89FormulaLS2

iTrader: (1)

Last spring I bought Mike's (PurEvl) heads that Jeff Ott ported for him. Getting ready to put them on the engine very soon - just have to get some new pistons first.

My original plan was to build this car NA with a Z06 cam, but I decided to go with a TR224/224 112lsa instead. I don't have enough P/V clearance, so I've got to get new pistons to compensate.

Now however, I'm looking at perhaps throwing on an STS turbo kit, possibly around the beginning of summer. If I use these heads (milled .050) my compression will be WAY to high - I think Mike said he had 11.2:1 CR with a 224 cam when they were on his car.

Trying not to go TOO far overbudget here, I'm thinking of getting some dished pistons to lower the compression now. My question is, how low should I go with the CR, and what size dish will I need to do it? I'm going to want to have daily drivability between now and summer with NA, but then be able to run decent with the FI later on. OR....... am I going to be that much better off by just changing either heads and/or pistons later when I mount the STS?

Thanks,
Adam

Slowhawk

iTrader: (12)

You need a definite plan.A forged piston is good for FI but those heads are not.They are milled too much to hold the cylinder pressure the STS will make.So it would be better to sell them and buy 72cc AFR's.Then rebuilt the lower end with forged pistons/better rods and a good rotating assembly balance.

89FormulaLS2

iTrader: (1)

I was afraid you might say that.

OK, I guess I'll just get some pistons for now to solve the P/V clearance issue, and then change them again later. Due to budget constraints, I'm going to have to do this in stages.

Now, you and others have said that the STS will run fine on a stock engine - will I NEED to replace the entire bottom end when I put on the 72cc heads? If so, then I will just put my stock heads back on when I install the STS, and then upgrade the bottom end and heads at a later point.

Don, how will my NA build (Mike's old heads and the TR224 cam) stack up against a stock heads with the STS in terms of power output?

LSonederfull

Hey, Jeff Ott here, did you verify your ptv clearance? I'm not sure you should have a problem with those heads and 224* cam. Those heads should put out 410-420 rwhp with all mods and Slowhawk tuning. Those particular heads had the highest flow of any LS1 #241 castings i've done. Easy 11 sec. heads especially a4. FYI

89FormulaLS2

iTrader: (1)

Mike warned me when I bought the heads to check P/V clearance, 'cause he had to have valve reliefs on his pistons. We used modeling clay to do a check on it, and the valve DEFINITELY makes contact with the piston, so I've got to do the same as Mike.

Thanks for chiming in though, Jeff. I'll be running an M6, but I sure wouldn't mind seeing 11's. Doesn't hurt my feelings to know those are your best heads, either.

I'm also doing a lot of mods to the suspension and dropping 150-200 pounds due to the lower weight of the LS1 + tubular components. Should be somewhere in the high 3200 to low 3300 pound range when done. Hopefully I can make her hook well, and then have some fun!

Don - when Bruce finishes up the swap, should I drive this from S. Carolina up to your place to get it tuned, or do you think I'll need to trailer it up?

Adam

Slowhawk

iTrader: (12)

You can actually send me your computer and I'll mail order a tune that will get you in the ball park Then you can get the car to me for the final tuning.

89FormulaLS2

iTrader: (1)

Sounds like a plan. Is "1761 FallRiver Ave Seekonk, MA 02771" the shipping address I should use?

Thanks again,
Adam

Slowhawk

iTrader: (12)

Yes,but make sure you know exactly what ig going in the car first(motor,heads,cam)before you even think about sending the computer.That way I don't have to keep changing it.