs are like Chevy engines. They're everywhere, and they allow kids with no experience to build power easily. Q-jets are a grown man's tinker toy. All the power and smoothness you'll ever need or want, but ya gotta be smart and experienced enough to tune them in correctly.
Q Jet is a great carb. No idea why it gets the disrespect it gets. You have a great carb for cruising with that little 2 barrel then step on the loud peddle and the the toilet bowl opens up and it’s time to fly.
Best carburetor ever build
All you guys with your old school black magic. Carbs are dead. You know how hard it is to find a carb tuner now.. they are either dead or in a old folks home.
I am 34 and could tune a carb blindfolded. Carbs aren't dead, plenty of race cars and street rods atill run them.
Q-JET !!!!!!! they work great when you know how to work on them just ask people who run super stock and stock class that have to use them. Ford even used the Q-Jet on the 1970-71 429CJ.
7.73 on a quadrajet
I always preferred a Q-jet for daily driver/street motors, specifically because of the barrel setup. The primaries being a little undersized limit fuel use during cruising, saving gas. Hell, in my '82 Trans Am, I leaned it out a bit and could get 25mpg if I kept my foot off the gas, with an idle RPM of around 600.
But those massive secondaries, man - open them up, and just about any V8 with one just ROARS, lol.
Yes, and they won't burn your car down like a Holley.
Holleys are famous for running over and starting a gas fire.
They do have a sound
I always ran Holleys on my hot rods back in the day. Now that I know better, I wish I still had some of those cars.
I hereby officially award Richard Holdener, PhD status. So he is now Dr Richard Holdener. Congratulations Dr Dick you are champion sir who deserves this highest education qualification as you have been conducting some of the BEST research I have seen here on TH-cam when it comes to experimenting with engine mods to all engines. Take a bow bro you are the BEST!
Awesome video! Love that when something doesn't go quite right you own it and figure it out and fix it. So much knowledge being shared on this channel that otherwise is in danger of being forgotten and lost in the next few years. Great job,sir!
Thank you for adding this insight.
I agree the reality of the process is not lost here .rich is the most detailed and easy to understand
I'll watch anything he does. Ty rich!
The sound of vacuum secondaries opening up under power on a qjet will never be forgotten ❤️ unfortunately I only remember Holley for engine fires
Cuz they leak like a Harley!
I once counted 17 places they could leak and probably missed a few.
There's no vacuum secondaries on a quarter jet. They're a mechanical secondary with an air valve, a spring-loaded air valve to keep the vacuole up so it pulls air fuel and is air valve opens. It actually takes the shape of a Venturi
Id like to see 8 o2 sensors with a q jet vs Holley to see if the q jet has distribution issues with big and little butterfly's.
You know that's a damn good idea I second that
That would be awesome! That and also swap out different intakes
I recall reading somewhere that the secondary throttle plates are designed to stop just short of 90* to help direct airflow into the rear cylinders,on certain application. Maybe it was in Cliff Ruggles book?
that would be cool
@ my qjet would suck the bowl dry on a 402ci chevy
All I comment on is my personal experience with Q-Jets.
In the day, I drove a ton of new cars ( my dads), and my cars (old cars including 455 olds, Buick GS 350 and others.) with Q-Jets.
Never EVER once did I experience so much as a hiccup...NEVER!
Best things EVER !
My experience with the Quetta is size for size cfm for cfm the q jet makes impressive power with a knowledgeable tuner. The 1971 Pontiac 455 Ho I believe used a 750 cfm Q jet. Most significant problem I experienced was getting a inlet needle and seat large enough to provide enough fuel for the carb to work properly (not run out of fuel). Properly tuned they, the Q jet, works great. enjoyed the test. Thanks for sharing.
I build Qjets and Holleys, both for gas and E85/E100, I like them both a lot. I can coax power out of the Holley easier, but they don't have the drivability of the Qjet. If you know what you're doing, its not hard to get Holley power from a Qjet, it just takes a little more trial and error. The Holley is a lot easier to work on, since you don't need to remove the top like a Qjet. My Qjets do a lot better on gas mileage and still make power on par with the Holleys. Doesn't matter if its a 600 vacuum secondary or an 850 double pumper, I can get that power from a Qjet and still drive it like a daily driver.
