L98 engine rebuild
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From: Lakewood Ranch Florida
L98 engine rebuild
I have a 1991 vert with the L98 engine pushing 150K miles. Car is in perfect shape outside and good interior so I'm looking at a project to beef it up a little and have it be reliable stree show fun car. My question is should I just rebuilt back to stock (rest of car has mild mods do not NCRS car!). Or should I punch it out to 383 and put a carb on it?? Might be eaiser for rookie to tune without fuel injection. Am I right? Advice please, anyone done this and has experience please let me know.
Melting Slicks
Joined: Dec 2008
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From: Mystic CT
It is all about budget in the end. Personally if I did not want a bunch of issues and time invested would drop in a GM 383 crate long block with a First intake. It ill make a ton of torque 0 to 60 stuff will be very impressive etc. still make plenty of power on top compared to a stockL 98. Some sort of upgraded exhaust is in order but be carefulon the mufflers etc as loud can get old quickly. I have a Borla cat back on my stock 91 and really starting to hate it as 100 mile drive can get very tiring. The only problem with the GM 383 is you have to be careful with the headers as they have raised ports and Hooker at least and assume others make the ports on center to the bolt pattern.
Dave
Dave
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From: Lakewood Ranch Florida
Can't I just punch out the stock L98 block at a machine shop to 383?? On the cheap? Don't want to spend a ton maybe 2-3 grand at most. My block is good just having some fuel electronic issues at times so want to make it more reliable and thought I could just use what I have and have a shop punch it out and get rid of sketchy computer by going with carbed motor. Am I wrong or hoping this could be fairly easy to do? Have straight 3" straight pipes with flow masters too so loud!! I do love this car 1st vette I ever bought do I'm keeping it just want to do some kind of motor rebuild. Want it to run like a champ!!
Heel & Toe
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Can't I just punch out the stock L98 block at a machine shop to 383?? On the cheap? Don't want to spend a ton maybe 2-3 grand at most. My block is good just having some fuel electronic issues at times so want to make it more reliable and thought I could just use what I have and have a shop punch it out and get rid of sketchy computer by going with carbed motor. Am I wrong or hoping this could be fairly easy to do? Have straight 3" straight pipes with flow masters too so loud!! I do love this car 1st vette I ever bought do I'm keeping it just want to do some kind of motor rebuild. Want it to run like a champ!!
What do you want out of this build? If you're wanting to mostly reuse components and just bump the cubic inches while you're there, then yes it can be done low cost & straight forward. BUT what are your fuel injection problems? There's no sense doing anything until you get that squared away. Also there's tons of info to help select a mild replacement cam and budget valvetrain if you go the rebuilt/stroked route.
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From: Lakewood Ranch Florida
Just looking to freshen up the motor. Has a lot of miles and have had some electrical issues. I've been thru 3 alternators! Currently only issue is when the is a quarter tank of gas or less when you make a 90 degree turn from a light for instance it sputters like it's not getting enough fuel. But goal of project is to have a nice reliable motor with maybe some additional power for not a lot of cash. And learn about rebuilding motors for fun. So basically a fun project to do that I can get my hands dirty in! I've never rebuilt a motor before so it will be fun hopefully. And I love that corvette, it's the first one I ever purchased!
Race Director
Joined: Jun 1999
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From: Merritt Ils Fl
Any time you begin to wander very far off the path The General laid out for the SBC you begin to forfeit reliability and economy while adding expense. A rebuild to near stock will give you more that enough power to keep a grin on your face. Unless you are a serious racer it don't get any better than that.
Team Owner
Joined: Jul 2004
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From: Hartford WI
My question is should I just rebuilt back to stock (rest of car has mild mods do not NCRS car!).
Or should I punch it out to 383 and put a carb on it?? Might be eaiser for rookie to tune without fuel injection. Am I right?
Advice please, anyone done this and has experience please let me know.
Or should I punch it out to 383 and put a carb on it?? Might be eaiser for rookie to tune without fuel injection. Am I right?
Advice please, anyone done this and has experience please let me know.
I'd fix the electrical first then see what it needs. Don't throw a bunch of mods without a good working car first. I wouldn't associate the alternator with the ECM. Maybe you got bad alternators, maybe you have a bad battery or bad battery connection that stresses out the alternator. It seems like I see a pattern that people have stuff they don't understand and try to toss a carb in to hope that all the problems go away. If you have a charging issue, I am not sure how the carb will help.
First piece of advice is to post your location. That way if somebody is nearby they might be able to help.
