time for a rebuild
Thread Starter
Intermediate
Joined: Jul 2014
Posts: 25
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From: lawrence NJ
time for a rebuild
90 c4 blew a head gasket. started taking it apart and decided to go with a rebuild on the engine. I would like to stay with the stock block, crank, rods, heads (if they are not cracked)and intake. I was thinking of going with 10-1 pistons and a decent cam.I am looking for info on a good combination that works well. Going to be on a budget ..... What cam should I go with that will not affect the computer ? Is there a cam and 'chip' that work well together ? Is 10-1 too much I know small blocks but not so much computer thanks 
Team Owner
Joined: Jul 2004
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From: Hartford WI
90 c4 blew a head gasket. started taking it apart and decided to go with a rebuild on the engine. I would like to stay with the stock block, crank, rods, heads (if they are not cracked)and intake. I was thinking of going with 10-1 pistons and a decent cam.I am looking for info on a good combination that works well. Going to be on a budget ..... What cam should I go with that will not affect the computer ? Is there a cam and 'chip' that work well together ? Is 10-1 too much I know small blocks but not so much computer thanks
If I rebuild on a budget, euphemism for cheap, I'd get a reman short block from maybe Jasper, hope for the best and be done with it. In fact, unless you have a reason to, perhaps it is better to stay stock, replace the head gasket and be done with it. IF the cam is worth power, you are going to have to tune or you won't get the max out of it or your money's worth. You also need intakes and headers and exhaust, then it's rear end time and trans time. Power will find the weakest link and break it. A great 383 will choke if the intakes and exhaust are not up to snuff. Even if you get a cam that is great, you will have to get a tune. Cheap tune is a "guesswork tune" where you tell them what you have and they guess what to write. More expensive is to datalog and tune, repeat till you get it perfect or dyno tune to get it perfect.
Thread Starter
Intermediate
Joined: Jul 2014
Posts: 25
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From: lawrence NJ
thanks Aklim,
I would like to know how much lift cam the stock heads take ? 480 ? I am looking at rebuild kits n such to get a good idea of whats what. A comp cam I am interested in advertises 480 int / 488 exh lift . Could the stock heads work with that without binding or spring problems ?
I would like to know how much lift cam the stock heads take ? 480 ? I am looking at rebuild kits n such to get a good idea of whats what. A comp cam I am interested in advertises 480 int / 488 exh lift . Could the stock heads work with that without binding or spring problems ?
Team Owner
Joined: Jul 2004
Posts: 28,422
Likes: 3,273
From: Hartford WI
thanks Aklim,
I would like to know how much lift cam the stock heads take ? 480 ? I am looking at rebuild kits n such to get a good idea of whats what. A comp cam I am interested in advertises 480 int / 488 exh lift . Could the stock heads work with that without binding or spring problems ?
I would like to know how much lift cam the stock heads take ? 480 ? I am looking at rebuild kits n such to get a good idea of whats what. A comp cam I am interested in advertises 480 int / 488 exh lift . Could the stock heads work with that without binding or spring problems ?
Thread Starter
Intermediate
Joined: Jul 2014
Posts: 25
Likes: 0
From: lawrence NJ
I agree - old valve springs , not going to end well.... i am trying to get a nice set up , and not run into a issue where I would need crazy machine work to the heads for Big springs. I heard a few people on this site liked the lt4 cam. Lobe separation and duration look pretty good.
Team Owner
Joined: Jul 2004
Posts: 28,422
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From: Hartford WI
I agree - old valve springs , not going to end well.... i am trying to get a nice set up , and not run into a issue where I would need crazy machine work to the heads for Big springs. I heard a few people on this site liked the lt4 cam. Lobe separation and duration look pretty good.
Last edited by aklim; Dec 18, 2015 at 08:03 PM.
