C4 Tech/Performance L98 Corvette and LT1 Corvette Technical Info, Internal Engine, External Engine

L98 engine advice

Old 12-27-2010, 09:59 PM
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Sober1
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Default L98 engine advice

Hello corvette land. My 1st post here.
Recently purchased an 88 corvette with a bad rod bearing. Pan and rod caps came in a box with the car.

I already have borrowed an engine hoist and am ready to remove the engine soon.

Local engine/balance shop has quoted me 2500 for a newly machined and balance long block. 3500 would be my outside budget for the mechanical portion of the project. I am aware that making power costs money.

Problem: 240 rated hp in a rebuilt corvette motor seems so under-rated. I am almost finished with an overhaul of a comperable (non-smog) motor of aprox. cid w/ an output in the 430 hp range.

What can be done within my budget to make this corvette run proudly. Remember my budget is capped for now around 3500. So I am not expecting a mid to low 11 second car. Very low 13's or maybe better is more realistic imo.

This car has to pass smog as I live in central CA.

I am being advised by a local corvette guru to leave it stock. He is telling me it will never run correctly if its modified and that those with fast corvettes like mine are only driving 1/4 mile at a time.

Please advise....I am all ears.

Thank you in advance for any tech support.
Old 12-27-2010, 10:09 PM
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tehcarguy
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Listen to Pete, he knows a very lot about these engines(I'm glad you changed your picture, Pete, that other one was starting to scare me.). Rebuild the engine yourself, it will be extremely cheaper. If it were me, the very first thing I would do is buy better heads and a cam, along with other valvetrain parts.
Old 12-27-2010, 11:09 PM
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John A. Marker
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How many miles on the current engine? These engines are known for hitting the 200,000 mile mark if they are taken care of by their owners.

If there are not too many miles, you might consider just pulling the crank and have it turned and go with new bearings. Then a cam like the Lingenfelter 74211 (passes SMOG) a good set of heads and you can be in the mid to low 13's. If you do most of the work yourself except machine work, you can keep the costs down.
Old 12-27-2010, 11:34 PM
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earthquake68
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I like the way Pete said it. Your engine builder's advice was well intentioned, if not completely inaccurate. My engine has injector and intake work. It's also been swapped to a roller cam set up. I drove 1200 miles straight through from Florida to Missouri without issue. Slightly longer than the afore-mentioned 1/4 mile. $3,500 will buy a complete crate engine from Summit. I would shop around or do some research and build it yourself.
Old 12-28-2010, 02:07 AM
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Sober1
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Thanks to all those who responded. I am doing alot of research. Bottom line looks like my build will more resemble a stock or lightly modified build at best.
I would like to benefit from a tried and proven design that is within my budget. I am capable of building the internals of this engine myself. This could free up a few dollars for a better intake set up and or exhaust.
BTW..what specific intake parts are needed to let these motors breath well and still pass smog? I am new to this efi / smog compliant hp improvements.
I would like more cam options that are for sure smog freindly if possible.
I will research the cam spec for the Lingenfelter 74211

Thanks again...all info shared is greatly appreciated.
Old 12-28-2010, 08:58 AM
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CorvetteMike2024
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240 hp does sound wimpy. But look at the torque numbers. L98's have gobs of torque. I have an L98 and it suits my needs.

Every year the Ca. govt. is dropping the max. allowable limits on smog testing to get these old cars off the road. Once you have it running in stock form you may like it.

Last edited by CorvetteMike2024; 12-28-2010 at 09:00 AM.
Old 12-28-2010, 09:29 AM
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ddahlgren
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Every year the Ca. govt. is dropping the max. allowable limits on smog testing to get these old cars off the road. Once you have it running in stock form you may like it.
This ought to be illegal as they are asking the owner to do better than the factory engineers could and the cars were all sold to legally operate on the CA roads when new. They are basically confiscating your property by changing the rules of the game. I wonder how someone like Jay Leno can run all his old cars on the road? Possibly different rules?? sigh. Is there any point in time in CA that a car becomes exempt from smog?
Old 12-28-2010, 09:37 AM
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Originally Posted by ddahlgren
This ought to be illegal as they are asking the owner to do better than the factory engineers could and the cars were all sold to legally operate on the CA roads when new. They are basically confiscating your property by changing the rules of the game. I wonder how someone like Jay Leno can run all his old cars on the road? Possibly different rules?? sigh. Is there any point in time in CA that a car becomes exempt from smog?
We test back to 1976. Seems to me most of Jay's cars are either pre smog or new.