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From: Lakewood Ranch Florida
I am in west florida, Sarasota area. I have the battery alternator issue fixed now. Like I said only issue is when it has around a quater tank or less sputters making turns. I would like more power and would redo trans and replica rear end if and when it breaks to save up for Dana 44. My trans is an auto. Should I just rebuild current trans and beef it up a bit of look for something else used and rebuild. You are right I don't fully understand all this and that's why I'm posting. I just thought a rebuild of original L98 punched to 383 with carb would be fairly easy and fun. Plus power. I figured I'd solve my fuel issue when replaced fuel pump and filters during project. Am I way off course here?? BWY budget is around 3 grand and I plan on doing a lot of work plus have help from my club. THX This has been informitive so far but would love someone to say go for it or cut it out dummy and just rebuild L98!!
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From: Hartford WI
Like I said only issue is when it has around a quater tank or less sputters making turns.
I would like more power and would redo trans and replica rear end if and when it breaks to save up for Dana 44. My trans is an auto. Should I just rebuild current trans and beef it up a bit of look for something else used and rebuild.
You are right I don't fully understand all this and that's why I'm posting. I just thought a rebuild of original L98 punched to 383 with carb would be fairly easy and fun. Plus power. I figured I'd solve my fuel issue when replaced fuel pump and filters during project. Am I way off course here?? BWY budget is around 3 grand and I plan on doing a lot of work plus have help from my club. THX This has been informitive so far but would love someone to say go for it or cut it out dummy and just rebuild L98!!
I would like more power and would redo trans and replica rear end if and when it breaks to save up for Dana 44. My trans is an auto. Should I just rebuild current trans and beef it up a bit of look for something else used and rebuild.
You are right I don't fully understand all this and that's why I'm posting. I just thought a rebuild of original L98 punched to 383 with carb would be fairly easy and fun. Plus power. I figured I'd solve my fuel issue when replaced fuel pump and filters during project. Am I way off course here?? BWY budget is around 3 grand and I plan on doing a lot of work plus have help from my club. THX This has been informitive so far but would love someone to say go for it or cut it out dummy and just rebuild L98!!
I'd get the trans done at Rossler Trans in Girard OH. Recommended by Lingenfelter and I beat on it every day, several times a day for 3.5 years before it broke the Sun Shell Gear and when we rebuilt it, we used "The Beast" sun shell gear.
I have would say get your car 100% first. Fix the fuel issue. When you have no issues, have the motor out and bored and stroked. When it comes back, get a tune and make sure it is running good. Next preparation is for the trans. It WILL take a crap. When I asked JL how long it would last with his 383, he said 1 year. NO MORE. 6 months later, it died. Why that sequence? You see, your trans TC will have to be matched with the engine and you don't want to put a good TC behind a weak trans. After that, you can worry about the rear end.
I would say fix the prolem and cut it out before you fix the engine.
Slingshot
Joined: Dec 2001
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From: Charlotte NC
Just looking to freshen up the motor. Currently only issue is when the is a quarter tank of gas or less when you make a 90 degree turn from a light for instance it sputters like it's not getting enough fuel. But goal of project is to have a nice reliable motor with maybe some additional power for not a lot of cash. And I love that corvette, it's the first one I ever purchased!
If the car is running well and not burning oil then why go for a complete rebuild? Just fix the stuff that is broken or giving you trouble and then enjoy the car.
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From: Lakewood Ranch Florida
Coolly I'll work on that and then look into pulling the motor after. Would you go with a carb or keep fuel injection when I do get to the rebuild? I've never done anything like this but I would think if I went with 383 I'd have to spend $$ updating injection system and computer right? Cheaper with a good carb?
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From: Lakewood Ranch Florida
I want to upgrade car and have time to do a project. Also I have a Z06 and want the C4 not to feel slow next to it in the garage!! LOL. So no reason to do this I'm just having fun and want to learn about motor rebuilding. Your right the car is GREAT and would still be if I just fixed the fuel issue and kept having fun with it but I just can't leave anything alone!
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From: Maryville Tn
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Stick with stock if you want reliability. Carbs are old school. Stick with FI. Good luck with your build. 
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From: Lakewood Ranch Florida
Thanks, is it going to cost me a lot to upgrade injection system? Probably need new injectors that have more flow and rails? And what about the computer it will have to be tuned also correct? All that work will have to be done by a professional tuner right? Any idea on cost? Oh I will probably upgrade to a hot cam kit too so take that into consideration when or if you can give me an approximate price.