On E85 its easier to get enough fuel flow and a rich enough AFR with a Holley than a Qjet, the Qjet needs considerably more work, but man do they drive nice on the vodka. 13:1 with iron heads is daily driver stuff on E85, even with a cam that makes a ton of cylinder pressure from idle to 5500.. No need to bleed it off with a bunch of overlap, just throw the vodka at it. Rich is more power on ethanol, if you run it too lean it will still run, just make less power. Stoich isn't where best power happens to be on vodka fuel. Where best power is will depend greatly on the engine, runner length, velocity, chamber shape, cam timing.. all of that makes a big difference on how much fuel an engine wants to make the most power.
Would a "6 tube top" power enrichment system on. Some Q-jets be an advantage running E85. And besides the acceleration pump cup, brass float and the biggest needle an seat ,bigger jets an smaller metering rods is ther anything else you have to do to run E85 using a Q-jet ?
@@dondotterer24 I haven't found any accel pump cups made since 1983 that didn't work. The blue ones for sure work and last a long time. That info came from my testing and passing it on to Cliff.
The blue ones are easy to identify, but the only problem I had was with a kit I had sitting around since the late 80s that was made between '79 and '82. I haven't found any others with cup problems. Even when they sit for a year or two on the shelf, they still work fine when I put them back on the car.
No problems with gaskets, parts, or anything else. I soaked one in a bucket of E85, open to the atmosphere for an entire year, then I drilled it, put throttle shaft bushings in, and ran it on E85/E100 for 8 years. It was really clean.
There is an accel pump circuit restriction in the top cover of some Qjets that needs to be removed, easy enough to do. Sometimes you need to open the orifices as well.
Haven't found a problem with brass or foam floats, they all work, but the level is different than gas, its a trial and error thing per model to know where to set it. Ethanol has a different specific gravity so the float sits higher in it.
Nobody makes jets large enough for E85, so you just drill some from the bottom, how big varies by model. Drill them, use a check ball to make a new radius in the jet orifice and you're good. The metering rods can be the same ones if you get the jets right, but you want to enrich both front and rear. Start at 25% larger orifices and see where it runs, then sneak up on it by going slightly larger until you get it right.
The secondary side is where it gets challenging, .Sometimes you can drill the orifice, sometimes you need to make small rods, its one of those trial and error things where you need a wideband to see where its running.
Idle screw passages get opened to .100-.110, I like the windowed inlets and if I get a solid one I drill it twice in an X pattern where the window is on others, and they get drilled to .152, much larger and the needle seat won't seal, but sometimes you can go larger if the needle is big enough.
Anything you can do to make it run richer will help, because getting one to 7.5:1 AFR where E85 makes best power is hard to achieve. A small float helps if you can get one, and if it has the plastic plug on the passenger side under the 'hat' you can remove it and add bowl volume... provided it doesn't have the port under the plug drilled.
Getting 8.8:1 to 9.5:1 where it gets the best mileage is relatively easy.
If you drill the boosters it will pick up a lot of power but it will also use A LOT MORE fuel. My smallest bit is too big, and its like .027 or so. Might work better to 'file' on it with a torch cleaner to sneak up on the target AFR.
Every model is slightly different, some need more work in areas than others, it really varies. So it takes me a while to get it all figured out, lots of driving, testing, and watching the wide band.
If you have Cliff's book, its a slightly larger version of his 'race' recipe, with a couple extra changes like the accel passage. If you don't know how Qjets function, you can really screw one up.
@@SweatyFatGuy Yep. My last one I bought from you. And have told many people to buy everything they need from you. And explained why. And I will do the same. BTW what do you think of what they done during the test? Do you think they should of changed the secondary throttle blade angle when they put it on the aluminum intake?
@@SweatyFatGuy sorry I thought you were cliff I didn't read. But if you will pass it on to Cliff please.
Thanks for the time and alot of information! I do have Cliffs book. My friend Ken Shawver that used to run super stock has run one even without the primary metering rods.
Hey Rich,Thanks for excellent video .I would rebuild the Q.jet carb during my coffee break and run only part throttle primaries during work week and wide open on weekend.Got the best of both worlds with Q.jet.
Gotta say nothing else sounds like a WOT Q-jet on a high compression big block. Whaaaaaa...I'm coming for U
Great series also. These engines were big for too short of time. I still run the Larry Krusick cam from 30 years ago.Great guy.
