Hey guys have been doing alot of research but what to hear what you have to say... I have a 90 camaro with a built 383 stroker compression is 10.8:1 and I want to run twin turbos.. I heard if I change out my head gaskets to some super thick ones maybe bring the compressiin down to 10:5:1 or alittle lower I could run twins at like 12 lbs but I'd have to run meth. Or e85 was wanting to stay on 93 pump but if I have to I'll run e85 no meth tho

 

Just run it on e85.

 

I guess I'll just have too

 

Can u get new heads with larger chambers or have yours opened up some

 

Yeah 9.5:1 would be a lot better for twins.

 

I feel like you could get away easily with 12psi using methanol/water injection as well

 

For racing yeah, but for the street.....12:1....+boost. ....idk

 

My bad, 11:1

 

These days alot of turbo build recommendations are moving towards 10:1 compression builds thanks to all the options we have for fixing octane, everything from intercooling to methanol and alternative fuels and better cooling options will help make it safer. You could always turn the boost down a little bit as well if it gave you trouble.

I believe there are 10:1 compression builds using 25psi of boost on methanol, I don't see a problem with 11:1 using 12psi on methanol. It is NOT optimal. It is NOT recommended. I am only saying that it should fly if its the only option without tearing up the engine.

 

Have to keep that in mind. .. thanks.
I will be running water /meth. With 93 octane pump gas, but with 32 psi & up to 40psi available from the inner cooled F3 121a ( procharger ), I'm thinking that 9.5:1 will be pushing it.

 

I would have to agree with Orr89RocZ, open up the chamber's of your head's. This ( if done right ), will do 2 things for you. 1st, lower compression, 2nd unshroud the valves ( which will help by allowing them to flow better ), this will up the efficiency of the engine.
Diggler, is also onto something. ...e85 will give you a better power level, but if it's not readily available. .. water/meth is the way to go.

 

Problem is you say 12 psi now but that will get old quick and soon will become 15+ psi. It happens to everyone.

Build the compression right so you can grow into it more. While 10.8 or so can work with meth inj and intercooling at 12 psi, you will have a safer more forgiving combo capable of more boost power with slightly lower compression

 

Hey Orr, I know you've been around this stuff a good bit. ... what do you think about my setup and what would you change?

 

Dart iron eagle tall deck, std. 400 bore, 3.8" stroke (406 ci ), Diamond pistons w/1.205 c.h., 6.200 rods, raised cam bbc journal , solid roller 850ish lift, around 278/288 dur. @.050, morel solid roller lifters, RHS 14° heads, top line 2 piece single plain & c&s 900 cfm blow thru carb.

 

Oh, Procharger F3 121a, inner cooled

 

I think youve got a 2k+ hp combo. Only change I would suggest it putting it in my car.

 

LOL! THANKS DIGGLER, that's what I'm shooting for anyway.

 

I would rather see efi lol but seems good. I dont know much on carb sizing in blow thru. Na motor would see something over 1000 cfm carb i would think on something like that.

Watch the timing on 14 deg heads. They pretty efficient chamber it wont need alot of timing

But yeah that combo has alot of power potential. 1.205 comp height piston is good but maybe alittle taller height to get ring lands down more on big boost. I run a 1.125" and doin well but not that much power compared to a combo like that

 

Cool.
I've done some research, talked to c&s that is what they recommended ( said they did one for a similar combination, it made 2300+ on dyno ), Diamond said that in order for them to build a dependable and safe piston, they wanted at least 1.200" c.h.. so at 1.205" it leaves me .020 in the hole.
I've got a set of pro1's at Chad Speier's getting worked for a 422 cid sbc. ... probably have him do the 14° heads as well.

 

I wish that I could afford to go efi, but for now a blow thru will have to do.

 

Yup 1.200 is good. Just keep heads sealed on block and it should make steam

 

That's a whole other issue ain't it.... any suggestions?
Copper and O-rings? Studs of course. ..

 

it would make over 2k with cometics. i know of an LT1 that made 1900 (not a misprint) with them.

your iron eagle block has the extra tall deck height if im not mistaken that would help you out on the piston issue.

 

Yes, the tall deck measures 9.325", with a 3.8" stroke (1.9" measuring for the rod), 6.2" rod (piston guided)& 1.205 compression height for the wrist pin, leaves it .020 in the hole.
Custom dished ,forged & double hard anodized Diamond pistons .... are the plan.

 

Sorry OP.... WASN'T TRYING TO STEAL YOUR THREAD. ...
it's just a few questions ( like you ), that I was trying to get.
I'll just keep my pie hole shut for a bit, lol.

 

Thanks again Orr & DIGGLER. .. I will start a thread when I can finally get around to building it, ( not just planning, lol).

 

If you wanted to save some money on valvetrain, likely could get into 18 deg heads cheaper than 14's if you dont already have them. Make good power either way lol

 

Bump