Long valves on W2's with .600 lift?

Wyrmrider said
how much compression woul you targer YR?
just getting new race tech pistons 200 gm lighter than the old ones
I have not seen final cr calc yet\
I guess he can play with gaskets but high compression sbm have always been hard to seal for me
I used to o ring but today Cometic or what else works?

I'm not sure what to say about compression ratio. If you are traction/chassis/tired limited I'd think to help get it off the corner you may reduce the CR a bit. If you can get it hooked, I'd shoot for 13:1 or a bit more if you can do it, WITHOUT killing air flow.

When the dome is in the way (especially once the valve is off the seat and moving open...not so much at and around TDC) it changes the flow pattern of the air getting into the cylinder.

It shows up on the carbon patterns on the piston and the chamber and significant clean spots. It was believed (and still is by some) that the clean areas are caused by "fuel wash" but the fact is there is no fuel or air in that area, so there is no carbon residue.

That's why if you have the open chamber heads (which I think you do) I always stick the deck of the piston out as far as I can and then measure for CR. If it's too high, I reduce the dome to get it where I want.

Using my questionable memory, my 11:1 engine right now has a .150-.187 dome (I can't remember which it was and I'm on jury duty so I don't have time to get the build sheet) which is pretty small. But I'm out of the deck .045 (IIRC) or close to that. If I had used a zero deck, the dome (again IIRC) would have been closer to .200-.225. It also makes th piston lighter and reduces crevice volume by a decent bit.

All things to consider.