Very cool!!
Love hearing the engine's run on the dyno!
Thanks Richard!
500 foot pounds of Torque @ 2000 with a 248 degree cam.
I don't think I've ever seen that much down that low with a cam that big. Really amazing.
Love waking up to Coffee and Richard lol.
Sippin on some high octane liquid right now!☕☕
I'm hittin the milk....straight up
“Coffee and Richard” sounds a bit more suspect
@@HioSSilver1999 🤣
Special Agent Jim Harris, SSD. Lol
Nobody's mentioned yet that a .060 over Cad 500 is 514. Just saying.
But it's freaky listening to a dyno pull starting at 2000 and ending at 5500. The engine never sounds stressed.
It's amazing the horsepower gains that the basically stock, original carburetor can support. I can't think of any other stock carbureted engine (besides other q-jet engines) where you can double the horsepower on the original carb.
Thermoquad comes to mind for one example. Some thermoquads were 1000cfm.
@@wildrosegarage4208 Thermoquads were originally designed as "performance" Qjet replacements.
Quadrajet guy right here.
Love the Cad 500 motor! Years .....many, ago, I put a 500 into a 1968 Riviera. All stock and not fast. But would do burnouts from Hell!!!!!
Did you use a 425 belly button pan?
Love it. What a great content.
Your 3-4% power increase rule per point of CR seems to apply in this case as well. Increased CR by 3 points increased power around 10%.
Q-jet needs me to tune it, LOL. Power piston spring, primary jets and rods plus secondary rods and hanger. All need changing.
Cadillac = cubic inches! That’s fun! Great “other guys” story, Richard, looking forward to seeing more.
Ya know... I've never seen one really revved up. Like to 7-8 grand lol
Had 64 Chevy back in 1995 that I had bought a 500 Caddy to swap in. Had a kiddo and that went down the road! I'm older and a little wiser these days. Mayyybeee!
Really enjoy these 'in depth' comparisons! That 500 Caddy is a driveshaft twisting beast! Boost? Slap an 8-71 blower on that bad boy and let's see what it does!
that's exactly what I was thinking!
Those numbers are incredible!!! The torque curve is a perfect for some street fun
Agreed!
This era of cadillac really were engineered so well these engines are dead reliable and super balanced with unmatched smoothness .
Cant wait to see boost!
I'm thinking the perfect truck/4×4 engine.
Hell of a street motor
Richard, can you show and give more details on the head modifications, flow numbers, etc?
Built a very similar 500 for a military M715 4x4 20+ years ago. Mine had forged JE "D shape dished" pistons for 10 to 1 compression. I used Oldsmobile 425 forged rods (bolt in with custom pistons). I had a massive amount of time in the early 76cc heads. Machined for 2.19 and 1.77 Pontiac valves, un-shrouded chambers, ported through the push rod reliefs and patched with epoxy. A 238 @ .050 custom ground cam. Started with a custom welded Ford 460 intake W/ spacers, then a fabricated sheet metal cross ram intake, but switched to the Edelbrock when it came out.
Never put it on the dyno, but I estimated around 525 HP and 550 torque. It was happy to rev to 6000 RPM although it was done pulling hard by 5500. It was an overpowered scary beast off roading in that old truck that needed suspension upgrades to match the power.
The truck: drive.google.com/file/d/1Dx9uIzrUbfzyeLZUkOE0zS5VVnKBFRCU/view?usp=sharing
I don't have flow numbers unfortunately
Awesome truck
holley is a great replacement carb,fairly inexspensive and a little more flow and tuneabilty.[easier to tune].anybody who got to tune a q-jet or weber or ect for there cars emission or performance back in the 70's thru 90's had to learn how to bend rods and drill out carb bodies,not needed on hollies.test will be close but give it to holly.took a little tweaking but got a 71-buick 455 riv to pass 80's emission's.keep up the good work.
Favorite part of this site. Absolutely love the Other Guys content!
