MEASURING HEAD
VOLUME IN CC's
OK, yea ask why. Why? I'll tell ya why.....
Yea see, measuring and calculating cylinder
head volume in cubic centimeter (cc) is important
not only for determining compression ratio, but
also for determining the limits of decking (shaving) your
head to eliminate head warpage, or to simply figure
how close your piston comes to the valves at top
dead center. If you ever plan to install a new
custom piston, you should be positive of ALL
piston to head clearances.
This procedure is also used by top machinist to assist
motor builders in pushing the limits.
So, here's a summary (quick outline) of the procedure
to figure/calculate Head CC's.
With your head removed from your motor,
valves freshly lapped into the valve seats (aka valve job),
flip the head on the work-bench with the bottom of
the head facing up. A fresh valve job will help contain
the water in the chambers dome while measuring.
Make sure the head is level on the work-bench.
An un-level head on the workbench causes the
water to collect to one side of the dome-and we
don't want that. Apply a thin layer of bearing grease
(light blue in pic) around the diameter of the head dome.
One more thing, keep the old spark plug installed
in the head..... :)
Here's a picture to help illustrate...