Scarab1988

Hello Corvette Forum.
Having just joined, I'd like to ask a few questions that you folks have probably had experience with.
I have a bone stock 1996 LT-1 C4 that runs well, but I want to plan an engine swap in the next year or so.
Are there any physical issues to putting in an LS motor? To keep it simple, I was thinking to put a stand alone Holley self programming fuel injection system on so I don't have to try to make 20+ year old systems work with new stuff?
It has a 4L60E I believe as the stock auto trans.
The other option I was considering is a first generation 350 and running aluminum heads and, again the Holley FI.
I used to build engines and race a series of '69 Camaros as a kid, but got out of it when life took over in the mid eighties, and I got into offshore power boat racing.
I'm really psyched to have gotten the bug back to start building cars again, but I've been out of it so long, everything has changed.
So please bear with me if I'm asking questions that are considered common knowledge these days.
Also, I'm a machinist, so machining and fabricating parts is not a big deal.
Thank you in advance for any tips, or ideas you can throw my way.
Merry Christmas

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Vetteman Jack

Moved to C4 Tech.

drcook

use this ===> c4 ls engine swap as a google search. lots of good information answering your question will pop up

biggiefl

Just put a procharger on it

Purple92

Just my $0.02 - but before you look at engine swaps - decide exactly what results you're looking for. Are you looking for 400 HP / 400 Torque ??? If so - you'll probably find that you can easily get that level out of a Gen I / Gen II SBC, and that integrating that into the C4 is significantly easier than getting an LS motor to co-exist with the C4 chassis & Instrumentation.

If you do some searching on this forum - you'll find people have swapped in Big Block Chevy motors - LS motors and even crazier stuff than that into C4's. But then read through the details - a lot of work went into those swaps. if you'll be happy with a 383 LT based motor with good heads and a solid rotating assembly - that will make 400+ HP and similar torque numbers - it will be a lot easier and cheaper to just do that.

Scarab1988

Thank you for responding .
450 HP / 400 ft. lbs torque would be perfect.
It would be cool to have an all aluminum LS 427, but in reality, I'd be very happy with the cast iron block / aluminum heads like I have now with the LT-1, but with a more traditional ignition system.
Thanks again for the advise.

Mike Holmen

I'm running a2005 LQ9 6.0L iron block/0317 heads. I'm around the 430HP t the crank. The swap is just like installing a SBC, pretty easy for just about anyone.

I bought a low miles engine for $1200, so you can do that. The newer engines work pretty awesome. Good fuel mileage and power.

It would be good to have someone else on this forum that has a LS engine in there C4. Its a way way better than the old motor.

RichS

Why not just build the LT1? It's a good motor and easy to make 400 hp. I did a LS swap for a buddy in a 85 and it wasn't too bad getting the a/c and gauges to all work, but in a 96 it may be a nightmare trying the get the dash, abs to work properly with the different computers.

Mr. Peabody

I also wanted to ask.... why not just just stroke the LT1? Put in a high stall TC and perhaps swap in a Dana 44?

aklim

Exactly. I am pushing 420 RWHP. I have everything working as it should be that is critical. Emissions seem to have fallen off the car. 383 stroker. Going to LS is a different issue.

Mike Holmen

Honestly if you have some money the GM LS3 crate engine, add a few parts. Probably the best bang for the buck. Here is an engine stock capable of 650HP at the crank and is reliable.

The LS3 is available brand new for low $6k area. This engine is probably close around the $10k mark and 650HP. and is brand new, all aluminum. A good 100-200lbs lighter than SBC.


LS engines are easier to work on. I'm using 700R transmission. I'm cheap so I have to recycle. I'm sure there is a 700-800HP available in the LQ9, just need some boost.