I love what he is doing here. I build a few engines and I have a friend that owns a Superflow 901 dyno with the later windyn software. I have also done some things like this where we would try different things on the engine trying to get an improvement in the power numbers. Even things like changing the air bleeds on the Holley carbs will make a big difference on certain combinations. It's always fun and educational to be able to do this and I especially enjoy what Richard is doing here and respect that it's a lot of work to do all the parts swapping, taking the thing apart time after time, many times to be disappointed at the results. I must tell everyone that this is the real way to use a dyno, it's a tool for learning and that Richard's work can help everyone see how things need to be done so a to get proper results. Great job on this and every other engine project he has done.
this is a damn good comparison video with a motor that i always found fascinating....big brute torque at an ultra low rpm and massive power from the caddy!
I LOVE THE ROCHESTER QUADRAJET CARBURETOR.
I love the QJet. I guess because it took me to school.lol. I had to learn so much just to understand the basic function. After a buying a used junker QJet. Cliff Ruggles book and hours at the kitchen table,don't tell my wife. I ordered Cliffs rebuild kit. Dial in the APT and larger down tubes. The Qjet is a wonderful carb now. My 780 Holley VS with 79/84 runs well but doesn't have the throttle response like the QJet. But the Holly seems to fell stronger from 4k to 5200rpm. But that just might be me idn
Agreed. Quadrajet has those nice snappy "small" primaries. Makes them great on the street when just cruising around at part throttle and then mashing your foot to the floor. It's really my favorite out of the Factory OEM carbs by far. Sure it's more difficult to take apart, service, etc. but that's because it designed really to just be left alone and ran on a factory stock engine. But they are capable of greatness. Especially in offroad applications.
Q jets are trash. The quadrabog was the reason no one buys american cars anymore....
@@thefinalroman While in theory you may have had an argument given the small cross section singling out SMOG era cars of the mid-70's to late 80's combined with the built in obsolescence factor from the same era designed to promote continual refresh the quadrajet was around long before that time as a very reliable carb used on a large percentage of the most powerful and respected cars that US auto manufacturers ever made which are still highly sought after to this day. In regards to "nobody buys american cars anymore" well.. Worldwide automotive sales figures would tend to disagree with that with combined totals of between 15 million and 17 million units annually over the past 7 years.
@@thefinalroman quadrabog,-dog,-junk,-smog blah blah blah blah!!! Ive heard it all. Don't bash it due to lack of patience and understanding on your part. That's simply elementary my dear Watson. Elementary.
@@pjmccoy4216 Lol those carbs were trash. Forf,Chrysler,Honda,Toyota had good carbs but those quadrabog junks never started ran like crap leaked gas stalled out and even when they worked the 305 dog motor with a quadrajunk barely got 10mpg. People want a car that runs not a piece of shit you can polish all day and never get out of the garage....
Love it! The caddy is pretty strong. I actually expected it to be more torque biased than the Buick but then again these are ported heads versus non so that makes a difference.
That motor loved that compression increase! Wonder if that could be run conservatively with 93 octane gas!
put it on e85
That's a big maybe. You might have to cut some timing but the gain is power the 99% of the time you're not at wot will be worth it. It will also idle way better.
If it was put together for this and had things like positive deck pistons, 035 or less quench clearance and polished chambers and piston tops it would probably run no problem with a 160° thermostat. At the drags or even doing pulls on the street it would be fine. If you put it in a one ton pickup and tried to pull a trailer up a grade for miles, you'll run into issues pretty fast. Hot rod built an 11 to one all iron small block fifteen years ago that didn't pick up any power with fuel above 87 octane. It can be done.
👍
I doubt i tried 11 to 1 on an iron headed engine and that was pushing it
I used to be pretty good with Q-Jet's.
The first thing I did was to have my buddy TIG weld the leaky plugs in the bottom of the float bowl, then start massaging the jets and metering rods and adjusting the secondary air valves. Way more reliable than the Holly's with the old power valves that almost always needed replacing after a backfire.
This really makes me want to go with the old school Cadillac swap instead of the LS swap in my 84 El Camino.
Cad 500 parts dot com has the mounts. Bolts right into g bodies. I've been wanting a cad powered g body for years.
Maximum Torque Specialties in MA had a kit to drop a 1970 500 into a Malibu of that era. They ran 11's without modifying the 400 hp engine. Before the 502 Chevy was cheap enough to buy used at swap meets, a Cad was the secret for Chevy/GMC pickup trucks. Buy one at the junkyard, get the 425 single plane intake, Chevy or Ford 429 header tubes welded onto an aftermarket flange, and don't worry about the low compression--you had a beast for towing, with diesel like torque off idle.
