First-Ever Variable Valve Timing Direct-Injected 8.1L Engine Unveiled
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- เผยแพร่เมื่อ 27 ก.ย. 2024
- Today we're going to get into some of that detail and Larry Hofer will explain how he's has designed and engineered these one-of-a-kind components for his 8.1 liter direct injection cylinder heads and how he incorporated variable valve timing onto a GM Big Block. The previous video introduced how Larry is converting his new C8 Corvette to a Big block 8.1L powerplant.
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50 years ago I'd be reading about this in Hot Rod magazine ,where lots of innovative things appeared each month. ,not watching it on a PC. 😁😁
Brian Lohnes has lots of vintage / old time research from the day
lol today the "brains" at hot rod dont think a car like this is worth looking at.
Great how technology works 😅
@@samstewart4807 Yeah thats why they went quarterly.
I just threw out all my street machine mags, etc, from the 80,s . Magazines were the original internet for getting info . Cheers
Thats Larry Hofer, owner of the Corvette Shop in San Diego - cutting edge stuff these guys are doing if they cast and machine their own heads! These guys are wicked-smart!
Don Taylor is a badass, more of him please!
YES!!!
Don Taylor is a good friend of Larry. I believe they wrote several books back in the day.
I am 35 years old my first car was a 1969 Camaro it was 38 when I was 16 and you documenting these legends and their engineophile innovations is very much appreciated.
Your welcome!
Just got off the phone with Larry talking about my 2 boat motors that he built. Crazy he spent a half an hour chatting about options for freshening up. Trying to meet up in Havasu for desert storm
That’s awesome! Larry is a nice guys!
I always was an LS guy, but more and more I become a big block fan.
Anytime i watch these the amount of knowledge in everyones head absolutely blows my mind. To be around these dudes doing/learning the things they do is probably the best job in the world
Awesome work, always wondered when someone would go direct injection on a big block, can’t wait to see more on this!
Do more on this engine conversion please, this is incredibly insightful.
MORE OF THIS! I don't understand why so many Chevy/GM guys delete VVT and/or DI instead of integrating it properly into a build. There's SO much power to be found!
because most guys just throw in an aggressive top end cam? They're not looking for low end and driveability. Very simple
@@THESLlCK it goes far beyond that. With a properly equipped VVT cam, you can make more power EVERYWHERE. And everybody wants that.
@@spdcrzy no, not everybody wants that, very clearly.
@@THESLlCK they're lazy. -_- Nobody seems to want to do max effort N/A motors anymore that actually have to be engineered properly.
@@spdcrzy what?? No dude, NA motors never had it better. theres 1000hp small blocks on the street now man. VVT isn't useful for a max efffort race car lol, which this is not
Cant wait to see the C8 big block! So wild to see the custom head work.
Bro…your inner circle is First Class OG horsepower junkies
On a whole different level. In a whole different solar system. Mind blowing and amazing.
I know, right? Some pretty cool stuff happening at a couple different shops here in San Diego.
There is being a mechanic and there is being an egineer. This guy is an engineer!
I'm sure this guy has plenty of money. But still not above using a shopping cart to hold a Big Block research engine.
Love the ingenuity.
Keep up the good videos.
Yep, that’s because Larry ends up with abandoned shopping carts in the alley so he makes good use of them!
This is what happens when old school gear head meets a DoD budget! LOL Incredible!
Great piece, thanks. When Don is expounding please try not to interrupt.
wow this is so awesome, look forward to the next video of the 8.1 C8
Coming soon!
I would have loved to have this gentleman as my teacher.
That guy is a damn genius... That is some slick ingenuity!! I have an 8.1 in a Suburban I want to save and build when the truck goes to ShIte from rust in time.... This is some exciting stuff to ponder
Mercury Marine 496 HO UPGRADE!!!! Hell yes!!!!
This video seemed to go by in about two minutes when you said “well this is it for this video” I was stunned it was over so fast! Please video assembly of the 8.1 I love this stuff and the 62 Corvette is beautiful I’m one year older than it. Thanks for the video.
Glad you enjoyed it!
Thank Larry and thank you for your time and this video. I just love this type of content.
I love guys like this.He has a deep understanding beyond the average tech nerd. I really enjoyed the posting.
Can't wait for the next video where it all goes together. Thanks Greg for these great videos from these great guys!
👍💪✌
Glad you like them! Thank you
I would love to hang out with him and nerd out on this build.
