I have on my stand a bored and honed 4.155" bore block.
I trial assembled, the 1-3-5-7 bank measured between .026" to .028" deck clearance, the 2-8 bank measured .022" to .024". Obviously the deck is not square, and there could be slight variations in rod length.

The pistons have 5cc valve reliefs. (SRP 416 gram flat tops)
The heads used are 70cc chamber Performer RPM's
I will be using a Fel-Pro gasket with .039" compressed thickness, and an advertised compression volume of 8.9cc's.

What CR would I end up with having the deck squared at .022, and what would I need to have decked to arrive at 10.0:1?

Eric

 

http://www.race-cars.net/calculators...alculator.html

 

Eric: I get 10.38:1 using your info.

To get 10:1 compression I would select a .041" thick gasket (9.1cc) and deck to .022" and remove 3 or 4 cc's out of each combustion chamber. ( enlargen the chamber to 73-74cc's)

removing 3 to 4 cc's from each combustion chamber is no big deal. Lots of meat there
on a aluminum head. I'd cc the heads first to verify they are infact 70cc's. and go from there.

Pete's performance calc page

 

I do plan on having the heads CC'd as well as having them check to see the steam holes put in them are correct- I bought the heads used so it's a good idea.

I am so glad I did not go to the first machine shop I talked to about getting the work done. They insisted I didn't need to mock it up, and that they could measure from the centerline of the crank and zero deck it. Yeah, I'd be sky high on CR if I listened to them.

The only prob I see with taking meat out of the chambers is I'd really have to buy my own stuff to CC them, or else I'd be grinding some, taking them back to be checked, and so on.

10.3:1 wouldn't be a huge issue, I guess it depends on who you talk to, some say 9.5:1 on iron heads is the max for 93 octane pump fuel, and go up a full point to 10.5:1 with aluminum heads.
I would rather keep it on the milder side between the two.

Now would my quench clearance be the total of the compressed gasket thickness used plus the .022 my pistons will be in the hole?

 

Yes