Nowadays, of course, you can pick up a motorhome 454, it won't be sludged with motoroil like a 1970's engine, and make decent power that shocks the LS fanbois who think anything older than them must suck.
Q.m
I run the small heads on a 75 short block for almost 15 years. No issues. Stock rockers too. Very precise machining on engine is key.
I've used Qjets several times. That sound as the secondary's start gulping is priceless. And the dependability beats holley's hands down. I only did Holley carbs for extreme uses. That's where they shined.
I’ve worked on most all carburetors and modified ones , I’ll take the Quadrajet every time.! Less parts and it can be taken apart while it’s still mounted on the engine… never been a Holly fan to many issues with them ( but they do have a broader cfm flow ) plus when on a 4x4 in various terrain they cut out unless you buy the float springs which will fail after a period of time.. Q-Jet all the way.!!!!
Richard...i just love the Other Guys ...500inch Caddys ..Big 460 Fords...Cant wait to see what kiind of power the Caddy will make with the single plane intake and the Holley Carb...this is Hot Rodding at its Finest ..👍❤🇺🇸
Children, can you say 'Cadillac'?
Man Richard this is some fantastic stuff your putting out. Much respect to Cad company guys for going against the grain and building real performance parts for lovers of the Cadillac motor.
This motor looks like it can be a budget build competitor to the Chevy 502 BB?? The Cadillac bolts onto a TH 400 ?
No way
Yup. I switched from a TH400 to a 700r4 for that additional gear.
They came with a TH400 from the factory, just with an extremely long (somewhere in the 14" range) tailshaft. Nice part is BOP TH400s are alot easier to come by for cheap than chevy versions.
@@calebdean2440 TH400 and TH425.
Not a competitor.. a 454 has 92% of the CID of a 500 cad and zillions more head choices at the junkyard. 454 + junkyard heads + cam over 500 cad every day of the week.. much cheaper n better.
I love this always wanted to hot rod a caddy I knew the HP was in these motors. Just think 6-71 roots. Or no.2 crazy man..keep it up
Nothing like the howl of a Q Jet secondaries, I have enjoyed that sound since being a teenager in the 70's. I put a 500 Caddy from a 70 Eldo in my lifted 35" tired Suburban, the hardest part was rebuilding a Caddy transmission with a short output shaft for the transfer case. Engine was box stock and ran MUCH better than the 350 I pulled out, with 4.56 gears it was a beast off road.
Hi,
Need 'O2 ' sensors in each exhaust port . on the ' Q-JET , Let the secondary butterflies open past 90* decrees to put more fuel to the front
Cylinders . Check fuel pressure @ the fuel inlet on the Q-JET To Prevent A lean condition .
Very cool info about an elephant motor. This has been a cool series! Boost boost boost!!!
The rear bolt on the intake is awesome fun. No really the caddy motor is the best.
As an avid enthusiast I find it puzzling that most magazine and video tests will give results of their findings with great detail but in my mind forget a very important one,, Fuel Octane used to get the results without detonation and how much total timing was used to get there on each engine. Basics in my mind. I would also like to see how much power I can get with pump piss fuel like you have in CA on a milder engine or the Cadillac 500 here but there is no info. Not all street guys have the luxury of race gas to mix in. Love your channel and very interesting content. Subscribed.
ALL THE INITIAL TESTING WAS RUN ON 91 PUMP GAS UNTIL WE ADDED THE HIGH COMPRESSION-i WOULD NOT RUN THAT ON PUMP GAS-MAYBE E85 THOUGH
@@richardholdener1727 Thanks for the reply. I think it would be very informative to list what fuel you use on any test of anything. If you did you will be one of the very few. What fuel did you run on the high compression 500 caddie engine then?
An incredible amount of info in short vid at shop that specializes in the caddy engine , what could be better , you’re spoiling us Richard .
Is it possible to see the brake specific fuel consumption?
Have any Q-Jet guys tried using a Model #17085213 from a 1985-88 or so one ton Chevy pickup? This is a non-electronic carb with more adjustments than almost any other Q-jet. Without pulling the air horn you can adjust both upper limit and lower limit travel on the primary metering rods. There is also an adjustable air bleed in the secondary circuit, under a brass plug on the back of the carb. There is also the usual spring tension adjustment on the secondary air valve as well as secondary metering rod and hanger adjustments. So this carb can be fine tuned much quicker and easier than a Holley!
