gavhowe

I have a shape cylinder head D16z6, can i mill the head to increase the compression, if so how much. i know changing the piston would be a better solution, but as i have this spare head thought i would give it a go. I can get the work done for free. I KNow some one out there must have done this what sort of gains would i be looking at and what would the compression go from to. Soz fo rall the ? but as i from the UK there is no help to be found over here.; thanks in advance.

Plan B

The head can be milled down or "shaved". The amount of additional compression that you will recieve is proportional to the amount the head is shaved. But I know of no formula for figuring this out.

gavhowe

Thanks mate, i just dont want in run in to problems with things hitting each other. that why i need some one with experience.

JD_B18CDX

In a perfect world, for every increase in compression point you get 10hps.
But increasing compression point also increases the chance of detonation.

gavhowe

What do u mean by every compression point.?

sohc_boy

lets say u have 9.5:1 compression than u go up to 10.5:1 that's 1 compression point.

gavhowe

Thanks mate i understand now what is the compression on a D16z6

Plan B

Well i've experienced bent valves from 9000 rpm on a shaved head with stock valve springs, and burnt valves from a shaved head with a little detonation mixed in.