Simply amazing 🎉. Please stay with this until the end 🙏
my goodness more incredible car stuff ur channel should have thousands and thousannds more subs truly 1 of the best channels ever thank you for sharing all this auto honey with us out here
Wow, thanks! I wish I had more subscribers and viewers. I just don’t think I’m hitting the TH-cam algorithm frequently enough to attract more subscribers.
im loving this series
Thank you
Looking forward to the next episode. Thanks.
I always thought GM would put more RD on the 8.1. Then, trying to get so much out of the 6.0 or 6.2.
Like ford with the godzilla motor.
Big Block Vtech...now this guy has me wondering what it would be like to have a high revving, high comp big block with those cam phasers on.
Direct injection big block ❤
The 2 things everyone deletes when they build a modern engine. This guy said nope, he loves it, and wanted to add it to a engine without it.
I'm the same... I always go for maximum torque at lowest rpm possible with the hard-built(the motor itself)... and get the horsepower at higher rpm with some power adder if more is needed. VVT and DI are key for low rpm torque and power.. look the difference between a Ls 5.3 gen 4 vs lt 5.3 gen 5. That fuel cooling down the pistons can make it for a much higher compression and make a whole lot more power ***without the need for higher octane***
Mind blowing what he’s doing
Awesome. Direct injection will probably add 50hp at least if compression is bumped up.
I’m still absolutely loving this DI big block build I’ve been wanting to see someone with the know how to do it and it looks like I’m in luck.
When I grow up I won't to be just like this man this is the stuff I love eat breath live for I just love it R & D it's so fascinating for me!!
I remember reading about Mickey Thompson doing this to a small Chevy in the 60's
LT engines have unique chambers and top of piston shape, I wonder if that was resembled.?
If his traditional 8.1’s make 525, I wonder what this version will make.
Imagine making 100 hp per liter on one of these
This is awesome brother!!!
He is a brilliant man i seen other things he did. Not sure if it was you who posted it or not thow
This is so cool! Keep em’ coming!
Thanks! Will do!
This is seriously fascinating stuff! I'd love to hear why start with an 8.1 and not the PSI 8.8?
The 8-1, looks alot like a LS anyway. I'm surprised no one is using the truck engines more, the 6.6 or what ever, the gas option for 1 ton and maybe a bit larger trucks , not that familiar. I wish they would build a basically big block LS, a wider bore spacing, taller deck height, possibly a 1" taller deck a spacing to allow 4.250-4.560 bore and 4.300-4.750 stroke up to 604cid with direct injection and port injection, use the port injection for cold start enrichment. And full throttle high rpm. Build a SS-3500 with a big supercharger 10 speed transmission, 604 CID. 20" aluminum rims built to haul and pull toy trailers. Basically a ss454/typhoon style modern truck in dually and single. Making 855TQ and 760hp on 89 octane , and on E85 and the 😮WOW! Tune 990tq, 1100hp stock with tune and exhaust upgrade, and blower pulley, with factory dual 3.5" or 5" single single , stock exhaust. This would be an awesome truck no one could afford, it could also be a hybrid, with a 80-120kw motor in a transfer case like gear box on the transmission, or on the transfer case in 4x4 trucks with a 60 kwh battery between frame rails. With plug in charger and re gen and charge as driving , .5%-15% of the power goes to charging driver set> and Regen or when the brakes are tapped the Regen starts even when driving non ev. Also the motor and engine work together for just under 2000 TQ, about 1400 HP, with optional additional over/under drive in the transfer case, to get roughly 50% reduction and 20% additional over drive, of shift from 1:1 to +.20:1while driving just like a gear change , or change in each gear, making a 10 speed into a 20 speed, or just a 11speed. The 20 ratios works best during slow acceleration. Allow full speed good economy, with smooth gear changes. Similar to a variable ratio or CVT transmission, this is something gm should build! In 4500 also with pickup bed and 4-door . Sorry to dream and ramble!!
Love it , great content. Thank you !!!!
Great stuff again Greg! Thanks!! 👍👍
My pleasure! Glad you are enjoying it!