The best anything I’ve watched during this quarantine I’m so excited with these videos Cadillac!
Glad you like them!
Dam you Richard. You are telling the world how great these 500 cubic inch Cadillacs are. The prices on them are going to skyrocket and the boneyards will be picked dry.
Welcome to the Richard Holdner EDM dance party! Oh and Richard will be doing some Dyno testing as well.
Qjets are a great carb for everyday driving. If it wasn't for the heak soak problem, they'd be the perfect street carb.
The Holley (and Holley style) and Q Jet are the only carbs I ever run. Can't wait to see the next video. I'll find it eventually..
I run an 800cfm q jet on my 460 works great, best carb I've ever had. The drivability is supreme.
I run a 800 cfm Quadrajet off a 73 or 74 DeVille Cadillac 500 on my 30 over 11 to 1 compression 1967 425 olds . I rebuilt the Quadrajet I didn't even have to mess with the primary or secondary metering rods. The only thing I had to do is adjust the idle mixture screws runs like a top I'll take a Quadrajet over a Holley any day. ;)
Those small chamber heads didnt have piston to valve clearance issues with the 75 shortblocks pistons?
In the 60’s they had leaded premium fuel at the pump . The 72cc heads were on 472” motors . 472s were more common.
not just on the 472s
The 500 from 70-73 had the 76cc head as well.
Unreal how balanced and smooth this engine is .
.
All that extra compression needs is more camshaft to bleed off the extra pressure. Either that or change to E85 or methanol.
I get the feeling that needs to be made into a shirt.... "Who wants to see a bigger cam shaft?"
Yes please
"Who wants to see my bigger camshaft?"
Who wants to see my camshaft with longer duration.
@@axleratio this one wins!! Hands down. Lol
lol - SIZE IS everything...
Richard are your camshafts available yet? If so do you have a link to purchase? Plan to supercharge have changed sold it after all your turbo info.
no sir
Richard Holdener when? Or where can I find your secret specs to order or have custom made?
awesom vid, well done Richard and team, keep'em coming
*PLEASE DO A 403 OLDS!!* I have a 79 trans am and would love for you to do a 403 and Big Bang it I mean come on it’s the biggest small block! 😁
Olds stuff (even more than Pontiac) is rarely found, at least valuable/accurate content. Bill Travato did a bada$$ turbo Olds from a 350 diesel block. If anyone could pull it off its Richard. It'd make a Great addition in "the other guys" series though
I do like 6.6L Trans Ams
@@robertmacpeek424 Trovato also ran his Starfire with Nitrous Oxide I believe .. It went high 7s IIRC..
@@richardholdener1727 I doubt that anyone cares but I put a 403 olds in my 69 cutlass and compared it to the 350 olds that came out of it on my channel
Hard to see but I think the secondary air valve wasn't opening enough. I'm guessing they will loosen up the tension on it to provide more air and fuel lifting the metering rods out of the orifices and maybe a metering rod change or a metering rod hanger change also. Maybe some other mods requiring the top to come off. Might have to change the secondary throttle blade angle also
I probably missed the question when you started the 500 CI tests but I would like to know the weight of this motor with all the stock cast iron head's and intake?? Did you even consider weighing the motor?? Thanks Richard.
less than BBC-more than a SBC
@@richardholdener1727 Ummm Ok.
The length of your videos are perfect.
Big fan of the Q jet. The problem with the q-jet is the aftermarket doesn't care for it. They think it's difficult and hard to work on. So intake manifold companies don't bother to make much over a 5500 RPM manifold for them
The big cam and ported heads, is that considered a stage 2 engine?
My question, for a fair and direct comparison between the Quadrajet and the Holley, should they not have been the same cfm rating?
Love the QJet Richard. That Sound!
I used to run the q-jets on my old Chevy trucks for the sound alone. The performance gains from other carbs couldn't win me over. I thought the q-jet performance was really good anyhow. I always had success with the q-jet
Well I'll tell you a story. Had a 79 firebird 400 BB, mild cam, elderbrock intake, long tube headers. Had a jetted 800 quadrojet on it my dad tuned. It rocked with the quadrojet. Put a 780 double pump on it and my dad told me it would slow down with Holley. Sure as crap I lost 60 hp or more with the holley. Took it off put back on quadrojet.
