I have a 37 21 stud that is a stock rebuild and cam lift aside, I am curious as to how much will the heads be able to be milled to bump the CR? Also, what kinda CR can you expect by doing this? Does anyone know if there is a chart for the early engines re this mod? Fire away fellas.... Rat
1. Gaskets on, heads snug, balls of modeling clay or aluminm foil on piston quench area and valves. Rotate. This will tell you available clearance and possibilities for simple milling. I assume here 1937 type heads, as earlier heads with totally different chambers could be used on '37 block... 2. Further milling beyond step one will require recutting dome in head and/or milling valve pockets. This is non-trivial because few shops have a flathead doming cutter...but recently Ol' Ron Posted a startlingly simple way to make a doming cutter. Turns out a master die-maker is not needed... For ROUGH estimations, real numbers require seious measuring tech, Canadian service bulletins post cc-compression numbers for a lot of 221 combinations.
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