Big Block 8.1L - C8 Corvette Engine Swap Update “Will it Run?

Larry Hofer is a notable figure in the Corvette community, recognized for his innovative work and expertise in modifying and enhancing Corvette models. He operates a specialized Corvette shop, focusing on high-performance modifications and custom builds. Hofer's shop is renowned for undertaking unique and challenging projects, such as the groundbreaking conversion of a C8 Corvette with a massive 8.1-liter direct injection big block engine. His work exemplifies a deep understanding of automotive engineering and a commitment to pushing the limits of what Corvette platforms can achieve. Additionally, Larry is a published author and has written several automotive technical manuals over the last 30 years, further establishing his authority in the field. He also offers a high-performance line of 8.1L cylinder heads, intake system kits, and other products for GM big blocks through his business Raylar Engineering. For more information, visit
Raylar Engineering (www.raylarengineering.com/).

[@nickb289]

What will we do when men like Larry are gone. They don’t ask why, they don’t think about limitation, they invent and create what others can’t imagine.

[@jmooch59]

I will continue to carry the torch

[@lukehoza9571]

Come on dude what sort of attitude is that? Get out in the garage and do something

[@4familyman]

Plenty of us doing interesting stuff and documenting it. Also, you can too! Just pick up a cheap welder and a cutoff wheel

[@andrewmontgomery1763]

I mean, there’s a couple young dudes who made a 4V Ford 6.8L V10 and are putting it in a modern Lincoln… sooooo yeah people are still (and undoubtedly will continue) to do really incredible projects.

[@JohnnyDanger36963]

he's not woke.

[@texasmetal8513]

This by far the most exciting gear head project I've seen in a while

[@DIY-V12]

There is no substitute for knowledge and experience combined with determination. Great progress.

[@JW-hm6ou]

Larry is keeping Hot roding alive. Really enjoy seeing this makes me happy. Thanks Larry Hoffer!!!

[@jtb3797]

There is no replacement for displacement. Excited to see this masterpiece on the road!

[@Sergeantgrunt]

Weeelll, yes there is. It's called a TURBO.

[@Ckcdillpickle]

@@Sergeantgrunt So... what about a bigger displacement engine with a turbo...

[@ryanturner8318]

Larry you probably have met or talked with my grandpa Pat Devincent from Ohio. He was a lead engineer for the corvette from the very beginning. He had also worked on designing the fiberglass leaf springs, air bag and a few other things for General Electric since they were originally are a parent company of GM.

[@rjung_ch]

Can't wait to hear it come to life, thanks Greg 👍💪✌

[@GregQuirin]

It has a heartbeat, Live scantool data is present. Larry is having to fix a few high pressure fuel leaks first before attempting to start it up. We will have the cameras rolling.

[@Sandiegosunshine]

Fuel pump power control module is what that is ✅

[@shawnwalker8509]

That right

[@GregQuirin]

Thanks for the info!

[@Flash-FX]

Space Shuttle plumbing and stuff...love it!

[@mohanperformance.enginerd.1308]

I don't get why anyone would want to do this? But its an epic effort. 🏁

[@bobroberts2371]

Check valve in the fuel supply. I'd expect the factory manual to have a theory of operation explaining what it does. I'd expect that the check valve prevents vapor issues during a hot soak.

[@TheWolfMatt]

GM will need another variant of the C8. The "Thumper" edition C8 Corvette. This thing is going to rock.

[@yobringitondown5565]

Hi Greg! Nice meeting you today. It’s Greg, the guy with the 240Z. Can’t wait to see if you guys got that engine running. Waiting.. 🤘🏼👊🏻🙌🏻

[@GregQuirin]

Nice meeting you Greg! We made great progress today on the 8.1 C8 Corvette shortly after you left. I will be posting a video with the news and results here shortly within the next day or two. Stay tuned!

[@FunCityFrenchus]

Thank you for documenting this project. Can't wait to hear that Big Block fire up!

[@thehomelessproject3784]

These guys are old school geniuses they don't make them like this anymore 😮

[@outsider7658]

There was only a limited numbers of guys, not asking "if", it`s possible, but did it anyway. Just sorry there are so few of us left! 🤣 Just a joke!

[@AllSpeed]

this is such a cool build. if he needs more fuel, maybe he can run both direct and port injection like Toyota's D4S injection system.

[@drfoo1957]

Are you going to put ceramic tiles on it for re-entry?

[@scottm7341]

Oh cool, I didn't realize he's the genius behind Rylar.