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Racer
Joined: Oct 2014
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From: Apache Junction AZ
Hi rather b driving,
You are on the edge of a "slippery slope". You have gotten good advice so far. Either fix the head gasket (cheapest way out) or go all in. I can tell you from building engine experience, anything less than modifying the intake (port it or get larger or better), modifying the heads (porting or newer bigger breathing), headers that don't restrict (not necessarily perfectly tuned), and good cam and lifters (matched to the above with appropriate spring set up), you are going to get less than good expectations. I know this because I built a great engine once that exceeded my expectations so much for the money and time I put in it, that it galvanized my belief in "make it breath" philosophy. After all, the engine is just a giant air pump. My 396 with 425 heads, Z11 cam, Offenhauser tunnel ram, Hooker 2 inch headers and 4 inch collectors, and 2 AFB 4 barrels was a screamer and it was cheap. So you should start saving parts and match it all up rather than add one thing at a time. Disappointment is not worth the savings. When you get it right, you will only have this.
Good luck,
WEK.
You are on the edge of a "slippery slope". You have gotten good advice so far. Either fix the head gasket (cheapest way out) or go all in. I can tell you from building engine experience, anything less than modifying the intake (port it or get larger or better), modifying the heads (porting or newer bigger breathing), headers that don't restrict (not necessarily perfectly tuned), and good cam and lifters (matched to the above with appropriate spring set up), you are going to get less than good expectations. I know this because I built a great engine once that exceeded my expectations so much for the money and time I put in it, that it galvanized my belief in "make it breath" philosophy. After all, the engine is just a giant air pump. My 396 with 425 heads, Z11 cam, Offenhauser tunnel ram, Hooker 2 inch headers and 4 inch collectors, and 2 AFB 4 barrels was a screamer and it was cheap. So you should start saving parts and match it all up rather than add one thing at a time. Disappointment is not worth the savings. When you get it right, you will only have this.
Good luck,
WEK.
Race Director
Joined: Feb 2003
Posts: 16,475
Likes: 270
From: Kingman AZ
Cruise-In VII Veteran
Cruise-In VIII
St. Jude Donor '06-'07-'08-'09-'10-'11-'12-'13-'14-'15-'16
I spoke with a couple of engineers at Corvettes at Carlisle a few years back. They had a business that used a CNC machine to modify L98 intake systems for maximum airflow.
They had write-ups from several performance and Corvette magazines that showed their success.
They emphasized that the L98 Corvette engine is a system where everything must work together. With the proper cam, injectors, intake, exhaust, ignition, torque converter and rear end gears the car can put out some decent power. Just putting in a lumpy Comp Cam will not do much for you.
If you can't afford to do it right then don't do it at all.
I went home and added up the cost and could not afford the divorce that would ensue if I spent that much more money on a toy.
You would be farther ahead to sell what you have and buy a used C5 Z06.
The old adage still holds true, "Speed costs money. How fast can you afford to go".
Ever here of Dave Ramsey? His advice is to get out of debt. Work an extra job to obtain your dream and save up enough money to pay cash for what you desire. He likes to say that he gives the same advice that your grandmother would but he keeps his teeth in.
They had write-ups from several performance and Corvette magazines that showed their success.
They emphasized that the L98 Corvette engine is a system where everything must work together. With the proper cam, injectors, intake, exhaust, ignition, torque converter and rear end gears the car can put out some decent power. Just putting in a lumpy Comp Cam will not do much for you.
If you can't afford to do it right then don't do it at all.
I went home and added up the cost and could not afford the divorce that would ensue if I spent that much more money on a toy.
You would be farther ahead to sell what you have and buy a used C5 Z06.
The old adage still holds true, "Speed costs money. How fast can you afford to go".
Ever here of Dave Ramsey? His advice is to get out of debt. Work an extra job to obtain your dream and save up enough money to pay cash for what you desire. He likes to say that he gives the same advice that your grandmother would but he keeps his teeth in.
Last edited by corvetteronw; Dec 21, 2015 at 01:30 AM.
Race Director
Joined: Aug 2000
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- and my advice to the OP - I would personally repair the head gaskets, and be done with it! and this i totally agree -
You would be farther ahead to sell what you have and buy a used C5 Z06.
. the OP said "10:1 and a decent cam, but keeping the stock heads and intake," and i'm assuming the stock exhaust - 
. on top of the rebuild cost, he'll end up spending a lot of $$$ just to go a little, and I mean a LITTLE faster. ...and what are you going to do with all this "extra" horsepower - ??? - track the car? so, you knock off a few tenths - maybe? now what? spend the same, buy the Z - more fun, less aggravation -
Last edited by Joe C; Dec 21, 2015 at 03:00 AM.
