Rebuilding engine...restore orginal horsepower?
Thread Starter
Heel & Toe
Joined: Jun 2002
Posts: 17
Likes: 0
From: Humble TX
Rebuilding engine...restore orginal horsepower?
I am thinking about getting my engine rebuilt on my 1988 Corvette. My car orginally came with 245 Horsepower out of the factory when new. Right now nothing is wrong with my engine but, I dont believe that my car's Horsepower is where it needs to be. I have not taken the car to get it dyno yet but, I dont want to loose time or money finding out something I already know. My question is... will rebuilding my longblock engine restore my car back to 245 hp? If anyone has had their Corvette engine rebuilt before or can give me a knowledgeable opinion on what the outcome will be please let me know. Thanks :seeya
Team Owner
Joined: Apr 2001
Posts: 22,267
Likes: 3
From: Dallas TX
Re: Rebuilding engine...restore orginal horsepower? (elite)
ANY rebuild on a corvette should restore you to at least 50hp over stock ;) :D If not, ya didn't "rebuild" it right.. hehe :jester
[Modified by GlockLT4, 12:55 AM 10/9/2002]
[Modified by GlockLT4, 12:55 AM 10/9/2002]
Racer
Joined: Feb 2002
Posts: 424
Likes: 0
From: Anaheim Ca
Re: Rebuilding engine...restore orginal horsepower? (GlockLT4)
If you're rebuilding it, than you'll be boring out the cylinders which will give you more cubic inches, depending on what amount you bore it out. That's how the 383's are created. That will give you more horsepower. If you're "overhauling" it, then you're not changing the cubic inch displacement, but even with an overhaul, you'll have tighter piston rings, sealing the pressure in the cylinder more efficiently, which will also raise your horsepower, but not as well as rebuilding the engine. Depending on how much money you want to spend, you can really "trick" the engine out when rebuilding it. Another thing to keep in mind is what your state's smog control rules consist of. In California, for example, if you put in a hotter cam, that can cause you to fail the test. If you're in a State with less restritve rules, you can add alot of goodies to bring the horsepower up beyond the factory ratings.
Team Owner
Joined: Dec 2000
Posts: 90,675
Likes: 304
From: SE NY
Cruise-In II Veteran
Re: Rebuilding engine...restore orginal horsepower? (elite)
I would bet your engine is down about 10hp or so from average new.
There's a much simpler way to improve HP.
-remove the "frisbee" from the water pump pulley=10hp
-replace dist cap/rotor, wires and plugs (cut back ground electrodes=10hp)
-install a K&N air filter with cut lid=10hp
For about $200 you will have a more responsive & powerful engine than new (by about 20hp) and it will still be quiet and smooth.
If you get a chance get some dyno pulls before and after the above mods. If it's an A4 divide the RWHP by .83 to get crank HP.
There's a much simpler way to improve HP.
-remove the "frisbee" from the water pump pulley=10hp
-replace dist cap/rotor, wires and plugs (cut back ground electrodes=10hp)
-install a K&N air filter with cut lid=10hp
For about $200 you will have a more responsive & powerful engine than new (by about 20hp) and it will still be quiet and smooth.
If you get a chance get some dyno pulls before and after the above mods. If it's an A4 divide the RWHP by .83 to get crank HP.
Race Director
Joined: May 2001
Posts: 14,165
Likes: 9
Re: Rebuilding engine...restore orginal horsepower? (elite)
One thing to keep in mind, if you dyno and it doesn't make 245 don't be pissed. The rated hp when it came from the factory would have been measured at the flywheel, therefore ignoring all drivetrain losses. If you dyno it and it make around 200-220 you're just fine.
If the car has been run very hard and it doesn't make good compression anymore it could be making less horsepower than it was. If it's in good tune and has good compression and just feels a little more sluggish than it used to maybe it's just that your valve springs are getting weak. I'm willing to bet that the motor is plenty healthy, you need to replace the restrictive TPI intake with a super ram and put in a small cam. With these two things you won't really have to get too far into the engine and you'll make lots more horsepower than stock.
BTW, how many miles are on it?
If the car has been run very hard and it doesn't make good compression anymore it could be making less horsepower than it was. If it's in good tune and has good compression and just feels a little more sluggish than it used to maybe it's just that your valve springs are getting weak. I'm willing to bet that the motor is plenty healthy, you need to replace the restrictive TPI intake with a super ram and put in a small cam. With these two things you won't really have to get too far into the engine and you'll make lots more horsepower than stock.
BTW, how many miles are on it?
Drifting
Joined: Feb 2000
Posts: 1,994
Likes: 0
From: Charleston, WV
Re: Rebuilding engine...restore orginal horsepower? (Nathan Plemons)
Before you go pulling that engine: check the compression and leakdown. Get a GOOD oil pressure reading ......(not with the stock guage). I'm guilty of telling people that if it ain't broke don't fix it. If you want more hp than stock then soup it up but don't just tear it down for the hell of it. I have 180K on mine and it runs REAL strong ............ (knocking wood here) ...... :seeya
Safety Car
Joined: Jul 2001
Posts: 4,524
Likes: 0
From: Sacramento CA
Re: Rebuilding engine...restore orginal horsepower? (Netnarc2)
whats your state's smog control rules consist of. In California, for example, if you put in a hotter cam, that can cause you to fail the test. If you're in a State with less restritve rules, you can add alot of goodies to bring the horsepower up beyond the factory ratings.
It's faster but not as fast as I thought it would be. More top end little less low end.
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer
Brett Foote
10 Things Every Corvette Owner Needs (2026 Edition)
Michael S. Palmer
8 Most "Only Corvette Owners Understand" Quirks and Problems
Pouria Savadkouei
10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years
Joe Kucinski
How Much Horsepower Every Corvette Engine "LOST" in 1972
Joe Kucinski
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!
Michael S. Palmer
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!
Joe Kucinski
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter
Joe Kucinski
8 Coolest Corvette Pace Cars (and Replicas) of All Time
Verdad Gallardo
Thread Starter
Heel & Toe
Joined: Jun 2002
Posts: 17
Likes: 0
From: Humble TX
Re: Rebuilding engine...restore orginal horsepower? (Nathan Plemons)
How much does the super ram and small cam cost? Where can I buy these parts at a cheap or reasonable price? Can I install it myself and if so how long does it usually take?
