DirtyDiesel New Reader
March 11, 2015 12:32 p.m.

My dream has been to swap in a duramax or powerstroke into a cheap C4 vette. The problem has always been what manual trans gearing would work. I know both the trucks came with a 6 speed manual but not sure if the mounting would work in the vette. Would the T-56 work with a super low rear end? I think I've read some of them came with a 3:07 rear diff?

Help me make my dream come true!

81cpcamaro HalfDork
March 11, 2015 12:40 p.m.

Info on the web says the T56 won't hold up to a Duramax, just too much torque. Not many good choices in manual trans for this. Besides that, will the Duramax even fit in a Corvette? Watching Trucks on powernation, where they are trying to put one in a 87 C10, they will have to run a pretty big cowl hood to clear the engine. Can't imagine trying to shoe horn it into a vette.

Type Q Dork
March 11, 2015 1:01 p.m.

Anything can be made to fit with enough time and money.

drdisque Reader
March 11, 2015 1:14 p.m.

I'd imagine that the engine is far too tall, especially when you consider the oil pan and the fact that it probably needs a big honking oil pan.

Truck smallblocks won't even fit into corvettes unless you swap out the oil pan.

Trackmouse Reader
March 11, 2015 1:25 p.m.

Diesel I-6? Or turbo D four banger?

NGTD SuperDork
March 11, 2015 1:28 p.m.

I think you should compare the overall height of the Duramax to the TBI 350.

You might have to run a cowl hood that would put a Pro Stock drag car to shame!

Cotton UltraDork
March 11, 2015 1:33 p.m.

You could probably put a 6.2 diesel in it without too much trouble, but they're not very powerful. I have an extra 6.2 and tried to get my friend to swap it into his beater C4, but he wouldn't do it.

mike New Reader
March 11, 2015 1:40 p.m.

Guy in British Columbia did something interesting ...

http://www.corvetteonline.com/news/video-46-mpg-turbodiesel-c3-corvette/

turboswede MegaDork
March 11, 2015 1:45 p.m.

I'm sure if you used one of the old BOP diesel V8's with the right combo of parts you could make it work. You'd have a slow, failure prone POS of a Corvette, but it should fit the easiest out of the various options available.

Otherwise the corvette being fibgerglass would likely need a hood scoop added to fit the taller engines that are prevalent these days.

I think a BMW or Jag V12 would make more sense for a swap (which is basically no sense, much like the idea of a disel 'vette), but this is just a personal opinion.

Kenny_McCormic PowerDork
March 11, 2015 1:58 p.m.

Gear ratios are the least of your concerns.

Anything is possible with enough fab work, and you'll be doing a lot of that to make this work. The stock diff will be marginal at best, assuming you get a car with the Dana 44. A C4 doesn't have a trans cross member, or provisions for one, the stock trans is mounted to a piece of C channel that runs to the rear diff. You'll probably need to open up the trans tunnel to fit a 1 ton truck trans strong enough to take the torque. The front suspension probably wont like the extra weight. You'll probably need to make an oil pan to get the engine reasonably low. And as mentioned, a lot of creativity will be needed to get the hood back on it, if it's even possible without a huge cowl induction bump.

It can probably be done, but it will be far from a bolt together stuff from the GM parts bin type affair.

oldopelguy SuperDork
March 11, 2015 2:38 p.m.

The 3.x L Isuzu turbo diesel from the Trooper/Bighorn would be a relatively easy fit and you could crank up the boost to make it interesting. There is usually a couple on evilbay.

March 11, 2015 5:17 p.m.

I think it's a cool idea to do. You can also cut the hood to make the engine fit, especially if you didn't daily it. You can have a T56 built to hold up to that much torque, but you may need a custom bellhousing.

chiodos Reader
March 11, 2015 5:40 p.m.

Heres some brain fodder. Was going to suggest a 4bt but its not as light as I thought. Its going to be a heavy sob either way. http://www.dieselhub.com/tech/engine-dimensions.html

Sonic SuperDork
March 11, 2015 7:15 p.m.

