Gurney Weslake Head performance

Now these are rare. Lets just say I know where all of them are both finished and semi machined. And these are not the rarest items I got from Dan.

And on another thought I do not begin to understand why AFR heads are somtimes brought up when talking about air flow numbers as there are trailer truck loads of 25 year old NASCAR heads that can flow so mch more for less money. Some people seem to think 400 HP is a big number and a freshened 15 year old NASCAR engine can make double that for 15K on a single 4v and good pump gas.



New Member
Hey guys thanks for the Gurney/Westlake Ford head pics. I understand Dan Gurney approached Ford to market the "head package", but Ford at the time was ridin' too high and missed the opportunity. If Ford had taken on the Gurney/Westlake head project, the small block Chevy would have been relegated to a quiet passenger car history. Oh well, now it is Ford's turn. For 2013, the Shelby Mustang is equipped with a 650 HP FOUR valve, DOHC 5.8 liter V-8. Ford points out they have the most powerful production car engine!!! Try topping that Government Motors...
Hi, an interesting note is Gurney and Weslake did make multi 3-4 valve pushrod heads for the sbf+sbc engines that made some very good power #'s.

I have heard but not been able to confirm Weslake did make a test 4v sbf pushrod version baised off there sbc design also. Many dont know it but the 32 valve Dominion and Arao version heads are modeled after the old weslake design, just with there own take on using stock type int and exh setups.
Did the engine in picture 5 have a name/designation. I know it appears to be a 3 valve per cylinder pushrod engine with reverse flow heads. Any ideas where there is more info on this engine and its vintage(I assume 1969-71)? Just curious as it appears to be an interesting variant.

Jac Mac

Active Member
Pic #5 is the 3 valve as tested by Gurney in race car, center exhaust/outer inlets was how they were built, mid 1969 saw the first heads finished.
Running pump gas & those slide injectors @ 344 cubic inch ( 4.110 bore x 3.25" stroke) made 606hp @ 8500 RPM, I am not aware if they were ever built in passenger car configuration with intake in center as that would require a major rethink.

Just goes to show there is nothing new in the world, the 3.250" stroke & big bore combo was in vogue back then, took the aftermart nearly 25 years to wake up..

The bore centers of the SBC & SBF are so close at 4.380" vs 4.400" that its not surprising that they both were candidates for the 4v head swaps... Bob Jane in OZ funded the conversion of his SBC Chev Monza Trans Am car to have Boss 302 heads adapted back in the 70's.
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Comparing current technology to technology from the 60's in regards to cylinder head design should not really show any large advancement, except in manufacturing. I think the big leap is in that part of development. Even the most advanced cylinder heads today are not doing anything that was not available since the 20's. The only advancement would be in the variable cam timing, but, that is not really head design. Big change in engine power now comes from electronics.

I recently read that Jon Kasse is developing a Windsor canted valve head that is giving good horsepower numbers. Head is called P-38. Flow numbers from his website look quite remarkable. The head supports stock intake and exhaust patterns. They do not require special manifolds.

"Equippedwith Kaase P-38 cylinder heads, a modest camshaft, and an Edelbrock Junior intake, the 302, running on pump fuel and barely 9:1 compression ratio, easily generates 500hp @ 7500rpm."

Numbers taken from his website:

P-38 Cylinder Head Specifications:
Chamber CNC machined: 60 cc
*Intake Runner Volume:*
240 cc
Exhaust Runner Volume:
86 cc
Intake Valve Diameter:
Exhaust Valve Diameter:
Intake Valve Length:
Exhaust Valve Length:
Intake Valve Angle:
Intake Valve Cant.:
Exhaust Valve Angle:
Exhaust Valve Cant.: 4
Valve Spring Diameter:
Valve Guide:
* Intake runner Volume CC can not be compared to other Windsor cylinder heads because of deeper valve bowl area. * Valve Spring Installed height up to 2.000

Flow Chart as Delivered @ 28'' Superflow SF-1020 Pro Bench

156 cfm

219 cfm

.400 265 cfm

297 cfm

308 cfm

309 cfm

311 cfm

Exhaust .200
111 cfm

142 cfm

169 cfm

185 cfm

199 cfm

208 cfm

215 cfm

Flow Chart with Conventional port work @ 28'' Superflow SF-1020 Pro Bench
(not a raised port)

163 cfm

232 cfm

.400 285 cfm

328 cfm

348 cfm

350 cfm

355 cfm

110 cfm

153 cfm

194 cfm

222 cfm

233 cfm

238 cfm

241 cfm

Jon Kasse's website is Jon Kaase Racing Engines - Kaase P-38 Canted Valve Small Block Ford Heads

Jac Mac

Active Member
I helped a local gt40 member obtain a set of these a few years ago, but it will be a while before they see action yet I think.

What I would like to see someone do is take the Yates valve, chamber, port configuration & transplant it into the windsor envelope... It can be done by increasing the depth of the windsor head ( from block face to rocker cover rail- widening from original intake face toward the valley ). The Yates intake port area is very similar to the larger Victor type inlet manifolds for windsors etc so with some simple alloy end gap spacers these intakes could be used, the exh would still be windsor style using the yates dimensions to the point where it meets the windsor port face. Because the Yates uses closer valve angles a set of dedicated rocker covers might be reqd, but really thats the major parts reqd. Then you would have Nascar power potential in any windsor configuration.
Sooo, whats needed:
Hardware for a pair of Yates heads- valves- springs-rockers- rocker covers.
Pushrods to suit- rev kit if reqd.
Front & rear valley spacers.
Windsor manifold of choice to match block being used- 8.200,8.700,9.200,9.500.
Two very special windsor heads!
Someone clever enough to assemble it.