[@GregQuirin]

Yep that's Larry

[@bobbiduncan3119]

Mr. Larry Hofer looks so much like my dad. My family sent a side profile and we thought it was my father. Looking straight on, you can tell a difference, but wow, that's insane. 😂

[@johnnyrock852]

Dude is awesome! Love someone is still doing this sort of thing, especially in Ca. Now we need a CARB legal version.

[@JoseRivera-ym3wj]

Dummy injectors? I know that there's more potential on that big block if fueling with the direct injection system becomes the limiting factor. I don't know anyone that makes uprated direct injectors for any gas engine. The dummy injectors could be easily used as secondary injectors when more fuel is needed. Plus there's the benefit of having cleaner intake ports and valves, as the gasoline will keep any carbon deposits from accumulating. I know that PCV technology on direct injected engines have improved a lot, but it would be some added insurance in this setup. Maybe a stage 2 phase of this project. This is an amazing engine swap project as is. Can't wait for the other spectrum of C8 engine swap projects: Rob Dahm's four rotor C8 as tribute to the Aerovette concept, which had a four rotor engine.

[@charlesritchel924]

Larry is a fountain of knowledge. Pay attention while you have the time to.

[@TheSwaffordHomestead]

What a huge project! But when it runs, all those hours of work & planning will be worth it! Keep us updated, I want to see this assembled & fired off!

[@joef7406]

Thank you, Greg and Larry, for a glimpse into your fascinating project.

[@johngato737]

Hands down my favorite channel.

[@GregQuirin]

Thank you for your kind words!

[@mcfast52]

If that box at 5:00 is made in Mexico it's to control the spiciness of the tacos!

[@WildEngineering]

4:05 lmfao i love the honesty

[@farmerkevin]

Big block baby!

[@WilliamBurdine]

Can't wait to hear it fire up... I am in La Mesa, so give it a few good revs, I'll be listening !!! LOL

[@mikesmith7447]

Thanks for the update.

[@regsmith7604]

My favorite Corvette color 👉🏽Arctic White😊I can’t wait to hear that 8.1

[@timsgaf]

very cool. Thanks guys.

[@Sleeperdude]

Didn’t expect the F bomb

[@jacobm2625]

That's how you know he's a real one

[@joshjones3408]

Oh my ....😱😱😩😩

[@benrossbach6501]

Dam impressive. Thsnks for sharing

[@fredericrike5974]

Mr. Hofer, for seeing into those dark holes and such, a borescope would be ideal- a tiny camera/light on the end of a flexible semi rigid cable that you stick in the hole and look at the image on a CRT screen or maybe your cell phone. I can't wait to hear this baby roar! Let 'er eat!

[@johnathongulley1146]

Love this build!

[@spdcrzy]

With twin turbos and BOTH direct AND port injectors, this would be a monster. The fact that they were able to integrate so much of the 8.1L is awesome. It's a brilliant approach to today's tuning challenges: change everything about the engine that's ONLY mechanical (like ALL the engine hardware itself), but maintain everything that has an electronic signal for a computer to read - so all the old sensors plug into the new metal. And you can even ensure emissions compliance! Pretty damn cool.

[@CanIbeFrank]

I completely get what he's trying to do by putting a big block and convincing the car it's still stock but it would have been amazing if it was manual swapped. A manual big block c8 would be epic

[@kevinvanneste2500]

I think it's a great idea on paper but where to put the shifter and cables for the link... The computer would be fully independent and all the other stuff you would incounter that is not going to work or be compatible... Sweet idea I would love one

[@jacobm2625]

​@@kevinvanneste2500I feel like you could probably route either cables or hydraulic lines for the shifter almost anywhere you'd need to. An old tr6070 out of a C7 could probably get modified to work in the C8, too. I am not super familiar with the platform, however, so I could be totally wrong.

[@daltonhanleyjr4142]

​@kevinvanneste2500 I think with an adapter plate, he could use the transaxle, shifter, and shifter cables with slight modifications from a Lamborghini Gallardo/Audi R8 since the cars are very similar chassis wise with the C8 Corvette.

[@randoawesomemix9501]

And what manual transaxle that's designed JUST FOR THE C8 would you use?

[@daltonhanleyjr4142]

​@randoawesomemix9501 There isn't a manual transaxle designed for the C8. Hans Juecter, the lead engineer of the C8 said a manual transmission option was never a consideration when designing the C8. So one would have to improvise and create the option from scratch. Using existing parts from other OEM manufacturers and modify to work.

[@herculesinwyoming]

Outstanding!!! ❤

[@geoffhurley8103]

Amazing!! More, please!

