Cylinder Head Question

[Pat Powers]

Can someone please explain, why per the rules for this class that a Canted Valve Head for a SBC is not allowed ? Are there such great advantages to these heads that they are not allowed ?

Any info to clarify the reasoning behind this would be greatly appreciated.

Pat

[TRW427SS]

Can someone please explain, why per the rules for this class that a Canted Valve Head for a SBC is not allowed ? Are there such great advantages to these heads that they are not allowed ?

Any info to clarify the reasoning behind this would be greatly appreciated.

Pat

Because a SBC never came from the factory with a Canted Valve Head only In-line Valve Heads......

[Pat Powers]

Thanks for the reply, but your statement is not completely true.

In the 60' Chevrolet developed the Porcupine Head (Canted Valve) which was used by Smokey Yunik. Very few went into production, and even fewer found their way onto production cars. But they are out there.

So, the SBC was not only available with an inline valvetrain at one time.

Can somebody else provide any information as to why the Cylinder Head is not allowed ?

Thanks

Pat

[Robin]

Thanks for the reply, but your statement is not completely true.

In the 60' Chevrolet developed the Porcupine Head (Canted Valve) which was used by Smokey Yunik. Very few went into production, and even fewer found their way onto production cars. But they are out there.

So, the SBC was not only available with an inline valvetrain at one time.

Can somebody else provide any information as to why the Cylinder Head is not allowed ?

Thanks

Pat


That was the predecessor to the big block. The "mystery motor". The big block has had canted valves from that original design. The small block never came with canted valves in a production vehicle.
In NPS only the Fords are allowed a canted valve head since they came with them from the factory at one time. The rules should either hit the Fords or allow a SBC to run canted valve heads:mad:

Robin

[PRO_Voice]

And I still don't understand why cast iron, 1964 vintage 426 Hemi heads aren't allowed in the class, either.


(stirring the pot!)

[Pat Powers]

That was the predecessor to the big block. The "mystery motor". The big block has had canted valves from that original design. The small block never came with canted valves in a production vehicle.
In NPS only the Fords are allowed a canted valve head since they came with them from the factory at one time. The rules should either hit the Fords or allow a SBC to run canted valve heads:mad:

Robin

Actually there was a very limited amount of Corvette's that came with them in late 62' early 63'. Does that still not make them production ?

Pat

[David Beeson Jr]

I have a friend interested in running NPS and wants to run a sbc combo with the canted valve design. He said those heads came in chevy pickups and are still commercially available heads. Here is the GM part # 24502517 available in 2006 GM performance parts catalog. Can anyone explain why they won't allow these heads?

[Robin]

I have a friend interested in running NPS and wants to run a sbc combo with the canted valve design. He said those heads came in chevy pickups and are still commercially available heads. Here is the GM part # 24502517 available in 2006 GM performance parts catalog. Can anyone explain why they won't allow these heads?


:D:D:D:D:D

Let me know if that happens along with the Corvette deal in the sixties;)

Robin

[Pat Powers]

Robin,

I really didn't come on here to stir the pot, I was just looking for an explanation. But since you bring production into the mix. The rules allow a 4.900 bore space for Natually Aspirated Motors ? How is that production ? What about a spread intake port on a Big Block ? Was that ever production ?

Pat

[Robin]

Pat, If you want to ask I have no problem with that. I am not the rule guy so I am sorry if I came off sounding like that.

Don't ever make the mistake of using logic as it applies to the rules. You will end up like Scott Sparrow...:D

I agree with you on your point about heads. I wanted to try a ET Canted Valve head but was informed that an LS engine was never produced with that head combination. I remember hearing the Ford guys ask for their Yates style head to be allowed in NPS. They said that the LS engine had 12 degrees with some of their production pieces.

I am suprised that they are not a lot faster based on what we have seen from our inline head small block combination. With our C5R heads we are close to 400 CFM at .750 lift. It's clean past 1" but doesn't flow any better at the higher lifts. The heads that are allowed on the SBF are 50 to 60 numbers better than what we are allowed to run.

Right now it looks like the SBF with a Yates or blue thunder is the hot ticket:mad:

Robin

[Pat Powers]

Robin,

Thanks for all your input. Hopefully someone will have a true answer as to why they are not allowed or atleast weight penalized ?

Pat

[GTMADNS]

Robin,
I true yates head(c3, c3l, sc1, d3) is not legal nor is the BT 4.3 head becuase of valve angles. The bt 3.6 is and the brodix neal head and most inline heads. Im still asking how a bbf head is legal? The ones that are on a certain racers car (bbf) are below the minimum valve angle(per rules not legal). what gives there? bbf are excluded from the valve angle rules?

[David Beeson Jr]

Sorry about not responding, have been without power,phone,everything because of Gustav, but I now know of more current GM catolog book with heads I spoke about earlier, but I will have to get back with info as soon as I can.