LT1 E85 Compression Question

[Gregs_gsxr]

just like boost addict said deck the block/head gasket can get you about 1/2 point/ and pistons. i would split the differance between decking the block and a thinner mls gasket. porting your own heads huh. word of friendly advice buy a cc beeker and make sure ever runner has the same cc runner when your done or you could throw your cumbustion off. like 2 cyl getting more air than the others. the crank will not like you at that point.

I cant explain how I learned so in so little time from this guy

[xDetroitMetalx]

Personally running 12.5:1 on 93 octane, that's the beauty of reverse cooling heads. You could easily run over 13:1 or more if you really wanted too. As for the max? I don't know!

Best information thus far is Joe. I would save and do the build how you want it the first time. I also agree with not porting the heads yourself. Either seek LE/AI or aftermarket.

[PWND3r]

What did that car end up running Joe?

The car really varied. I never got a clean pass. The 60's were 1.8-1.9. On motor varied from 11.7 to 11.3, spray was only on a 100 shot without a tune from 11.3 to 10.8. After Steve tuned it, I only took it to Lapeer and I got tech'd and wasn't able to run. Never took it out with the bigger jets.

It pulled hard after the 330' mark. But the 60's were shit.

[DETROITMUSCLE]

The car really varied. I never got a clean pass. The 60's were 1.8-1.9. On motor varied from 11.7 to 11.3, spray was only on a 100 shot without a tune from 11.3 to 10.8. After Steve tuned it, I only took it to Lapeer and I got tech'd and wasn't able to run. Never took it out with the bigger jets.

It pulled hard after the 330' mark. But the 60's were shit.

damn talk about some untapped potential that thing needed some suspension and a tire bad.

[PWND3r]

damn talk about some untapped potential that thing needed some suspension and a tire bad.

It was a true stock suspension. The only thing it had were control arms, torque arm, 12 bolt, poly bushings, panhard, stock sway, stock springs, stock shocks.

I never cared to dial it in, I mostly street drove it for fun.

[DETROITMUSCLE]

I wouldn't call that stock suspension lol I still have stock shocks and springs on my car, although its an auto. Did you ever run a slick on it? If not then thats half the problem lol a radial on a 6 speed car is tough to dial in without some adjustable shocks up front.

[PWND3r]

I wouldn't call that stock suspension lol I still have stock shocks and springs on my car, although its an auto. Did you ever run a slick on it? If not then thats half the problem lol a radial on a 6 speed car is tough to dial in without some adjustable shocks up front.

Stock suspension in my book, if there's stock shocks, springs, sway bars. Car was on 6 year old ET streets that came with the car on 20psi.

[jgardner]

word of friendly advice buy a cc beeker and make sure ever runner has the same cc runner when your done or you could throw your cumbustion off. like 2 cyl getting more air than the others. the crank will not like you at that point.

Yep, each port is within a half cc of each other

Combustion chamber is a touchy area. I wouldnt feel safe changing the shape of it myself and assuming they are all the same. Or that my new shape was better than stock. (Then again I am not an expert) But by polishing one different than another could change the way it dispurses the combustion. Most likely not in a good way. MOST of the time alot of R&D and flow bench/design time goes into making heads work. Hence why it is so expensive to have somebody bolt them down and run a CNC program on them.

Yeah I'm not really touching the combustion chamber, just some VERY light polishing...although it seemed more like cleaning than actual polishing with how little it was affected

I am not trying to be an ass and preach to you but I got this speech when I was thinking of touching up the heads for my current build. I wanted some light porting done and have the combustion chambers polished. Assumed it easily could have been done myself. I learned it is much better to have it done by a professional on professional equiptment to assure the flow/mixing of air/fuel is the same in all 8 cylinders. Even if what you are doing is minor.

Again I am in no way saying you are incapable of doing it yourself and making power with them. Plenty of people do it. I guess it is just how confident in your abilities you are. There is just alot to consider when it comes to effing with your heads. I would hate to see you have problems with it.

Not taken the wrong way at all. I was very hesitant at first, but me being me I did a buttload of research.

Bit of an update though: The heads are all ported/polished and just got word from the shop that they're done being cleaned. And my spring locators are FINALLY shipped after being on backorder for almost a month. Hoping to have it back together within a week or two (assuming I can find time to work on it lol). Can't wait for dyno day to see how it runs!