hi everyone,

I've got a freshly built 1.6cvh with cosworth forged low-comp pistons, they have a comp ration of 7.4:1, done a compression test this morning only to get 120psi on all 4.

I know a fresh engine should be about 170ish, are my pistons making it this low or do I have a problem?

Thanks

 

was this on cold engine or warm. I think 170 is a bit high in my opion but not 100% sure. I thought about 140psi for turbo engines.

there is another thread going on this subject I suggest you jump in there.

 

mines averages 8.5 bar cold with your pistons in it

 

So that's similar to mine then, at least I know there isn't a problem. Do your's slap abit when cold?

 

123psi (8.5bar)

 

just a bit takes about a mile to quieten down

 

120psi is fine, and yes they will slap when cold.