There was alot of good info regarding ca. lowering limits in my failed smog thread.

Mike
Old 12-29-2010, 12:45 AM
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Calderone
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But ...are you keeping the car ? if you are , you can always swap cam,heads,intake in th future , now that the engine is out and removed i woulnd't make the mistake i made.
I would stroke it to 383, i have no idea how much more is involved but if you can
get forged pistons and rods,plus the stroker crank.
Im not sure if this will fit the budget but back in 2008 i rebuilt my engine on a budget (ZZ4 Cam and springs) and that was all, 3 years later i wish i had a 383.
Old 12-29-2010, 01:15 AM
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87 vette 81 big girl
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Originally Posted by Calderone


But ...are you keeping the car ? if you are , you can always swap cam,heads,intake in th future , now that the engine is out and removed i woulnd't make the mistake i made.
I would stroke it to 383, i have no idea how much more is involved but if you can
get forged pistons and rods,plus the stroker crank.
Im not sure if this will fit the budget but back in 2008 i rebuilt my engine on a budget (ZZ4 Cam and springs) and that was all, 3 years later i wish i had a 383.
383's are real terrors on the street.

Especially if built right and a 150 HP + shot of nitrous oxide is used at launch and you can get the power to the ground on launch.

A friend of mine had a 1987 Chevy Monte Carlo. Built up a 383 with old 292 casting double hump heads. Sprayed nitrous into it.
Used a 700 R4 trans. Installed a 12 bolt rear from 1970 Chevelle with 4.10 gears. Ran Mickey Thompson Tires out back.

Upon launch even on street, he would lift the front wheels off the ground easily 6 inches, sometimes 2 feet. LOL

And was gone in a hurry..........

In my 1970 Pontiac Ram Air 4 Trans Am 4- speed ( No Nitrous), He would get me out of the hole - launch.

I would catch up at the end of 3rd gear(ready to make my 7,000RPM shift),

At the 3- 4 shift in my car, I would over take him around 100 MPH.

If I screwed up shifting ever, he would be gone. LOL

That 383 was fast lol.

He quite never got over getting beat by me in my T/A.

As he never got beat.

He would show up nearly every night wanting to race wherever I was locally.

Or launch his car in front of myself or others wherever we were.
Old 12-29-2010, 06:11 AM
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Originally Posted by 87 vette 81 big girl
383's are real terrors on the street.

Especially if built right and a 150 HP + shot of nitrous oxide is used at launch and you can get the power to the ground on launch.

A friend of mine had a 1987 Chevy Monte Carlo. Built up a 383 with old 292 casting double hump heads. Sprayed nitrous into it.
Used a 700 R4 trans. Installed a 12 bolt rear from 1970 Chevelle with 4.10 gears. Ran Mickey Thompson Tires out back.

Upon launch even on street, he would lift the front wheels off the ground easily 6 inches, sometimes 2 feet. LOL

And was gone in a hurry..........

In my 1970 Pontiac Ram Air 4 Trans Am 4- speed ( No Nitrous), He would get me out of the hole - launch.

I would catch up at the end of 3rd gear(ready to make my 7,000RPM shift),

At the 3- 4 shift in my car, I would over take him around 100 MPH.

If I screwed up shifting ever, he would be gone. LOL

That 383 was fast lol.

He quite never got over getting beat by me in my T/A.

As he never got beat.

He would show up nearly every night wanting to race wherever I was locally.

Or launch his car in front of myself or others wherever we were.
This is the best choice. The 240HP will not make you happy for long, there are guys out there that hunts for corvettes to beat up on them.

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