Im thinking about possibly having my 1985 L-98 rebuilt in the next year. Does anyone have any ideas? Prices? Mods to do while being rebuilt? Any comments appreciated. Zak.

 

Your budget is everything.

 

Thats what Im wondering...how much will a stock rebuild cost?

 

Depends on who does it, what you need, where you get the parts, and what parts you use. What's wrong with your car that you feel needs rebuilding?

 

Well I just read your other thread where you said you need new valve seals.

It's too bad you don't live close to me, as I could have shown you how to do this job yourself (just buy the parts, I've got the tools). I've removed the heads on my car and pretty much got the process down pat. Perhaps you can locate an experienced forum member in your area to help you pull the heads and save money.

When your heads are off, you'll have a good chance to inspect your cylinder walls for wear. Proper engine oil changes can go a long way. Even at about 140K miles at the time, my cylinder wallls showed no wear or damage, and had about 200 PSI of cylinder compression across all 8 holes. Heck, I could not even feel a ridge line towards the top of any cylinder.

 

Well, its an 85 with 108,xxx miles. It needs new gaskets/seals. It doesnt run just right, it idles weird, and sounds like its missing. Overall, its just old.

 

That still don't mean you need to rebuild the whole engine. You've already said you got oil leaking past your valve seals and fouling your plugs. So obviously that needs to be taken care of. Unstable idle and missing can be a number of things not requiring the whole engine to be rebuilt.

You can do a compression check, or better yet a "leak down test" which will tell you the condition of your pistion rings. If your bottom end tests out fine, just freshen up your heads and get back on the road. Then determine how you're going to want to use the car, set your goals, and choose the parts accordingly. Again, your budget is everything.

 

Can you help me with some of this stuff? I want to give my engine more horse power. What would be the best setup for an already stock L-98 for the best gain, and cheapest? I would not be able to go over $800 probably. Thanks, Zak.

 

Seriously, I would first take care of that cylinder head issue and establish a good baseline. Get your car running right then worry about major mods. You can't do anything serious for $800 anyway.

I would use the money you have to fix your valve seals and get your car running right first. If that's all the money you got, you're going to have to find a local forum member to help you pull the heads. This is not hard, but labor intensive. If you have a shop do that for your it's going to cost you more than you have. If you do the labor yourself, and drop the heads off at a reputable machine shop, you $800 budget is plenty for that and heads gaskets, etc to button her back up.

Long tubes and new exhaust comes to mind. The stock headers are very restrictive. Once you start talking about rebuilds, intakes, cams, rear gears, etc. the price jumps substantially.

 

Hey man, I'm in the Dallas area with an 85 of my own. I'm pretty in deep with my rebuild right now, but I don't mind helping you out any. I've already done valves seals previously on this leaving the heads on the block. Let me know if you need a hand.

 

How did you keep the valves from falling? Pressurised the cylinder? Special tool?

 

Yeah, I just set the piston TDC and filled the cylinder with air. I have a leak down tester, so I just took the hose off it and used it to keep the valve up. There's also the rope trick, but I didn't do that.

You can even buy the little hose for like $10 or so at a parts store.

 

An engine rebuild isn't going to fix the idle.

If you want to actually know the condition of the motor, do a leak down check. Way to expensive to guess at it. And if you ask a mechanic, "Is my engine fine or should I pay you $2000?"... you know what the answer will be.

 

diagnose your engine,
do a compression test.
then do a leak down test.
while doing them have a note book and take exacting notes on all cylinders and be percise about them. it will tell you alot about your engine, you just have to figure it all out.

my 72 pontiac was running like a dog, **** poor performence, weezing and coughing, backfiring and stalling. I thought it was dead 4 sure.
so I borrowed my buddies compression checker kit. my pontiac 350 block 2 cylinders on the driver side had 50 or so psi in them, all the rest of the cylinders were checking at about 150 psi. it led me to believe that I had a blown head gasket. - but I was wrong when I put the leak down tester on them those 2 cylinders held some preassure , but it was escaping slowly. - I checked all around the coolant system looking for the air leaking out of the 2 bad cylinders I was testing. none was found. so I started checking for the air in other places, the dip stick, the pcv valves, diddnt find it anywhere, as I walked around the back of the car I felt the air coming out on my leg, out the driver side exaust pipe. I was like what the heck? - it turned out that my exaust seals were trashed on those 2 bad cylinders and the exaust valves them selves had holes burned thru the valve. that was where all my cylinder preassure was going. right out the exaust. -
by doing the simple compression test, and the leak down test, I found out my problem and it was realatively easy to fix.
if I diddnt take the time to do those things, I would of just got a whole new motor for the car, but the bottom end was in great shape, I just needed a valve job and some new valve seals.

 

Yeah, Id appreciate that.

 

I just threw a rod in my engine so I called around for prices on engine and also rebuild engines and this is what I found. Remanufactured long blocks are 1500 short blocks are 1399. To have an engine rebuild it was about 1800 about 2000 if you want it bored (which can be up to 60 over at same cost I suggest 30-40 over) The rebuild give you pretty much new everything except crank and heads while the head do get rebuild.

 

That would be a reletively easy fix that all you would need to do is take off your valve covers, get an air compressor adaptor, and screw it in where the spark plug goes to keep pressure on your valves while the piston is on the compression stroke(assuming your valves have decent seats). The only other tools you would need would be a spring compressor, and a pair of tweezers to fit the tiny squared o-ring. I am not sure whether the 350's in corvettes use the umbrella type seals in addition to the o-rings or not, but it shouldn't be a problem to replace them as well since you have to remove the keepers anyways...just remove the spring and the old o-ring, replace the umbrellas, replace the spring, put the new o-ring around the valve stem(it has square edges, so make sure it's not twisted when you get ready to replace the keepers), then move to the next valve. As stated earlier in this thread, I would do a compression check to be sure the work isnt in vain. As a rule of thumb, the pressure difference between your lowest and highest pressure cylinders should not vary more than 10%. I have done a few of these and have got the labor time down to about 2-2.5 hours. $10 in parts and a bit of your time = big$$ saved and a big difference in the color coming out your tailpipe.