DeadVet

Well heres the deal, i already searched and came up with 1 post that said the compression ratio of a a6 block with a z6 head was 9.9:1. I am in the process of trying to make 400whp but would like to know if 9.9:1 is the real compression ratio of this combo or is it something different. When i put this combo together i didnt know the compression was going to be this high, i was misinformed. Also when i had the motor assembled the machine shop cut .010 off the head and .010 off the block.

With all of that said does anyone know what the real compression ratio of a a6 block and z6 head in stock form and how much .020 ups the compression? If the compression ratio really is 9.9:1 would it be safe to try and make close to 400whp with that high of compression?

DeadVet

up

Katman

you should be fine with a 9.9 compression ratio and boosting...you might wanna venture over to the http://www.d-series.org forum..

crxracer2006

you should go all motor but, that compression will work for a little bit of boost but dont try runnin to much for 400whp you might want to get 8.5:1 pistons and then you should be able to boost the hell out of it

DeadVet

i already have everything on and am running 12psi right now. I am just going to take everything from my block and put it in a z6 block to bring the compression back down to 9:1

gnar kill

I am doind the same thing you are and I am also certain that the compression ratio is actually 10.2 to one (if you used the new metal headgasket which you should) but if you want anywhere near 400 hp from a SOHC you are gonna need new rods and low compression pistons anyway so I wouldn't worry about the higher compression due to the fact that a d16z6 and y8 come with dished pistons while the pistons in your 16 are pretty flat topped...that is just my 2 cents