I have done lots of research and my goal is to raise my B16A6's comp from 10.2:1 to 11.0:1. I intend using a Spoon gasket which raises the compression by 0.3. To get the other 0.5 approximately how much needs to be shaved off the head? My calculation is 0.02in, how correct is this?

And is it recommendable to shave off so much? Our pump fuel is 95 so I won't have a problem with detonation.

 

Looks about right to me.

 

I used the Spoon 2 layer hg, and Omnipower Flatface valves on my B16. They claim an increase of .3 - .5 depending on the motor.

 

supertech flat faced valves only bump up CR .005 per valve, so about 0.08 for 16 valves on your head, i don't think omni valves would do that much more for you, I wouldn't waste my money on an expensive spoon or mugen h.g., just get a felpro h.g. and use two layers, they are only about 60-70 bucks at autozone and are sold at some honda dealers so they must be decent quality. Also, don't mill the head too much, you never know if you will have to mill it in the future. I learned that the hard way. And what cams do you plan on using?

 

Thanks for the replies. I just want to clarify so that when I take the head to the engineers that I give them the right instructions - I need to double check that it is 0.5mm (0.02in) that needs to be skimmed - because to me that seems like too little. Is half a millimetre going to increase my compression by 0.5:1

I will be using either the BC Spec3+, S2S1 or the 63402's, still to decide what fits in best with my budget and goals

 

believe it or not .5mm is a decent size to mill off of something that has strict tolerances to begin with. .5mm and some flat faced valves should do u good. if u get new valves make sure the machine shop does a 3 angle valve job to reseat the valves in the head.

 

Thanks for your reply, it;s much appreciated