Quadrajet had a lot of cfm for a stock carb. Depends what holley you use.
Very cool! I should make a response video to this! You always put up awesome content!
Q-Jets are good carbs till they fall apart inside, or the throttle shafts wear out. My heartburn with them was more associated with the stock, low riser, iron intake manifold that it sat on.
I remember a few non--car enthusiasts back in the 70s that swapped their defective Q-Jets in their Impalas, etc. with the new Holley spreadbore replacement carb that came out. And they were happy.
nothing wrong wilt a Q-jet if you how to work on them, never seen a Holley spread bore or Holley used on a street engine that would would run as well on a automatic car unless it had a high stall converter, the air valve and vacuum dash pod adjusted right will let you leave without bogging like holley's especially on small ci engines and heavy cars.
Qjet fan here, what secondary needles and hanger did you use?
Great video. How much $$ for a crate motor?
I have always loved a quadrajet. Get plenty of cfm for power and kick out excellent fuel mileage as long as you dont get in the secondaries. Ended up running a 780 cfm quadrajet on a 72 318 Chrysler I rebuilt. Way better than the thermoquads or Holley's for a daily driver in my opinion.
Richard what brand lifters were the bad ones? They look like power products brand.
it was not a bad brand of lifters-it was my fault
Thanks for the reply
What octane and timing were you at with the 12 to 1 run?
33 degrees and race fuel (110 Torco)
Does the Caddy have the same bellhousing bolt pattern as Pontiac/Olds/ Buick?
'Cadillac'. And yes, Chevrolet is by itself. All other GMs are alike.
@@michaelangelo8001 Thanks. Its been decades since I've had a Caddy engine out.
@@merylpelosi8485 "Cadillac".
You should contact Justin minahan he runs a Nostalgia dragster in the west coast Nostalgia drag Association known as ANRA. Copper Cadillac, its a bad ass ride
So amazing!!! Rich, Courtney. You guys are amazing. Thanks again. 20 likes.
Thanks again!
Something about a Holley carb on a Caddie goes to gather like peanut butter and sauerkraut. This engine is a BLVD beast. Sounds funny on the Dyno. Were most engine are just coming to life, this thing is done with some very impressive numbers.
Great Show !! Are the pistons stock , overbored ? Forged ? Stock pistons pretty strong ! 70 Eldo Cam @ 400 h.p. stock !!! Use Big Ford dual quad intake w/ Adapters That Eng. WANTS MORE Throttle Plate Area Pair OF 660,s or bigger if it will stay clean. IF Good Parts ARE in it Raise that RPM. Limit ! That Combo Ought to Do Over 600 HP. Thanks .
it had forged rods and pistons-and went well over 600
Great video! What exactly is the weak link, or links, on these engines, rods, oiling system, crank? Sounds like it’s just starting to get happy at 5000 lol.
rocker arms
Is something wrong with the current lot of hydraulic lifters, seems a lot more issues with them than in the past. Has the quality been reduced. The only issues you use to see was ‘pump up’ and loss of valve control over 5000rpm?
Made in China...
Michael Angelo I guessed that, but who is going to start paying for rebuilding engines destroyed by hydraulic lifters that have lost their guts.
We need to name and shame companies that sell sub standard parts, more so us backyard engine builders with low budgets don’t loose out.
@@vintagetintrader1062 Yes, I agree.
You need to get together with Uncle Tony's Garage. The two best tech channels on the internet
Lol... He's so far ahead of Tony...
@@michaelangelo8001 I don't think that's quite true. They do two different things. I think.of Richard as the lab tech, and Tony as the field guy.
Don't forget, Tony has a history in this world that goes back almost 40 years. He.must be doing something right.
@@ericlandstrom6155 I'm not putting anyone down, but I have more "history" than either of them.
When I saw Richard's first video attempts, I was disgusted, frankly. He looked an acted like an arrogant, know-nothing, baldheaded jerkoff.
But now that he's dropped the fake act, and started putting real meat and potatoes on the table, I can see that the guy actually has an incredible amount of experience in comparison to your average internet wannabees.
Tony knows the ordinary things that all of us with any experience with cars already know, but Richard takes us into a world that 99% of us could never afford to experience.
Dyno time is VERY expensive, and most people in this audience can not afford it. Everytime you watch one of these videos, it's like he is just handing you money.
