Bill-
Regarding your GT6 compression ratio...
Unfortunately I can not tell you the measurement you need to get
9.25, but I can tell you that to achieve 9.50 ratio, your head
thickness should be 3.330". While you are doing this, it may be
the time to just touch up those raised areas on both sides of the
combustion chamber (at least take off the edges). If you do
indeed clean these up, it will decrease your comp ratio slightly
and be nearer your desired ratio.
The other way to measure that head is to measure from the mating face of
the head to the combustion chamber floor. This measurement should be .425" to
obtain a compression ratio
of 9.25. If you need to go further into this, I believe the formula
v1+v2
-------- = Compression Ratio
v2
where v1= Total volume of cyl
v2= Vol above piston at TDC
and if memory serves me correctly, the volume of the head gasket
is about 4 cc's and the vol above the piston is about 6.3cc's.
This of course assumes a stock bore and stock gasket.
The Car Curmudgeon
Nick
|