I have a 95 dx hatch with cx motor the head says 93 in a circle so I'm guessing it is a 93? Would it have 2 or 4 valve reliefs per piston?

 

I don't know of any conclusive way to tell without pulling the head. At some point Honda changed the part numbers for the pistons, if you check now they all use the same pistons as a D15B7 (which has 4 valve reliefs) as a matter of fact until not that long ago I didn't believe any D15B8 had 2 valve reliefs. I have since seen pictures though, and they do exist.

Here's what they look like btw:



Never noticed it until now, but the PM8 2 valve relief pistons have a dome on them, plus they don't have the extra valve reliefs obviously, I'd have to say that would have a pretty big impact on the compression ratio.