GURNEY VALVE COVERS FOR 302 AVAILABLE?
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Marco is right, if you were able to put a set of Gurney heads side by side with a 'conventional' set, you would be, perhaps , surprised by the differences. The Gurney head itself is higher, and consequently the valve cover is about half the height of standard, and attachment is also not the same. The Gurney head has a rocker shaft, and the intake ports are a straight shot, vertically, to the valve. As a consequence, the Gurney 4 barrel intake is a tortured piece, where each intake runner has to make a right angle downward turn to get to the cylinder. These heads were really meant for the weber intakes where the carb is atop the cylinder and the intake charge goes straight to the combustion chamber. To bring the Gurneys to 2002 standards, the intake port needs, if it has ever been ported, to be made smaller to get some increased velocity, and the tulip style valves need to be done away with, as flow is improved with the 'valve on a stick' type. Together, the modifications will get you to 300 cfm at .600 valve lift. Above .600, the rocker stands need to be shimmed, and unless you need every last ounce, don't go there. At 300 cfm, the head is competitive with most aftermarket. Many times the aftermarket heads that get 300+ cfm do it at .700 or so at the valve. The Gurney heads can also accept 2.19 and 1.73 valves. Generally the quality of the castings is very good. If you remember their advertisements from the late 60's and early 70's, it was advertised to add 70 plus horsepower with the head change, using the 4 barrel intake. Most of the chambers, incidentally, were 63 cc, same or close to ford at the time. With the rockershaft design, they also tolerate high rpms quite well. So keep looking at the swap meets and classifieds, you never know when and where a set will turn up.
Roger D.
Roger D.
Correction, make that 1.71 on the exhaust valve size. These vintage heads may not be 'cutting edge' by any means, but they look really cool and have a great exhaust note to boot. Too bad none of us stocked up on them about 15 years ago or so, they sure would have been better in the IRA than lots of other things. For that matter, an entire original GT40 would have been better yet.
Hello, !
Issue is the MkIV heads...
Valves are different angled than on stock heads.
Standard valves: 2.1/32" intake
1.5/8" exhaust
Intake standard ports : 1.9 "
Exhaust ports: About 1.7 "
In -66/-67 with a hybrid injection system a 289 was producing 506 HP at 7800 RPM on straight gasoline !....
later 305 engine responded with an extra 14 BHP at same RPM´s.
The heads are still modern due to Mr Weslakes geniality.
Incorporates nearly straight intake and exhaust ports.
Flows a massive amount of fuel/air mixture.
Standard chambers: 52 cc.
And is traditional and well proven Weslake design with easy breathing and excellent flame propagation.
Valve angle is 9¤ instead of the stock 20¤.
Allows for greater lift.
With a Mustang II 1979, Gurney got 258 BHP at 5500 out of the box on a standard 150 HP 302.with the Holley 600.
After installing a 3/4" grind cam they pulled 300 BPH.
With full race cam and a quartet of webers they pulled 376 BHP with idle at 800 RPM.
With same standard 150 HP 302 as basis.
Of course development has gone further today.
But i doubt aftermarket stuff today are any improvment in design.
Running Weber´s also got pretty straight porting wich can not be found on aftermarket heads, as far as i know...
Castings are much better today, with much better aluminium mixtures as well.
As we all know, stainless and aluminium etc.. are mixtures of very different types depending on what you are to use it for.
Alloy´s really, since the pure metal´s are´nt any "good"
Round ports and this facts are for the Gurney/Weslake "standard" outfit !....
They can alway´s be tuned further...
And what a history; Indy, Sportscars, one off´s highly tuned racers and drag strip.
Guy´s from O´Connor Lincoln-Mercury destroyed
the NHRA D/Gas record with their Eagle-Cougar
running 126.31 mph in 11.11.
After record was set this 302" Cougar ran consistent high 10-second ets.
Etc...
To prove streetability of the 4 barrel conversion.
Gurney converted a Stock 302" -68 Cougar with auto trans and a 3.50:1 gearing using an off the shelf package.
Ideled smoothly, offered better than average fuel economy and ran the quarter-mile at a shade over 100 MPH in the high 13s.
This streetable and reliable machine boasted a top end in the area of 130 MPH !
The covers are about 1.7/8" high.
And about 1.2/8" in hight internally !
NOT TO MENTION THE INDY cars and the GT40 !
Issue is the MkIV heads...
Valves are different angled than on stock heads.
Standard valves: 2.1/32" intake
1.5/8" exhaust
Intake standard ports : 1.9 "
Exhaust ports: About 1.7 "
In -66/-67 with a hybrid injection system a 289 was producing 506 HP at 7800 RPM on straight gasoline !....
later 305 engine responded with an extra 14 BHP at same RPM´s.
The heads are still modern due to Mr Weslakes geniality.
Incorporates nearly straight intake and exhaust ports.
Flows a massive amount of fuel/air mixture.
Standard chambers: 52 cc.
And is traditional and well proven Weslake design with easy breathing and excellent flame propagation.
Valve angle is 9¤ instead of the stock 20¤.
Allows for greater lift.
With a Mustang II 1979, Gurney got 258 BHP at 5500 out of the box on a standard 150 HP 302.with the Holley 600.
After installing a 3/4" grind cam they pulled 300 BPH.
With full race cam and a quartet of webers they pulled 376 BHP with idle at 800 RPM.
With same standard 150 HP 302 as basis.
Of course development has gone further today.
But i doubt aftermarket stuff today are any improvment in design.
Running Weber´s also got pretty straight porting wich can not be found on aftermarket heads, as far as i know...
Castings are much better today, with much better aluminium mixtures as well.
As we all know, stainless and aluminium etc.. are mixtures of very different types depending on what you are to use it for.
Alloy´s really, since the pure metal´s are´nt any "good"
Round ports and this facts are for the Gurney/Weslake "standard" outfit !....
They can alway´s be tuned further...
And what a history; Indy, Sportscars, one off´s highly tuned racers and drag strip.
Guy´s from O´Connor Lincoln-Mercury destroyed
the NHRA D/Gas record with their Eagle-Cougar
running 126.31 mph in 11.11.
After record was set this 302" Cougar ran consistent high 10-second ets.
Etc...
To prove streetability of the 4 barrel conversion.
Gurney converted a Stock 302" -68 Cougar with auto trans and a 3.50:1 gearing using an off the shelf package.
Ideled smoothly, offered better than average fuel economy and ran the quarter-mile at a shade over 100 MPH in the high 13s.
This streetable and reliable machine boasted a top end in the area of 130 MPH !
The covers are about 1.7/8" high.
And about 1.2/8" in hight internally !
NOT TO MENTION THE INDY cars and the GT40 !
Marco, the set I currently own were ported circa 1970 by Mondello Porting, who like most porters of the era had never heard of a flow bench. When in doubt, bigger was better, and velocity suffered as well as both torque and horsepower on the lower end of the rpm range. You're correct that if someone has never seen the Gurney heads, it's a 'jaw dropper' to look straight down thw intake port to the valve. The exhaust port has a good angle also. There are very few "line of sight" cylinder heads like the GW's. Remember over the past 2-3 years that the big scramble in both Chevy and Ford competition cylinder head design is to get less valve angle, as Ford did, for example on the N351 cirrcle track heads. The Gurney's were a few years ahead of their time. For the heck of it, I'll have my head guy take some digital pix of the heads, describe what modifications he made and why (bear in mind that some are modifications of prior modifications...) and give some flow data from his computerized bench. It will probably take a while for me to corral this from him, so I'll get started.
Roger
Roger
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