[@GregQuirin]

More to come! I promise!

[@8marcrara11]

Very good!! Thank you ⚡️⚡️👍👍

[@rebekahfrench5747]

Engine removal everytime it needs a check up..😂😂

[@ryanb6658]

That’s what you get when you buy one of those cars

[@CanIbeFrank]

Amazing

[@DonCarlos-Medellin]

Super excited. Thanks for sharing. Let’s all hope the rest of the project goes smoothly. 69 year old gear head from San Diego, now expat living life in beautiful Medellin Colombia.

[@lanceneuman9528]

Thanks Greg

[@GregQuirin]

Your welcome!

[@ldtenenoff]

Wow great vid man ur and we r so lucky to have passionante folks whom r just Kool as alll get out thank you for sharing this great american corvette god with us folks! wat a treat

[@williamcornell9744]

But Uncle Larry!! Will it run!!

[@CarHound]

love it

[@joshuaelizabethfoster6276]

At Larry I'm sorry about the summit report I made, sort of...This is a 10000$ kit when your done. I still think you would have had less headaches from people dropping your aluminum heads over those arp studs, then complaining about aluminum chips in the sealing plane and block, if you had simply sold blank heads and offered the head studs as an up sale. More sales at 2000$ reusing stock valves train with a cheap head gasket/stud kit with less troubleshooting. But this is totally what the 8.1l needs to stay current THANK YOU FOR YOUR WORK!

[@lasskinn474]

great honest content man. edit: will the restriction and check valve even out the pressure of fuel going into the direct injection pump? (pressure pulses from the 'low' pressure pump). are they using that pressure in some calculation on the stock efi to calculate what the pressure will be after the high pressure pump?

[@dannymitchell6131]

I love this guy "What in the *** is that?!" Thanks for filming dude.

[@Mattmazz77]

There's nothing like a big block. All the twin turbos and supercharged c8 immediately surprised no 1 has done this yet.

[@RevengeAvenger]

I would absolutely love to visit you guys when I come to California. I'm not a youtuber.. just curious and amazed at yalls abilities.

[@TheJjrjr125]

This is so interesting! Thanks for sharing! I'm curious if there may be any future plans for the original engine?

[@bullast2046]

I’m subbed, as of 4:00 My man

[@cantdriveslo]

Now that's the type of mechanic I would want working on my cars

[@charlesdelaparra5997]

Pretty awesome project and a lot more involved than I could have ever imagined. 2 questions. Is it going to be offered as a swap package for willing customers and will it be cheaper than a Z06?

[@TechScottBrown]

The check-valve is in place because of how the HP pump works it will bleed a small amount of pressure back on the feed line. You will likely need a larger orifice check valve. Maybe check with what the Z06 has?

[@P-J-W-777]

Put a bigger one way valve on that fuel line to get better fuel flow. Like you said they put it there for a reason but you should easily be able to replace it with a bigger valve.

[@beaches2mountains230]

SURE WILL BE NICE HAVING THOSE PORT FUEL INJECTORS WHENEVER THE OWNER GETS USED TO IT AND DECIDES THEIR "BORED" WITH IT LOL..I REALLY THINK ALL DIRECT INJECTION ENGINES SHOULD HAVE PORT INJECTION AS WELL TO AVOID THE CARBON BUILD UP INSIDE THE HEADS AND BACKSIDE OF VALVES..SUPER COOL BUILD AND CANT WAIT !! NOTHING SOUNDS BETTER THAN A BIG BLOCK CHEVY WITH A HEALTHY CAM! AND THIS ENGINE ONLY WEIGHS WHAT 120LBS MORE THAN A LS ?

[@robertphillips3078]

Sensational effort 2 get this Job done . Interesting 2 see how it drives especially around corners with all that xtra weight . If l had that kind of $$$$$ l would have gone 4 a 441 cu inch Windsor 9.5 deck height. With SBF Hemi Heads from Hammerhead Performance. And the ring Dustin @ Whipple Superchargers & beg him 2 re disgn the base of his 3.8 ltr superchargers 2 fit . Obviously 2 make it all work beautifully would be coil near plugs & crank trigger ignition & billet block ,heads , crank, rods , pistons . And dry sumped . The special request 2 whipple would be asking 4 there cupronickle intercooler core ( marine use l know ) but should assist 2 give u big HP & TQ on 93 Octane.

[@masen1458]

My guess for the check valve in the fuel line is for when you shut off the car it keeps fuel pressure at the high pressure pump.

[@user-qi7pf7zg5z]

Personally I would do a 632 bb chevy those 8.1 are heavy. Specifically In a vette. But those 8.1 are torque monsters.