My friend made one for Lemons, using an Oldsmobile 350 and TH400. He ran it on veggie oil, hence the name of "Corvegge"

Here's an article: http://www.autoblog.com/2012/11/03/cor-vegge-puts-veggie-oil-to-the-corvette-test-at-lemons/

In short, it was awful. The motor couldn't keep head gaskets in it, despite ARP studs and cometic gaskets, and pulling the heads was an engine out job. When it ran, it was incredible from 0-6 (yes, six) MPH, and then it was awful. Epically slow as expected, and more than last throttle just made it louder, but not any faster. Great idea in concept and it was pretty well executed, but the Olds 350 is just E36 M3.

Junkyard_Dog SuperDork
March 11, 2015 8:05 p.m.

How much HP/TQ does an 85 TPI Vette make? How about a late model VW TDI?

Only thing I can think of that is small, readily available, and would probably fit.

chiodos Reader
March 11, 2015 8:24 p.m.
Junkyard_Dog wrote: How much HP/TQ does an 85 TPI Vette make? How about a late model VW TDI? Only thing I can think of that is small, readily available, and would probably fit.

84 was 205 and 290 tbi where the 85 was 230 and 330. Late model tdi was 130-150hp and 230-250 torque iirc... not to mention those tdi motors are more pricey than an ls1 and t56

Streetwiseguy PowerDork
March 11, 2015 9:28 p.m.

You can barely fit a Chev 350 in a 4th gen Corvette. Never in my life have I encountered a car that lies so badly about how easy the engine is to work on.

At first glance...then berkeleyberkeleyberkeley.

chiodos Reader
March 11, 2015 9:41 p.m.
Streetwiseguy wrote: You can barely fit a Chev 350 in a 4th gen Corvette. Never in my life have I encountered a car that lies so badly about how easy the engine is to work on. At first glance...then berkeleyberkeleyberkeley.

I love how any literature you find on a c4 all state how "its a mechanics dream to work on because of the clamshell bonnet"

novaderrik UltimaDork
March 12, 2015 5:09 a.m.
81cpcamaro wrote: Info on the web says the T56 won't hold up to a Duramax, just too much torque. Not many good choices in manual trans for this. Besides that, will the Duramax even fit in a Corvette? Watching Trucks on powernation, where they are trying to put one in a 87 C10, they will have to run a pretty big cowl hood to clear the engine. Can't imagine trying to shoe horn it into a vette.

he got that engine to fit by trimming some of the bracing under the hood, but decided to put the cowl hood on it just because they probably had a sponsor willing to give them one... but an 80's C10 probably has about a foot more hood clearance than a C4 Vette, so, yeah, you'd be looking at either the most ridiculous cowl scoop ever, a big hole cut in the hood, or no hood at all..

and that's not even taking into consideration the extra 500 pounds on the nose just from the engine alone..

Vigo PowerDork
March 12, 2015 7:06 p.m.

I've done a decent amount of work to a c4 and it's honestly not as bad as it looks for common repairs.

I've driven a lot of c3s and c4s and honestly i'm a pretty strong believer that what they need is smaller engines that perform a lot better. To me that would make them much better cars. If i ever get a c3 it is probably getting a turbo 4cyl swapped in.

JFX001 UberDork
March 12, 2015 9:02 p.m.

In reply to Vigo:

I wouldn't mind seeing the new Camaro 3.6 in a C4. 323hp / 278 ft-lbs with the 6 speed.

March 12, 2015 10:02 p.m.

I once thought of doing a ToC with a Ford Windsor powered C4 Vette, just for the sacrilege factor. Let me ask this: Is the point of this exercise to have a good diesel Vette or to have a spectacular or perhaps absurd diesel Vette? Or, more appropriately, is the point to have a good Vette that isn't propelled by a SBC, or just have a diesel engine in a Vette?

Have you considered an Isuzu diesel engine, for instance the 4 cyl common in the NPR cabover box trucks? I think they bolt up to GM automatics. You may find the packaging a little easier than a 4BT Cummins or similar.

If spectacular / absurd is your goal, consider a 53-series Detroit Diesel. It would require an absurd amount of butchery, but the noise is glorious!

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