Trying to calc the amount I need to take off the heads (66 425)to make up for the 3cc approx. I have taken from the bowls .
Dia. head chamber = 10.5 cm
depth of segment ( not part of chamber and to be excluded from cm sq. of circle.) = 1.6 cm

Area of circle = 81-67 sq cm
less area of segment(9.05 sq cm)
= 72.62 sq. cm
x .05 cm =3.6 cc

.05 cm = 0.13 inch ??

Anyone pleasemike

 

Typically about .006-.008in. off equals 1cc. IMO have .020 total taken off to get you where you want.

 

Result of your conversion:

• .05 centimeters is equal to 0.02 inches.

• Which is what cutlassefi said anyway....so, your math was right, but I think you had a decimal misplaced in your last step.

• sb

 

cutlass efi , 80 cutlass ,

THANKYOU .

The prospective engine builder (now ex prospective engine builder ! )said "and we can take a slice off there ". It`s not a bloody cake so I am off to talk to another --more expensive but with a good reputation --where I should have been for a start.

 

I talked to my machinist about milling Oldsmobile heads. He recommended not going more than .0030 of an inch. He wacked another set .0055 upon the customers request and the head warped shortly after installation. He said their wasn't enough material to insure a true deck surface. He did not tell me what letter heads had the problem and I'm sure there is differences. The other thing to be careful of when milling the heads is the need to mill the intake to match. This seriously decreases the resale value of the intake. You should not have to worry about the intake with milling the heads only .0020.

 

I think you may have a decimal in the wrong place there. .0030 is less than my machine shop takes just as a resurface. (.005 is what they take each pass) All the other info you gave is pretty good. 20 thousandth is written .020"

sb

 

TX GUYS,

0.020 it is .That will work out real good to regain the compression lost .

An aside -- How close does this bring the valves to a zero decked piston arrangement ??
mike

 

No clue, what are the cam specs?

 

k .gotcha. So, Iam going to give you personally some figures soon so that you can tell me what cam you are going to recommend and then grind for me .

Just the man to answer tx
mike