Built motor compression

[Frozen240]

For everyone who has built their Ka, I was wondering what kind of compression you had when you first got the motor, before break-in, and what you ended up with after break-in. Any difference?

The reason I'm asking is that I'm getting my engine back soon and I'd like to know what kind of numbers I should expect. I'm using Arias 8.8 CR with a 0.5mm overbore. Felpro HG, and the block has been decked.

[npaulseth]

Well, everything will come into play. How much your block has been decked, how much has been shaved off your head, if any. How thick your HG is, blah blah blah. You should hope for 170-185 psi in all cylinders. Overall compression maybe isn't so important and it being the same in all cylinders.

[Structure240sx]

also cams play a part, if they have overlap

my motor already had 10k miles on it when i put it in. 9:1 ross pistons .040 over ( i think ) stock cams my compression is 175psi

[npaulseth]

also cams play a part, if they have overlap

Yup, but generally turbo cams don't have any overlap, so us 4-banger guys don't have to worry about that.