CR calculation, deck height/effective dome volume?

Looking at the UEM caclulator, the Piston Head Volume is the volume of a dish into the piston top, or the valve relief volume in a flat top. It does not vary regardless of where the top edge of the piston ends up relative to the deck.

And you are right to use -.036" as the deck height in that calculator with the piston top above the deck. This would be related to the compression height listed for a given piston.

Using your numbers of:
- 63.6 cc chamber volume (Cylinder Head Volume per UEM)
- Valve reliefs of 7.5 cc (Piston Head Volume per UEM)
- Top of piston .036" above deck (-.036" Deck Clearance per UEM)
- Gasket of .040" thick and 4.18" bore
- 4.07" cylinder bore diameter
- 3.31" stroke
With UEM calculator, I get 10.745
With the Pat Kelly calculator, I get 10.744

At this point, I can't explain why you get lower numbers with the same inputs plugged into the UEM calculator. Can you list all of the inputs that you put in the UEM calculator in the same way I listed above, so we can compare numbers directly?

OK on the street use, and I would be lowering the SCR too, to around 10, depending on the exact cam, and shooting for the range level of DCR.

You look to have gotten a lot of chamber volume out with the valves (and maybe higher seats? I dunno), and lost probably about 2 cc's with an approximate .010" mill.
I think i'm starting to get my head around this, finally. 4.070 area x .036" = -7.675cc for my EDV. With the piston head volume at 7.5cc, I'm basically at zero. The 2.2cc mistake threw me off a bit. This time I used the exact numbers you did, which also put my CR right at 10.745 w/ UEM's calculator. The more I think about it, I see how my measuring came out wrong. I have a basically new set of Milodon(?) tulip-head valves that i'll swap in to see how they affect the chamber volume, or I have a rebuilt set of 2.02 J heads (also with tulips) that are a whisker under 70cc. Amazing what a shave and some valves will do.