Porting SC Heads

[1972_911T]

Is it worth the hassel to port small port SC heads or is it more cost effective to buy a set of early large port heads?

What would a typical machine shop charge for this?

Steve

[EarlySport]

I've wondered the same. I don't think it's particularly difficult to open up small port heads to a larger port size, and you could certainly raise the ports if you ported out a small port manifold as well.

That said, I've just gone and bought a set of 3.2 heads for my rebuild, and will play with the small port SC heads when I have more time..

[cstreit]

It ended up being close to the same cost when I've done it... With the added advantage of having the ports "cleaned up" around the valve guides and seats... I'd port 'em

[jluetjen]

The first -- not-so-obvious answer is: why? Are you going to be changing the cam spec or capacity of your SC motor? Or are you expecting to gain some HP just by porting the heads? Keep in mind that I believe Porsche quoted the same HP for both versions of the SC -- small and large ports. So unless you're going to change other stuff -- like cams and CR, it's not clear to me that it would be worth the trouble in and of itself.

[1972_911T]

Yes the engine is been rebuilt as a 3.0 MFI Engine probably with S or Mod S cams.

Regards Steve