[@jerryl3270]

What about a high pressure relief valve for the return line? I do the same thing on the diesel. On the fuel rail

[@nrakma]

More weight and a higher CG is the formula?

[@rogerrolex6981]

When is it going in the car and when are the shake down runs 😊😊👍👍

[@PederEllefson]

Check valve could be to prevent back flow if an injector fails.

[@aDumtreeF85]

This confirms that there is no replacement for displacement.

[@martinpal1764]

Is there a base line estimated HP for this build?

[@zmanmd1641]

Most GDI engines approach diesels of the same size in maximum torque output, so that will be interesting in how this engine performs. One of the big hurdles with adding power to a C8 is the transmission is limited in how much torque it can accept. There are clutch upgrades and half shaft upgrades used to help this, but the internals of the transmission are the ultimate limit. How much torque will this DI 8.1L make and will the transmission be able to take it?

[@truthbknown8174]

I I really enjoy watching this progress. It does concern me all the parts they do not know what they do or why; particularly the 3/8” fuel check valve. BUT I want to hear it run

[@jimclarke1108]

The only way

[@davidrutledge6033]

The c8 Connan version big block instead of the c4 corvette v12

[@RobertWelchman]

Love the project and absolutely respec the knowledebase here. Dumb question... why not upsize the check valve?

[@xozindustries7451]

Is he going to run a level sensor on the dry sump oil tank?

[@GregQuirin]

Not sure I will find out for the video. thank you

[@Mercmad]

a bit of difference to Granddads old Ford flattie. 😊😊

[@jamesgeorge4874]

It's his project, I cannot imagine taking a 475 Lb aluminum engine out, to put a 600+ lb iron block engine in, weight is a bigger enemy, than power, in a mid-engine high performance car.

[@robertphillips3078]

Am very suprised that the headers aren't jet hot or ceramic coated ....

[@reedjacksonmaccom]

its magic 😂😂😂

[@MartinMcMartin]

That's cool, like an old VW you drop the entire power unit out.

[@davidaarons2488]

First thing I thought was ABS module?? but could be as ya said coolant fan ?? Great progress though, it will be awesome, Thanks

[@Rustynoname]

I wish Gm would make a flat plane high reving big block. lol.. 4.5in stoke - 4.5in bore and figure out a good deck height for perfect rod length and stability.. VVT-DOD-Overhead cam-Direct injection.. 9000+ rpm 572ci lol or a v8 designed like a street bike engine that revs 15k

[@Whance_Chilkins]

A 572ci flat plane V8 would vibrate like crazy at high rpm

[@Rustynoname]

@@Whance_Chilkins can you explain? Most flat plane or high rpm motors use close to same stroke/bore size. You would be taking a 5.5L and upscaling it basically. Why would that vibrate like crazy

[@jareknowak8712]

The weight of the pistons and stroke are way too high for durable 9k rpms. New Ferrari "12Cylindri" is a 9k engine, but it has 6.5L in 12 cylinders.

[@miketaylor6282]

It’s crazy to think some GM engineer thought it was ok to locate wiring harnesses, and control modules in the wheel wells. 04:10 Oh but wait, there’s a splash shield keeping it safe and dry. Come on GM puff, puff pass! 🤦‍♂️🤯😡

[@michellee8369]

🇦🇺

[@RussellCompton-fh3gr]

need video of install is posible

[@RussellCompton-fh3gr]

if its possible

[@GregQuirin]

Video coming soon

[@MovieMuscle]

He's been in and out 8 times so far during this build. To aide in fitment and plumbing etc.

[@stephencurry8552]

Hot Rod magazine is no longer a monthly. Sad.

[@robertphillips3078]

Twin Turbo Charged , how much HP & TQ is he wanting 😂😃😁😀

[@justinwam]

Why???? When you have a 6.2 and a 5.5 to choose from. Whatever keeps you young

[@edmelungeon2239]

Does the 8.1 make 1000 hp? If it doesn't its pretty useless.

[@welshrarebit9238]

If it’s not factory installed it will be riddled with issues

[@Rustynoname]

If it shifts I’ll be mind blown.. those transmissions control modules are bullshit. Glad they are starting to get them figured out tho.

[@jareknowak8712]

Separate control modules are avaliable.

[@CR-xv8wm]

This thing is going to be bad AF!

[@joeyDi8764]

Clickbait...

[@gmcnelly2468]

one hungry mouse and this unnecessarily complex mess won't run and it will cost a real fortune to fix! progress, no??