427 C.I S.B.Chev C/W B&M Mega Blower
I am new to this forum and would like to say 'hello' from the land down under.
If I could, I would also like to get some advice on the new engine I am about to install in my '32 Roadster - the last piece of a total rebuild. It is a 'Dart' block based 427 C.I S.B.Chev full of all sorts of good bits and pieces. Callies crank & rods, custom made Racetec pistons, a CompCams hydraulic roller cam, lifters and roller rocker kit, and a set of RHS alloy heads, all of which when worked out equals a compression ratio of 8.1:1. It was all balanced, blueprinted and pieced together in the U.S.A. and I am absolutely rapt with end result. I already have a B&M 420
(from memory) Megablower C/W 2 x 625 CFM carbies off my previous engine which I was going to use. The set up as it is, has '8mm pitch' pulleys with 69 teeth - top
and 52 teeth - bottom, which by my understanding is well 'underdriven'. I want to achieve a final compression ratio of around 11:1. Am I correct in assuming that to do this I would need around 5lbs of boost and if this right, is it simply a matter of 59 teeth - top and 62 teeth - bottom. I am reading the sort of charts most of guys would know backwards, and have always built my own engines, just never one that was supercharged. Thanks in advance