Choosing piston

Idaho said

From another thread, I asked how the machine shop decides on a piston. We've determined I need somewhere in the 23 to 25 cc dish to arrive at 9.5 to 10:1 compression on a 408 stroker. He wants pistons there before boring to 0.30 over.

Got this reply and I understand it except how is deck height after milling determined without pistons? I've seen technical ways but do they actually do it?

Click to expand...

"Exact" is like within .006 lol. Jk
Compression height/pin height.
And that's based on a rod length being blue printed, a stroke blue printed, and an OEM deck height being blueprinted.... aka perfect.

There is always a hair variable.
So the rod is .002 shorter.... and the deck is taller by .008..max and .003 at the small end.. but the machinist just squared it and took .007 at one end and .002 at the other.. and the mains were line honed... etc... it's a stacking of clearances