[Stan Weiss]

Originally Posted by PAUL K

These are great heads for a serious effort high performance Pontiac. They are copies of what we consider our "standard pushrod location race head". They differ from other commercially available CNC heads in many ways. But what we are most proud of (other than their power producing potential) is the lack of pushrod tubes and head bolt sleeves. For years I've rolled my eyes looking at ported heads that slice away the head bolt boss. The loss of integrity of the casting and potential for sucking oil far out weighs any power gain found from removing the head bolt boss. The pushrod tubes are almost always in the way of the pushrod or a shop installs a tube that is excessively large and reduces the CSA area at a critical point. These heads have made over 800 horsepower on stock block builds and have run 5.0 in the 1/8 on a 3300 lbs. street driven nitrous car.

The port volume is close to 250 cc.

Port window has been optimized to work with a Victor manifold.

That's a modified cast 72 CC chamber in the picture. We have done these heads with the Edelbrock CNC chamber and 87 CC ports. Valve size can be varied per application.

Delivery times are a mess due to parts availability, folks not wanting to work and the people that are willing to work being over loaded.

Paul,
What bore size was used for the numbers Brian posted?

Stan

[PAUL K]

Originally Posted by Stan Weiss

Paul,
What bore size was used for the numbers Brian posted?

Stan

Hi Stan, 4.25

[Stan Weiss]

Originally Posted by PAUL K

Hi Stan, 4.25

Paul,
Thanks. I know even shops that do a lot of head porting still have a limited number of bore sizes. With that bore size I would guess they will lose very little or nothing flow wise on a 455 +30 or +60.

Stan

[Steve C.]

head flow vs. bore size

https://www.yellowbullet.com/threads...e-size.615123/



.

[PAUL K]

Originally Posted by Stan Weiss

Paul,
Thanks. I know even shops that do a lot of head porting still have a limited number of bore sizes. With that bore size I would guess they will lose very little or nothing flow wise on a 455 +30 or +60.

Stan

Very little Stan. If we set everything up there is almost no flow loss with a 2.11 valve on a 4.185 bore.

[blueghoast]

Originally Posted by PAUL K

Very little Stan. If we set everything up there is almost no flow loss with a 2.11 valve on a 4.185 bore.

Can you do this with a Speedmaster head also and maybe a 2.19 valve
I've got a set of bare heads is why I'm asking.

GT

[PAUL K]

Originally Posted by blueghoast

Can you do this with a Speedmaster head also and maybe a 2.19 valve
I've got a set of bare heads is why I'm asking.

GT

Possibly, we are going to look into that as soon as we get our heads (the other heads) above water. Valve size is not an issue.