Very interesting indeed, please continue Greg, Thanks
I always wanted to see this done to a gen 1 small block
Great content well done
Greg, I have an idea for you. You mentioned you were off this week. I'm going to assume that to mean this week but I don't know when this was recorded. If Larry would be up for it I would love a live question and answer session. I would love to ask questions about the process of designing and having my own castings made. I understand that he is probably very busy and doesn't have time to sit around. However if these type of people don't share their knowledge to other generations it will die with them and eventually so will the car culture/hobby. I have a lot of respect for the men that you video and want to say thank you for taking the time to do so.
It's beyond me why GM didn't put direct injection on the 8.1 and continue using it for the hd trucks instead of the 6.0 or the 6.6 (gas).
It was not meeting cafe standard variable cam timing and dod on ls/lt allowed smaller engines to make more efficient power with technology to meet cafe standards
VCT is amazing....
Awesome Sauce
What a man
nice, thanks for making these (not a spam underpants thanks but a real one)
big block direct.. very deserving. I am curious of durability on that heat angle. I like the gm history. I still run a spider injected truck as if it was a modern marvel. It did everything I had guessed it would back in 1996. The first injection swap..390k miles, at 26 years. and it was my fault I broke it.
Is it possible to give a more detailed explanation of the direct injection system, the wiring, the timing and ecu management of the whole system?
@@reginaldmorton2162 yes we can do some of that in the next video
What are the HP/Torque numbers. "Yes"
They did it this way to stay in contact with stock computer now that global b can tune c8 I would have deleted direct injection or had both like the zl1 or 18 up mustang gt port with direct
You made big deck engine from perfect big deck man I like it really
How much cost like this engine???
Great and interesting
Wow. Thanks.
Using the injectors to cool the air on the blower 'vette,.... Just like a carbed turbo. Nice!
When he says 'computer', is he talking a Factory ECM? If this thing works, should we expect GM to copy it? 😂
NA, a big block C8 is going to be like driving the big GT-40 back in the '60's. Add some boost, you'll be hunting Veyron's at 1/10th the price!!!
Even with the LT small block and some turbos, you’ll be hunting Veyrons on a budget.
Did you figure out how to make a DUHC kit, yet?
so it could have one intake cam & one exhaust cam, with independent timing adjustment
What's the point in the mechanical pump lobe when you are running efi? Since there isn't any mechanical pump that puts out 58psi.
Common rail high pressure direct injection is close to 3000psi at the injector - the lift pump in the tank will be around 40-50psi Also standard fuel injectors have 13-14 Ohms where as these high pressure injectors are at 1.5 Ohms. It’s a different animal! The cam lobe drives the high pressure pump which is in the valley under the intake manifold.
Do you not know what direct injection is ?
@@GregQuirin thanks for the info. I'm still trying to learn everything an didn't know that.
@@jkfonyi I understand what it is but not how it works
The 8.1 uses the same 18726543 firing order as the LS/LT engines. Do you maintain the same firing order or go back to 18436572?
Let him do the talking
Yeah, he's a bit interruptive and is obviously leagues less knowledgeable. I couldn't believe it when he asked about a solenoid for the oil feed off the camshaft and was shocked that fuel pumping could be accomplished mechanically.
did leave the big block with the stock cam and the stock injectors? if you did , this comparison is flawed.
never liked direct injection = fuel flow cleans up ports and adds a cooling affect on valve gear ! = just look at the dirt on street direct injectors ! = great for planes and flying upside down ! but take a lot more to change my mind on this !
mustang gt got both after 18+ 16 injectors
Cool
badass
Mechanical variable valve timingThat's run by carburetor with no computers you might want to consider that anyway great video
I wonder how much my old LS-6 would gain from this kinda upgrade..
Meanwhile my dumbass is over here with a Dremel trying to guesstimate a port and polish without any idea what volumetric efficiency and port matching is lol
I wish you had posted a direct link to buy his book
Here you go I would check Amazon as well www.americanbookwarehouse.com/4536363/
Go on Google, amazon or Car-tech. they all have it.
@@GregQuirin i bought the book and posted the link
Do you have flow numbers?
No one will ever see this but can I get a blueprint / spec sheet for the dimensions use for the injector bung?
Hi what do you mean by injector bung
The cutter dimensions, i can send you those.
@@larryhofer2266 if you can send me the dimensions that would be awesome, my contact email is in my channels details at the bottom.
Is thet emeila hartfords camaro I see
wow
"Factory supercharger" my ass.