Scarab1988

Thank you for the additional feed back.
The reason I don't want to modify the original motor is, I want to pull out the original stock motor and trans, and put them into storage.
Some day I may want to put the original, numbers matching motor and trans back in the car.
Not that it's a super desirable collector car, but it may be some day.
I've got more research to do, but as an option, I've seen 383 cubic inch, 4 bolt main motors in Jeg's producing 450 hp+/- with similar torque numbers.
Even with the Holley EFI system, they are around $5,300.00 or so, and they offer a beefed up 4L60E for around $1,600.00.
Not sure what they would charge to buy out right without having cores, but that sounds like an affordable option.
Then again, it would be cool to have an LS3, all aluminum motor, with the option to get 650 reliable hp out of it, and be 150 to 200 lbs. lighter .
Taking that much weight out of the car helps with the power to weight ratio too .............
Decision's, decision's ......... Either option would be a blast to drive in a car that weighs a little over 3,000 lbs..
Merry Christmas

RichS

When I built my original 396, I bought a used 2 bolt f-body LT1 to rebuild. I have the original LT4 in the attic with all the other stock parts. I used the 2 bolt block and had billet splayed caps put on so its stronger. I think the torque of a stroker is more fun on the street. I have owned a bunch of LS Vettes and had blowers on them (one was 850 ish). They were all fast and fun cars but I love the GS with the stroker. I want to build a stroker short block for my ZR-1 eventually.

ddahlgren

Just go with a stroker LT1 and eliminate all the fabrication. Engine a tune and done.

mtwoolford

First question: Is the car registered in a state like California where it has to pass a visual inspection? If it is, then most of your other questions have already been answered.

drcook

You have a 96 LT1 just like I do. So remember you have the b*stard child of the tuning world. Not everyone has the interface necessary to deal with the '96 OBDII computer. Of course, going with an LSx based engine you will probably be swapping / interfacing a LSx engine compatible computer.

If you do not go the engine swap route, and simply go the engine build route, do some checking before hand as to who in your area (if any) can deal with the necessary changes that are going to ensue.

I see a Jet interface box in my immediate future due to the upcoming changes I am doing to my car.

Summit Racing has the LS3 crate engines, that for a person like me who is local to them, pushes the price to over $7000.00 because of the tax. While I understand that the GenII LT1/4 engines would play a game of chase that they cannot win in the end (due to the architecture of the LSx engines performance potential), even half of that would pep an engine up quite a bit.

With the '96 A4 cars you have to be realistic. A high HP engine is going to necessitate the 4L60E be reworked to handle the extra power and the Dana 36 is going to get broken if you are not responsible with the extra power or intend to race it, both turning that $7000.00 engine into a $10,000 car build as you can figure probably $1500.00 to buy the pieces to convert the rear to a Dana 44 and probably $2000.00 for the trans (based on a national known trans builder in my area saying my cost was $1500.00 plus parts to pull it, rebuild it and put it back in, cheaper if I pull and replace myself).

Tom400CFI

Ahhh, I think you're weights are WAY off. A "LS" weighs AROUND 450 lbs. Are you saying a Gen I engine in a later C4 weighs up to 650 lbs??

They don't. They weigh just about...450 lbs.

Read THIS, and note the specs for each engine "Vehicle weight".

Scarab1988

You asked where I am based. Southern New England, Cape Cod, MA.
I'm lucky an old friend from high school (class of '79 - Go Blue Knights !!! ) has been to all the GM schools over the last 40 years, but he has been working on mostly all stock vehicles, so hopefully he'll be able to figure out how to tune a mongrel.
I can machine the block, rods, crank and heads, but I don't know anything about the computers that run all the stuff when it gets into the car.
Time to crash course learn ....... Should be fun.
P. S. Driving responsibly ? Most of the time .........

aklim

I know that I can figure out how to change settings on any tune. What takes tons of experience is learning all the nuances of tuning on a dyno with sniffers, etc. This is something best left to a professional who has done it before or take your chances with some guessing.

Mike Holmen

My L98 had iron heads, yes I did take off 100-200lbs. An cast iron L98 iron engine are heavy, probably around the 600lbs area all dressed out. The accessories weigh a ton (steering, air pump, ac, even the water pump is cast iron). I removed all of the evap pollution, that vacuum air tank, iron exhaust manifolds. I'm sure I'm 200 lbs lighter with the swap.

My LQ9 is around 475lbs area all dressed out, give or take. An LS3 is even lighter with an aluminum block, around 400lbs.

I was quite surprised on how the original TPI350 weighed, probably weigh as much as a 5.9L Cummins.