Bear with me as I go at this project. I have rebuilt engines before but only back to stock, and carburated.

I started a forum a some time ago when my dad purchased a 1987 Corvette. First we had starting issues and computer chip problems. After having that all ironed out the car spun the #2 rod bearing.

Fast forward to now, we are about to get everything back from the machine shop. We are making a few mods to the car but nothing that should be to radical, however being a fuel injected car I need the experts such as yourself to help me along.

I do have the FSM so I reference that frequently.

The block needed bored .030 over, valves needed replaced as the ridges where the keepers go were mushroomed over, so we are going with stainless steel hardened valves with springs to match.

in addition we are adding roller rockers to replace the stock rockers, putting new roller lifters in to replace the old ones.

the pistons will be forged flat top pistons and the cam will be ( I think as I can't rememeber off the top of my head is a .425/.465) specs say that this cam is not wild enough that programming the computer should be necessary, however fuel pressure may need to be increased. At what pressure should we set it at?

We have new injectors to go in this car (bought before the engine failed) they are Accel 24 lb injectors (for up to 300 hp at 9.5:1 compression or below).

I thank you all in advance for your advice,

I will keep you posted.

Tink

 

.030 over will result in a 355 cid displacement. Coupled with the cam and the injectors, you may want to consider port-matching the intake runners.

Are you staying with the stock heads? Are you considering headers and a better exhaust system?

To start, the OEM fuel pressure regulator should be OK, it's not adjustable. You can always go to an adjustable regulator later on. Replace the fuel filter and use fresh gas. I would recommend getting data from the ECM using data logging software which will help with any custom tune that may be needed later. If you have a good stock chip, install that in the ECM.

The stock throttle body will handle more than enough airflow for what you described. Clean the IAC or replace it. Also clean the TB and make sure there is no binding or excessive wear in the butterfly shaft.

The ECM controls timing so set timing to the factory 6 degrees advance and make sure the TPS voltage reading are right.

Consider some 1.6 roller rockers if you haven't bought a set by now. You will have to grind off the tabs on the inside of the factory valve covers for clearance. Look at Harland Sharp rockers.

 

You should buy Tunerpro RT and an ALDL cable so you can datalog with a laptop. The numbers will guide you in tuning fuel pressure and tuning in general.

 

Sounds like it will be sweet when finished!

Since many with L98's are considering rebuild or replace, would you mind sharing what your various machine shop charges were? I have not done a SBC for years..wondering what the machine shop fees have climbed up to. Thanks in advance.

 

I'm in the process of rebuilding the L98 for my 85 and so far, here is what the machine shop near me on Long Island has quoted:

Cylinder Head pressure test: $80 for the pair
Cylinder Heads pressure test and cleaning: $125 each
Engine Block cleaning and boring: $175 (includes new freeze plugs and camshaft bearings)

To the OP, what cam are you using (I was told a cam with 212/218 duration would work with my computer without a tune, not sure about the 87)? I have a Comp Cam picked out that's made for the TPI motor (206/212). Are you replacing the valve springs to work with your new cam? It was recommended for the cam I chose.

There really isn't much difference between building a carbed motor and fuel injected one. If you don't want to deal with an ECM tune, then you'll have to stay stock or close to it.

 

For your motor I would use hypereutectic pistons. They are plenty strong enough, they will be quieter, seal better, less expensive. I used them on my 383 years ago with many runs in the low teens. The motor is still running to this day with no problems.