Well Ross, I have a machinist back ground, some skill at math and I'm inquisitive. I've never been someone to do something, just because someone else does it or it's the popular thing to do. If I'm interested in something, I always want to know "why". I've always had a racers mentality, from as far back as 12 years old and look for that last bit of advantage or strive to get as close as possible to the rules, w/o braking them.
Compression is one of the best and fastest ways of making HP. From what I've seen, most do not consider the area, from the top ring to the top of the piston, in their calculation of CR, leaving 1 to 1.5cc out of their total chamber. As a racer, there is no way I would leave .07 of CR, off the table. If X CR = some amount of HP, then X/CR = another amount.
I did not do this for HP, I did this for quench and to keep my CR below 10/1, knowing what my actual CR is so, I can use most pump gas, with my valve and ignition timing. I did this thread, because I thought it would be interesting and valuable for others and I was hoping that I could get some blanks filled in.
Frank, nice thing about the internet and the garage, everyone can do their own thing. I say have fun, I don't need to know why, but certainly can see what you are doing with the pistons proud and how you got there.
Guys who build nice stuff think about crevice volume, and if you do too, better. In some cases I have even played around with squish/dish surface area ratio and D-cup vs dish calculation, and realized in that case, it didn't mean much at small numbers. I am with Brent though that there is more substantial improvements to be made with machine work, but your circus, your monkeys to butcher an old Polish saying. (The Polish saying is "not my circus, not my monkeys", meaning none of my business...)
As an input, I do not know if your calculator adjusts the top ring land height to the negative deck clearance, but if you are getting that fussy, may want to run the volume numbers yourself and see
In the end though, Brent gave you some good info. Our comments may not apply to the actual head gasket discussion, but it's good info, and it's free. Guys like him, me and other builders on this forum making good power on small cams, pump gas, high vacuum really look close at how the block is machined to get there and are passing our experience. I just wanted to point out you may not be as consistent as you are calculating without a squared block and mains, along with the other things Brent mentioned
I meant it though, and not as a jab, Rock Auto is cheap, buy every option, measure, smell, taste, you name it, and tell us ... love to hear what you find.