Team Owner
Joined: Jul 2004
Posts: 28,422
Likes: 3,273
From: Hartford WI
They emphasized that the L98 Corvette engine is a system where everything must work together. With the proper cam, injectors, intake, exhaust, ignition, torque converter and rear end gears the car can put out some decent power.
Just putting in a lumpy Comp Cam will not do much for you.
If you can't afford to do it right then don't do it at all. I went home and added up the cost and could not afford the divorce that would ensue if I spent that much more money on a toy.
You would be farther ahead to sell what you have and buy a used C5 Z06.
The old adage still holds true, "Speed costs money. How fast can you afford to go".
He likes to say that he gives the same advice that your grandmother would but he keeps his teeth in.
Just putting in a lumpy Comp Cam will not do much for you.
If you can't afford to do it right then don't do it at all. I went home and added up the cost and could not afford the divorce that would ensue if I spent that much more money on a toy.
You would be farther ahead to sell what you have and buy a used C5 Z06.
The old adage still holds true, "Speed costs money. How fast can you afford to go".
He likes to say that he gives the same advice that your grandmother would but he keeps his teeth in.
The placebo effects are good though. Lol.
True. So is keeping the marriage intact still worthwhile? My buddy regretted it when he was crying in his beer after the divorce. Said if he knew then what he knows now, he'd have done his car. YMMV. LOL
IF you are not reall into speed, don't buy any Vette. Save the money for something worthwhile like Hooters and booze.
I like the one that says that it takes cubic dollars to go fast.
Yes but some grandmas are GILF. LOL
Team Owner
Joined: Jul 2004
Posts: 28,422
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From: Hartford WI
IMO, hot rodding a L98 on a budget - . the OP said "10:1 and a decent cam, but keeping the stock heads and intake," and i'm assuming the stock exhaust - . on top of the rebuild cost, he'll end up spending a lot of $$$ just to go a little, and I mean a LITTLE faster. ...and what are you going to do with all this "extra" horsepower - ??? - track the car? so, you knock off a few tenths - maybe? now what? spend the same, buy the Z - more fun, less aggravation -
. the OP said "10:1 and a decent cam, but keeping the stock heads and intake," and i'm assuming the stock exhaust - . on top of the rebuild cost, he'll end up spending a lot of $$$ just to go a little, and I mean a LITTLE faster. ...and what are you going to do with all this "extra" horsepower - ??? - track the car? so, you knock off a few tenths - maybe? now what? spend the same, buy the Z - more fun, less aggravation - 
Safety Car
Joined: Jan 2014
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From: Poughkeepsie New York
I agree with just replacing the gasket as long as everything else is fine. Theres no budget built with these motors/cars to make improvements. Every component on these motors is a restriction and choke point and it takes big bucks to replace each one. Headers alone are going to cost at least $600. Intake at least another $600. Heads? $1000. Engine parts? Dyno tune? Don't feel like everyone is against you, it's just the sad truth. And lots of us have been there. Can you do it on a budget? Sure, but it's going to take a while.
Team Owner
Joined: Jul 2004
Posts: 28,422
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From: Hartford WI
I agree with just replacing the gasket as long as everything else is fine. Theres no budget built with these motors/cars to make improvements. Every component on these motors is a restriction and choke point and it takes big bucks to replace each one. Headers alone are going to cost at least $600. Intake at least another $600. Heads? $1000. Engine parts? Dyno tune? Don't feel like everyone is against you, it's just the sad truth. And lots of us have been there. Can you do it on a budget? Sure, but it's going to take a while.
Race Director
Joined: Aug 2000
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I wish people would stop using the euphemism "budget" in this way when what they really mean is "cheap". He wants it decent but not affect the computer program or he'd have to spend more money to get it tuned properly. Doesn't want to protect stuff or replace it with better stuff. Speed costs cubic dollars. Start with 5 figures or forget the enterprise. Less than that and it will be unreliable or not gain much.
