D3 NASCAR head

[Steve.k]

Does anyone know what typical port volume on these heads are? 268cc ?

[swampbuggy]

Steve I would think that would be a little bit small but I could be wrong. Mark h.

[af2]

What are you comparing port volume to?

[Steve.k]

Bigger than 268 wow. Im not comparing to anything just it's seems like for the hp they running must need it.

[hoffman900]

Port volume is useless without knowing the centerline length.

[Stan Weiss]

Port volume is useless without knowing the centerline length.

X2

Stan

[Walter R. Malik]

Port volume is useless without knowing the centerline length.

X2

Stan

X3 ...

[blykins]

I wouldn't get hung up on port volume, it's not everything, and making horsepower isn't based on port volume alone. A small CHI 3V head with 240cc port volumes will support way over 800 hp.

It seems like guys always try to go too big. You're better off with a higher velocity, small volume port.

[Steve.k]

Well yes it may if you spin it hard enough. Mark at chi says they recommend the pro port head or kaase 400 for anything 800 and up. Those heads sitting at 258cc.

[blykins]

We have a CNC port for the 3V's that sit at 240cc port volume. You can't tell they've been touched by the size of the port at the gasket. They will support over 800 hp. Not talking about 9000 rpm either, 7000-7500 will do it.

On factory heads, filled ports usually work wonders. Lose port volume, pick up velocity, pick up flow numbers.

[swampbuggy]

Mr. Blykins.....240cc port volume, 800 plus H.P. at 7000-7500 RPM's . Would you mind stating the M.C.S.A. of that port, intake valve size and cubic inches of the engine. Mark H. Thanks.

[blykins]

2.250" intake valve size, 434 cubes, 4.155" x 4.000".

[Steve.k]

Mark says for anything over 800 use the pro port or kaase 400 (im thinking i should really listen to the guy who builds the product).He did say some Aussie builders have a program for the 225 head to get close. If its not the hi port you will struggle to hit 700. Im thinking your heads Brent started as these then you upped the valve size for more curtain area. The 240+ cc is a lot bigger than mine and the curtain area is bigger. That would obviously make for more hp on same cube motor.

[Steve.k]

Port volume is useless without knowing the centerline length.

X2

Stan

X3 ...

Do you want to elaborate on this? Do the nascar boys have specific length they use?How do they achieve their set lengths.Im thinking for the basically same size engines this would nearly be all the same would it not?

[Walter R. Malik]

X2

Stan

X3 ...

Do you want to elaborate on this? Do the nascar boys have specific length they use?How do they achieve their set lengths.Im thinking for the basically same size engines this would nearly be all the same would it not?

Cross-section, along with velocity, are the most useful measures.
Volume will change with the length of the port and the shape of the valve backside.