If anyone has done this project or sonething similar can you give me an idea of how much you spent. I do want to do as much work on it as I can. Keep in mind this is my first time tackling this kind of project. Thanks everyone for the input. More and more it seems I might be best to fix my fuel issue and do a stock rebuild (rebuild kit I've seen them out there for the L98) and just be happy with that and save a lot of money. Plus I'll still get the experience of rebuilding a motor which is really what I want to do. Want to know/learn more of mechanics. Tired of my regular desk work want a man project!!
If anyone has done this project or sonething similar can you give me an idea of how much you spent. I do want to do as much work on it as I can. Keep in mind this is my first time tackling this kind of project. Thanks everyone for the input. More and more it seems I might be best to fix my fuel issue and do a stock rebuild (rebuild kit I've seen them out there for the L98) and just be happy with that and save a lot of money. Plus I'll still get the experience of rebuilding a motor which is really what I want to do. Want to know/learn more of mechanics. Tired of my regular desk work want a man project!!
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From: Hartford WI
Coolly I'll work on that and then look into pulling the motor after. Would you go with a carb or keep fuel injection when I do get to the rebuild? I've never done anything like this but I would think if I went with 383 I'd have to spend $$ updating injection system and computer right? Cheaper with a good carb?
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Joined: Jul 2004
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From: Hartford WI
Thanks, is it going to cost me a lot to upgrade injection system? Probably need new injectors that have more flow and rails? And what about the computer it will have to be tuned also correct? All that work will have to be done by a professional tuner right? Any idea on cost? Oh I will probably upgrade to a hot cam kit too so take that into consideration when or if you can give me an approximate price.
If anyone has done this project or sonething similar can you give me an idea of how much you spent. I do want to do as much work on it as I can. Keep in mind this is my first time tackling this kind of project. Thanks everyone for the input. More and more it seems I might be best to fix my fuel issue and do a stock rebuild (rebuild kit I've seen them out there for the L98) and just be happy with that and save a lot of money. Plus I'll still get the experience of rebuilding a motor which is really what I want to do. Want to know/learn more of mechanics. Tired of my regular desk work want a man project!!
If anyone has done this project or sonething similar can you give me an idea of how much you spent. I do want to do as much work on it as I can. Keep in mind this is my first time tackling this kind of project. Thanks everyone for the input. More and more it seems I might be best to fix my fuel issue and do a stock rebuild (rebuild kit I've seen them out there for the L98) and just be happy with that and save a lot of money. Plus I'll still get the experience of rebuilding a motor which is really what I want to do. Want to know/learn more of mechanics. Tired of my regular desk work want a man project!!
That said, how often do you think you are changing things? I haven't done tuning for several years now. I don't believe you are going to change things on a weekly basis so dyno tuning is a one shot deal for quite a few years unless you are changing cams or heads on a weekly basis.
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From: Hartford WI
When I see a carb, I walk past. My only issue is my lawn equipment has carbs on it which I curse at every time I use them. I sold the wife's ATV for a newer one after it was 1 year old. Why? So I can ride it at 10000 feet today, go to 5000 feet tomorrow and sea level the next day without having to screw with jetting. I bought a pair of 2003 GTX Seadoos because our older ones were ok but carbed. No more carbs for me where economically feasible.
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From: altered state
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When C4 gas gauges read low they are LOW on gas. Keep more in it bet that fixes your problem. Know electric pumps like to be submerged in gas to keep cool. Run them low a lot and they burn up quick.
It costs hardly anything at all to upgrade your bottom end to a 383.
Hotcam would work, see what you can do about upgrading your heads though, intake too.
You could always do the bottom end then reuse what you have til you can afford the better top end parts but easier to do in one shot.
You can reuse your computer, tunes are around a few hundred give/take. Im a carb guy but honestly get the EFI nailed down right and youre ahead of the game. All the way around they are just better. The FIRST intake would work real well with the cubes and the smallish cam. Theres other choices also but thats a start.
It costs hardly anything at all to upgrade your bottom end to a 383.
Hotcam would work, see what you can do about upgrading your heads though, intake too.
You could always do the bottom end then reuse what you have til you can afford the better top end parts but easier to do in one shot.
You can reuse your computer, tunes are around a few hundred give/take. Im a carb guy but honestly get the EFI nailed down right and youre ahead of the game. All the way around they are just better. The FIRST intake would work real well with the cubes and the smallish cam. Theres other choices also but thats a start.