Rebuild or Swap?

[Abarrios]

Hey guys, I have a 1985 corvette with the stock L98. Its been giving me some trouble lately (burning oil, stalling) and I am not sure if I should rebuild it or just swap it in general. The guy I bought it from did not take very good care of it and it's really starting to show. I've tried to keep it healthy as possible with it ripping it out but I think it might be time. What do you guys think?



Let me know if you need any more info.

Thanks, Andrew

[71maroesteban]

What's the budget? And what do you plan on swapping in rebuilding that motor shouldn't cost anything

[Abarrios]

I have about a three thousand dollar budget, and if I were to swap I would try to find an ls1 or a sbc 400 for a carb conversion. For rebuilding I would do basically everything. (Intake,heads,pistons,plumbing, TB, all gaskets and seals, rockers, most if not all bearings, oil and water pump,freeze plugs,belts and chains)

[WallaceMFG]

Depends on the budget. You could make a pretty good engine with what you have, and you'd be able to keep all the accessories, clutch, TPI, etc... Otherwise I'm sure you can buy all the pieces for an LSx swap

[andrewb70]

Since the car is already set up for EFI, I would do a LSx swap. Even a 5.3L engine will make way more power than a L98 and will probably get you 23 mpg.

Andrew

[Abarrios]

So it sounds like doing an lsx swap is more practical. Not only for better performance but also more practical for a daily driver.

[71maroesteban]

I don't see a lsx swap happening for 3k engine would be around 1k the to get accessories that will work another 1k also you'd need to swap the intake and rework the harness and get a tune and after all that you'd be using a used motor instead of rebuilding yours and having a almost new motor

[CampbellshotrodsAZ]

I would definitely hold off to do an LS swap until you have like $4 or 5k to play with. You can rebuild the L98 but in the end... you'll have a rebuilt 1985 era L98. Good engine, no doubting that, but nothing exhilarating by today's standards, and is expected. You are also severely limited in building the engine up as well, you've have to spend a fortune to get it to keep up with the same car with an LS.

On that topic... an LS powered C4 sounds like a blast! These engines have near endless potential, and just a good intake, cam, and headers will get you high 300 rwhp super easily.

[Abarrios]

Alright so I'll start ripping apart the l98 here pretty soon. Any suggestions for upgrades? Besides cam,heads,and intake?

[WallaceMFG]

I'd probably do an exhaust and a new tune to take advantage of the gains from updating the top end of the motor, and bigger injectors if the stock ones can't flow enough. If you'll ever autocross the car, oil pan with baffles. Whatever you do with the heads, get studs put in them so you can use roller rockers. Polish the lifter valley to help oil flow back to the sump quicker. Lots of little things can help make power and make the engine more durable.

[Abarrios]

Thanks for all the help guys! I'll post with the results soon!

[AMSOILGUY]

What lubricates are you using to break it in?

[reedld]

LT1? Kinda the forgotten engine...great power..drops right in.. Accessories work...often can be found cheap!

[MonzaRacer]

If I had option to rebuild look around for 86 1/2 and up roller block, one piece rear main engine.
IF you have L98 aluminum heads (also set on Ebay)you If you will beat on it spring ofr forged pistons so its more suitable for boost or spray later on. cost vs hyperutectics and Forged is negligible. Invest in good one piece SFI fly wheel and balancer.
I assume its TPI so locate a good set of matched and cleaned injectors at minimum, up grade the fuel rail by removing the flow restrictor/baffles from the rails and add in an adjustable, boost reference regulator ( price is negligible between one or another ) IF you can swing it look at Injector Dynamics injectors as they have better spray resolution and can handle higher pressures and such for the price.
with a roller block look at the LT4 HOT cam, you wont need the 1.6 roller rockers if you dont want too but can add them later on. Solid, healthy torque producing cam.
Z-springs are plenty with the HOT cam, just make sure your heights are properly set.
Also roller rockers can be done now or later but at least an accurate set of new ones are in order.
Simple efficient set of headers, preferably stainless if you can find good price.
coating your exhaust with thermal barrier internally helps considerably and for reasonable cost if done at home.
Another trick is flush whole cooling system, new pump, hoses, etc. Look at Evanscooling.com. Look at a decent all aluminum rad and Evans NPG+ then you have zero issues in cooling and you can run engine hotter and never boil over as it has 375 degree boiling point!
And it never freezes solid just slushes up when subjected to freezing temps.
Plan your work, and work your plan. I have two cars on drawing board and NOW since talking to a lady opened up possibility of needing one running for Car cruise in September, and neither is even remotely ready to drive! ooppss , pretty ladies just seem too make us trip over our selves.
So IF things work out I MIGHT try to get one of the cars running by Sept, Lord help me get the gumption up to get too work.
Last time I built a car i did it in a week, pulled one apart and installed everything in a similar car. also swapped engine in my truck out in less than week few year after.
Bad thing, no garage, or shade tree, or nothing.
Good Luck
Lee

[NJSPEEDER]

With your budget, if you aren't going for an all out race car, I would suggest just grabbing a crate motor and throwing it in with the L98 EFI set up. The computers can be tuned and a lot of shops still do the chips for them. If not converting to MegaSquirt or similar isn't expensive, someone may even have a direct swap harness already available.

Whatever you do the one thing I think you need to keep in mind is that the previous owner didn't take great care of the car. If you spend a lot of money putting in monster power what are you going to be buying next? Trans? Rear? Fixing a floor pan and buying a drive shaft?

-Tim