Tony bores me, I know lots of people like him, personally. But the information that Richard provides is on a completely different level.
you got all that from a video?
@@richardholdener1727 Many videos.
This is motor I want to put in a 32 ford . Tired of seeing the small blocks . A 450 hp 550 torque cad motor in a 32 would do the job nice . I would guess 11 second quarter mile times?
Just put it in Drive and stab the gas.......LOL
its a wide engine to toss in that engine bay (in the day, folks preferred the Buick nailhead on Model A's due to the narrow width) and there's the length of the front water/oil pump and filter, but you'll certainly want highway gears, maybe even a Buick two speed to kill launch torque. Otherwise you'll do 11 seconds b/c you're blowing the tires away at launch.
Of course, a Ford in a Ford isn't a bad deal, either. A low deck Windsor is nice and light, or a crate 427 cid tall deck Windsor would have all that torque you want and run EFI cheaply, too.
Haha try like 9s 450 horse and 550 ft lbs of torque will rocket anything especially since nearly 500ft lbs comes in at 2k rpm
@@tedteddy2293 that's what made them such a great engine in a brick nosed Chevy pickup you used to pick up cheap. All that room in the engine compartment for 'em with diesel-like torque. And Chevy BB headers for those slabside trucks could be cut to fit the Caddy.
Blower?
richard, can you do graphs that show the comparison to the previous run. so we can see changes in the shape of the curve as well as the outright difference.
All these swaps are with flat teppet? New lifters and break in each time? Love the BPO and Caddy tests. It was my world for a time. A few 350 Rocket cars. Rev them high!
Cadillac...
@@michaelangelo8001 really?
@@ericbengtson3490 I despise Yankees that are too lazy and ignorant to fully pronounce proper nouns.
yes on flat-tappets, no on break in (reuse lifters)
@@michaelangelo8001 Chill Mike, not hurting anyone.
At some point. Could you show a comparison of a 248 cam on a 350 to this 500? In relation, tbis 500 is acting like a 350 with a 220 cam.!!!
On the dyno it's really hard to quantify it. Youre only looking at power at wide open throttle. If you take a new Ls2 crate engine and put the biggest cam you can fit to the valves and take another an put the highest flowing largest port heads on it, they will have similar power curves. When you start to compare these at part throttle you will get some substantial differences. If the factory or ported heads had huge port volumes, it would really cripple the low end torque with the bigger camshaft especially at part throttle.
do you think biggest head with a stock cam will make as much as the biggest cam (p-V) with a stock head?
@@richardholdener1727 that depends. An ls2 will gain somewhere north of 90hp with a max effort cam swap, and a stock cammed ls2 will gain about 45 with max effort heads. If you do the same comparison on an ls3 it's not even close, the factory heads are too good and max effort porting doesn't do too much. What if you had an L78, it's got pretty aggressive cam timing and pretty good heads but the huge dome on the piston might cut your fun early, and the factory heads don't flow over 300cfm until 700 lift, where a modern set of cnc ported heads might make lots of power with the factory camshaft. That's why I specified ls2. I don't know what the cam is like in this Cad stock but probably less than 190@050 and around 400 lift. It doesnt matter what head you put on it at that point, not a lot will happen.
My point is with an ls2 the shape of the curve will be similar. My point also stands that putting a cam with 600 lift and 240@050 might work really good at even 2500rpm on the dyno with no manifold vacuum, that camshaft is going to cause issues at 1500rpm and 15" of vacuum.
I can't find the port volumes of these heads but they look like they are in the 240-260cc range. Really small for the 514 cubes they are tasked with feeding.
Do you think you could overcam a 500 inch ls stroker with stock ls1 heads, or do you think that every camshaft up to the big cam here you put in will add power everywhere when you test it on the dyno?
Richard,
Since you are running other guys motors. Maybe when you get to boosting the 500 you could do an exhaust comparison? Stock cast manifolds, vs. logs, vs. short turbo headers, vs. long tubes?
Love the high speed video,thanks.
Note that the power is at very low RPMs in comparison to an LS, etcetera.
What kind of valve gear are they running on this engine... modified Buick, early Ford?
You could do a really nice cnc chamber on those small chamber heads and drop comp to around 10-10.5:1 and run it on pump fuel. Might get close on power.