Speedmaster Small block porting tips and results Part 1
I thought that these SM heads were a copy of the Eddies?? So, would the regular, unported SM heads flow about the same as a OOTB Eddy?? ?? ? Flow numbers on the web says so…..
First, let me say it’s important to keep in mind that flow numbers that come from different benches shouldn’t be looked as data that can be compared “apples to apples”.
It can’t.
Even if the benches themselves were very close to each other, each shop is using their own radius air entry, bore adapter, etc.
All of these things, including the differences in the numbers produced by the bench itself are why it’s not “apples to apples”.
I say that as a preface to this......
On my bench, with my bore adapter and my radius air entry, an ootb RPM has better numbers than an ootb SM head....... in the lift range where most people are going to be running ootb heads(under .550 lift).
Pretty much all of that difference is in the valve job.
From a flow perspective, the Ede valve job is better.
Take an assembled SM head, recut the seats, back cut the valves, do some very minor blending....... it would probably equal/outflow the Ede Head from top to bottom.
I had to dig pretty far back in my notes.
There can be a noticeable spread between the 4 ports on these heads. I usually test the #1 cylinder.
It’s been a while since I flowed an ootb E head(60779).....
4.00 bore, no tube on ex:
Lift———in/ex
.100—— 64/49
.200——126/97
.300——185/133
.400——227/156
.500——250/166
