Angle milling

[Steve.k]

I recently picked up a set of either Gliddens heads or roush 4v cleveland prostock heads. Youcan see the heads angle milled was that to get straighter shot into cylinder?

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Notice valve cover rail.or was this primarily to cut chamber smaller because of valve angle ?

[ProPower engines]

Most likely the intake face was machined to match up the intake manifold.
Regardless after the heads are machined either flat or angled the intake face needs correction more so then the intake to
get things lined up again. Since they may have been testing intakes its easier to machine the intake gasket face
then the manifolds so they can be shelved for other projects without making them orphans.

But its not done to reduce the chamber size. Or the port CC's for that mater.

[dannobee]

What does the chamber side look like? Were the dowel pins offset, shifting the head higher on the block? Just curious what the exhaust ports look like, too.

[ProPower engines]

The exhaust port side has a flange bolts to it from the valve spring side of the V/cover rail.
They did that to improve the port flow and mount better header flanges to the head.
They a lot of times did that with aluminum for ease of machining and weight reduction on the front end of the car.
Seen that done with steel as well for street stuff.

[superpursuit]

Looks like it has been high ported on the exhaust side.

Those vanes bolted in the inlet ports are interesting. Does anyone know the reasoning behind that?

Allan.

[engineguyBill]

Allan,
My guess is that they were trying to enhance the swirl of the intake charge, but it seems like those vanes would really restrict the airflow.

[superpursuit]

Thanks Bill,
I thought it was something along those lines but at the revs those guys were pulling the angle seemed too much. Interesting how they have done each one differently for each inlet port. Got to wonder if they developed them that way or if it was just guesswork.

Allan.

[Steve.k]

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. Here is combustion chamber. I have another set from p/s racer from Florida.He used epoxy to try and turn flow to center. That vane turn it opposite direction.

[Ken_Parkman]

I ran across intake vanes like that on a set of Olds heads. I concluded they were "vortex generators" to create a SSR vortex to improve flow attachment as it makes the bend. You can see the concept in various aerodynamic aircraft applications; an interesting one is on the B727 center engine inlet duct. Aerodynamically the concept is sound, and when I flowed the Olds heads with and without it was clear the vanes kept the flow much better attached around the SSR and the flow was notably improved. However the flow was extremely unstable. The vanes clearly reduced the separation - called stall by most, but really not the right term.

However - no Idea what happens in a running engine. Just seems wrong to me - wonder if anyone has actual engine or track results?

[Kenny M]

Looks like it has been high ported on the exhaust side.

Those vanes bolted in the inlet ports are interesting. Does anyone know the reasoning behind that?



I worked for Roush back in the day, Edgar was are head guy. I believe this was to help stable the turbulence and air separation. These 4V heads can flow 350, but to make them happy they need the back of the bowl, behind the guide and the lower common wall filled.

[Steve.k]

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. Heres exh side. I'll get. Closeup later.

[Steve.k]

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Heres some pics of another set i have. You can see epoxy to turn flow. Lots of work on these ol heads.