slomarao

iTrader: (6)

Trying to figure out how much I need to mill my heads to get to 11.6.1-11.7.1 compression. I will be using a .028 impala headgaskets, ive searched and cant not figure things out.


from what ive read around .025?

vanilla89

iTrader: (8)

is this a stock bottomend??

slomarao

iTrader: (6)

357

speedpro slug, 5.7 scat i beam, stock crank, studed main

slomarao

iTrader: (6)

anyone??

RamAir95TA

iTrader: (2)

The head gasket should be the variable, not how much you mill off of the heads.

slomarao

iTrader: (6)

I dont understand exactly what you are saying?? confused

RamAir95TA

iTrader: (2)

It is not practical to mill X amount off of the heads to achieve your desired compression ratio when all you need to do is adjust the head gasket thickness.

Have you had your current combustion chambers CC'd?

slomarao

iTrader: (6)

No they are still stock, the reason why I plan to mill them is because I dont think I am going to jump from 10.4.1 to 11.6.1 with Impy gaskets alone.

from the thread searches Ive done the thinest gaskets are the impy ones. Is there anything thinner than that?

speed_demon24

iTrader: (6)

The bigger bore is going to up the compression too. Plug your #'s into a compression calculator.

RamAir95TA

iTrader: (2)

If they have never been milled before, go ahead and mill them down to clean them up. You can get thinner than .028 - Cometic gaskets can be ordered thinner, but they are quite expensive. Any work done to the block? What's your deck height?

RamAir95TA

iTrader: (2)

I think you meant to say the larger bore will drop the compression.

slomarao

iTrader: (6)

Well I have a knock in the bottom end. I am pretty sure its a wrist pin or rod bolt, Ive had a few friends with 5-6 f-bodies and vets all check it out and that is what they think my issue is.

I am not sure on the deck height or anything else really(i would say they are stock). The heads and intake I have were done by one of the guys who has 5 cars back in 96.

I know he gasket matched them and did a valvejob. since they are opened up a bit I think they would drop the compression and than I will be on a 40 over bore dropping the compression further.

speed_demon24

iTrader: (6)

It will increase the compression...

speed_demon24

iTrader: (6)

You probably should have done that before you made this post.

RamAir95TA

iTrader: (2)

Definitely.

Now I'm going crazy. Hah. Oh well. You win.

slomarao

iTrader: (6)

If the bore gets bigger how does the compression go up?? its going to be a bigger chamber??

You wana shed some light on this??

brucer

you need to measure how far the pistons are in the hole first, then go from there..

if someone else built the engine, they may have decked the block to start with, you need to make sure either way.. then you go for the quench measurement... think it would be more important than compression alone..

slomarao

iTrader: (6)

no the shortblock is stock. I really doubt someone decked the block, I got the car when it had 57K on it.

brucer

i thought you said it was bored? if its a 357 its .040 over... thats not stock.. block couldve been decked, you need to check it to make sure..

anyways,
to figure the compression correctly you need to know how far the pistons are in the hole to start with.. then you go to the compression calculator..

slomarao

iTrader: (6)

It will be this week. otherwise stock, i was talking about the current deck height.