View Single Post
Old 30th April 2006, 05:58 PM  
Join Date: Oct 2002
Location: Canada
GT40: Project
Posts: 38
Re: Gurney Weslake Head performance


After some surfing around the Net, I found this on the GW heads. Sounds like a completely stock, unported pair of heads.

Just in case you're interested.


The heads tested belonged to a friend and when we pulled the valves out,
it was apparent these heads were not going to live up to their potential.
It's not because of anything wrong in the basic design but rather they
didn't appear to have been finish-machined. There's a huge step at the
short side radius that's sharp enough to cut your finger on. Bob said
blending that area in would be worth a bunch of CFM and power. He guessed
the intakes wouldn't flow over 225 CFM but that, with some work, they
would pick up to 300+ CFM. The flow bench tells the tale. Same set up
as before (28" H20 pressure drop, clayed inlet radius, no pipe on the

Valve Gurney-Weslake SBF
Lift aluminum heads
(inch) Intake Exhaust
2.02" 1.60"

0.025 23 35
0.050 35 45
0.100 67 64
0.150 102 80
0.200 133 93
0.250 160 104
0.300 179 113
0.400 202 134
0.500 202 145
0.600 --- ---
1074R/001 is offline   Reply With Quote