Someone call me out for my ignorance, but why havent we made a standalone ecu that can control direct injectors yet? I know holley has a version for gen v engines but im supprised more people havent adopted it yet
GM designed the gen V heads *around* the DI system. I don't think retrofitting the BBC is a great idea. Don't forget the catch can! The 8100 is notorious for a bad PCV system.
👍
Seems like alot of time and money for 30 hp (495 to 525),
is the book available as a free e-book
But why what’s the goal is it more than 600hp na ?
Thanks for the video Greg but maybe a little steadier with the camera and not bouncing around so much it makes me a little seasick
I find it hard to understand why? why would you go to all this trouble just to make it "work" with the stock ecu. intake cam and exhaust will make the same power in an 8.1..... or really close to the same power. most people want to go the other way and go to port injection. Are you going to run both types of injection, and will it have problems gumming up the intake valves? I'm really curious how much more efficient the engine is maybe that is what will make it worth it. I would have just changed or tuned the ecu.... especially for the vvt. it would have been way easier to change injector drivers and turn off the vvt and keep the stock ecu.
That's Emilia's car.
If they need a driver for anything salt flats top speed I'm your man I've got Factory traction control built in my right foot!! I will sine my life away I just want to drive !! Red hat is all I want!
They're "detuned" because the stock hypereutectic pistons get "unhappy" at 500+ hp.
And as for the "your design" cylinder head that's as much bullshit as this engine "unveiling".
How are you actually retaining those injectors IN the "your design" heads and are those injectors properly "clocked" in the combustion chamber so the spray pattern is correct?
LS engines are "wedge" headed. Splayed valve BBC chambers have entirely different "architecture".
As for "that intake" that POS looks like somebody cast a "Godzilla" intake with that dumbass throttle body angle. Did you get "your" VVT from a Godzilla too?
Hell maybe the "computer" and the injectors it "recognizes" are Godzilla "big-block" parts too.
Regardless that POS is miles from running much less "tuned".
IT WOULD BE A LOT BETTER INTERVIEW IF THE MODERATOR, WOULD QUIT TALKING OVER THE PERSON BEING INTERVIEWED,
I was happy with it.
Sheesh man…
Click bait,dont bother,still not in it
Click bait,dont bother
Hard pass on VVT!
Would have been first choice but know if the computer will let me. so here we go.
VVT when done right, and not by a mass corporation can have some huge Advantages.
@@josefrobbins8781 Dealing with and issue on a 2.4 Ecotech right now and it's a real ball buster. Same as with any other corporate VVT setup... While it is nice to have the fuel economy it provides, the way they did them leads to nothing but huge issues if maintenance is not done religiously.
325hp from 8.1L up to 525hp from 8.1L is still pathetic. Its no wonder the V8 scene has kept going so long they were so inefficient from he factory you can make big gains from bolt ons. but still not realize you engine is still pretty average.
That's without the direct injection and variable cam timing
It's 65hp per liter which is quite comparable to many other stock engines both 2 and 4 valves.
Also Chevys v8s are proven to make over 3hp per CI or 180hp per liter in racing configuration NA.
Which is quite good and better than many full race 4 cylinder engines I have seen.
Especially if you compare them with other 60-70 year old engine designs.
It's a regular pump gas engine for a heavy vehicle, made to haul and tow heavy loads. It's made for off idle instant torque, which it does VERY well.
The later 8.1 made 360HP and 450 ft/lb, and would make 450HP and 550 ft/lb with a tune.
It will make over 550 with headers, a cam, a throttle body, and intake mods. And it will STILL make massive torque, right off idle.
If you want a big block to make HP, and not low speed torque, you can make 750HP on pump gas with a 496 (8.1) but it won't be an ideal engine for a 7500# crew cab pick up that pulls a 20,000# trailer anymore.
Peak numbers are meaningless if the power band is 1,000 RPM wide. How much power a NA engine can make is a hard limit based on CID. The question is at what RPM do you want the power to be and where in the RPM range are you OK with losing power. ( RE a stock motor can idle at 700 RPM and pull from there where as a high number engine can't make enough power to overcome internal friction below 1,500 RPM. ) Also note that factory motors are detuned so they live for 150,000 miles. There is no way your high HP motor can survive that long.
Considering RPM, drivability and HP per cubic inch naturally aspirated, still doing ok.
the computer is the question we still don't have a very good answer to.
With this much work, why not modify the new 632 insted of a tiny 496?
Great video thanks for sharing that’s genius I was wondering how they got oil to the cam for it all to operate
You are welcome!