, 5-figures is some serious money, and i'll bet not within his budget, so he's better off spending the budget on replacing head gaskets and running those aluminum heads through a shop. the deeper he digs into this endeavor, the bigger budget he's going to need. I still stand by my statement - I would personally repair the head gaskets, and get a quality valve job, and be done with it! remember, it doesn't cost any more to go first class -- you just can't go as far!
Last edited by Joe C; Dec 21, 2015 at 03:46 PM.
Safety Car
Joined: Jan 2014
Posts: 4,017
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From: Poughkeepsie New York
Team Owner
Joined: Jul 2004
Posts: 28,422
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From: Hartford WI
well first of all, I DIDN'T mean cheap, I DID mean BUDGET.
second, does he really need a rebuild? probably not, but he's going to spend a large part of this BUDGET for what - ??? - and that "for what" is a lot of work.
third, what kind of budget are we talking about? 10:1 and a decent cam with remaining stock components to me is a waste of the BUDGET.
5-figures -, 5-figures is some serious money, and i'll bet not within his budget, so he's better off spending the budget on replacing head gaskets and running those aluminum heads through a shop. the deeper he digs into this endeavor, the bigger budget he's going to need.
I still stand by my statement - I would personally repair the head gaskets, and get a quality valve job, and be done with it! remember, it doesn't cost any more to go first class -- you just can't go as far!
second, does he really need a rebuild? probably not, but he's going to spend a large part of this BUDGET for what - ??? - and that "for what" is a lot of work.
third, what kind of budget are we talking about? 10:1 and a decent cam with remaining stock components to me is a waste of the BUDGET.
5-figures -
, 5-figures is some serious money, and i'll bet not within his budget, so he's better off spending the budget on replacing head gaskets and running those aluminum heads through a shop. the deeper he digs into this endeavor, the bigger budget he's going to need. I still stand by my statement - I would personally repair the head gaskets, and get a quality valve job, and be done with it! remember, it doesn't cost any more to go first class -- you just can't go as far!
Not sure if he needs a rebuild until we see a leak down test at least. I'd freshen the heads if they are off since they are old and a broken spring would demand a rebuild if the piston hits the valve.
I agree. Either be prepared to put real money down or replace the gasket.
Doesn't sound like he is BOTH able and willing to pay so I would not even venture down that road. Hookers and blow is a better investment.
Actually quite often it is cheaper in the long run to go first class when 2nd comes to bite the *** at a later date
Team Owner
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From: Hartford WI
Melting Slicks
Joined: Jan 2009
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From: folsom california
On a budget?
Reuse your crank.
If you want 10:1 compression you'll need new pistons. Most piston sets come with rings. Have the block bored / honed as appropriate.
You can reuse the rods but if you intend on having them resized / rebuilt you'll soon come to the conclusion that new rods are an inexpensive alternative.
Take everything, damper, crank, rods, rod bearings, pistons, rings, flywheel / flex plate in and have it balanced as an unit. The result will be a very nice rotating assembly that won't break the bank.
Personally from your posts, I'd forget about the lower engine, unless of course you find excessive wear or damage to the cylinder wall. Pull the heads, have the heads rebuilt, get new head gaskets, and reassemble the engine. Then drive it until it starts to show excessive oil consumption or blow by past the rings, which could be another 100,000 miles down the road.
Take a good look at the cam and lifters, they don't last forever and if either show any sign of wear, replace them.
Reuse your crank.
If you want 10:1 compression you'll need new pistons. Most piston sets come with rings. Have the block bored / honed as appropriate.
You can reuse the rods but if you intend on having them resized / rebuilt you'll soon come to the conclusion that new rods are an inexpensive alternative.
Take everything, damper, crank, rods, rod bearings, pistons, rings, flywheel / flex plate in and have it balanced as an unit. The result will be a very nice rotating assembly that won't break the bank.
Personally from your posts, I'd forget about the lower engine, unless of course you find excessive wear or damage to the cylinder wall. Pull the heads, have the heads rebuilt, get new head gaskets, and reassemble the engine. Then drive it until it starts to show excessive oil consumption or blow by past the rings, which could be another 100,000 miles down the road.
Take a good look at the cam and lifters, they don't last forever and if either show any sign of wear, replace them.
Last edited by mtwoolford; Dec 21, 2015 at 11:30 PM.