Hey all,
No, "head milling" is not intended to convey the feeling caused by consumption
of too much Bass Ale. Here's the deal:
As some of you know, I'm in the middle of rebuilding my GT6 engine. The car
had been producing very little power (I mean, less than usual). After
disassembly we took some measurements to see what was what. It appears that
my particular DPO (I like to call him Rudy), replaced the head at some point,
not with a GT6 head, but with a TR6 head. (I'm gonna get you Rudy) I
understand that the GT6 (plus and Mk. 3) shares the head casting with the
TR250/6 cars in their various forms, the difference being the thickness to
which the casting was milled.
SO, long story short, I've got a head which is considerably thicker than it
should be (3.540 in. as opposed to 3.320 in.), with a combustion chamber depth
of .680 instead of .470 in. With this head, compression ratio is 6.2:1
instead of 9.25:1. This, I think, is bad.
Originally, the plan was to take .085 in. off the head to get to a combustion
chamber depth of .385, zero-deck the block and get a 10.75:1 compression
ratio. However, doing the math, it appears that I will have to have .295 in.
milled off of the head to get to .385 combustion chamber depth.
AT LAST HE GETS TO THE POINT. Can this much be taken off of the head? If I
understand correctly that the castings are the same, it would appear that this
much was taken off of the head in manufacturing to make the casting into a GT6
head as opposed to a TR6 head. So it should be fine, right?
Scott
Scott Barr8@aol.com
72 GT6
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