ok i am building a mini me(a6 block y8 head).I know they are high comp motor's but i am going to buy rods and all with 8:5.1 comp psitons.I was wondering if i did that my comp would be around 9.1 right??

 

There is a compression calculator sticky at the top of this forum.

 

ya did that but i dosent let me change what comp pistons i am useing.

 

Sure it does, It's called Dome CC

 

You can figure out what dome cc you have by either reading piston specs that should come packaged with the pistons, or on the manufacturer website, or by figuring out the dome cc by fiddling with the applet on the known engine combo those pistons are good for 8.5:1 on, until you get 8.5:1.

It's so hard, it must be rocket science.

Say, did you order the pistons to match the valve reliefs in the A6 head, or the Y8 head? Are you aware how little timing the Y8 head likes? Or that the A6 head flows better, just swap camshaft pls kthx?

:P

Some of those Q's are trick questions... they don't mean what they seem to. A couple are honest to god real ones. The search button is in the toolbar at the top of the screen.

 

Ok i am putting the y8 head on it but ported and polished.So flow is out of the way,i did the compression calc and i must have fucked it all up casue i got 3.4:1 comp.the pistons i am getting are these srp 75.25mm,0.01 over size,stroke3.543, comp hieght 1.161,head cc 38cc, comp ratio 8.5:1 dome volume -6.8cc,
I did this all but i just need to know so i can have the machine shop guy know what he is doing.Please any help would be great.thanks

 

i think you are a we bit too confused to go building a motor.