i just got my head back from the machine shop(shaved 30thous, 3 angle valve job, and port and polished) its a 2000 gs-r head by the way.. and i know stock compression on a gs-r is 210.. and when i checked mine after i put the head on it was like at 249 what would be my compression there?

 

You can't directly translate dynamic compresison (ie: compression test) into a static compression ratio. Cam timing, valve lash, ring integrity, combustion chamber shape and size, port shape and size, static ratio, etc. all play a part in the dynamic numbers you see on that gauge. Basically, the results you've just witessed are good. You want to see a rise in dynamic compression after head work.

If you want to know your new static ratio, it should be in the neighborhood of 10.7:1. I say "in the neighborhood" because the GSR doesn't have a round combustion chamber in the head so it's harder to figure out the exact changes brought about by milling. Furthermore, if the bowls were played with at all by the porter, than they could easily lower this ratio due to an incresed volume.

-Kevin