[Spike]

I hear SC heads have larger valve ports...

Does anyone know if SC heads will simply bolt onto a 3.2 cylinder?

[Trak Ratt]

As for fitting they will. Bigger ports, the early SCs had bigger than the later SC but not so sure about the Carrera. The SC heads will not have the needed fitting for the FI temperature sensor though.

[jpnovak]

There are a few issues. First, only the 78-9 SC heads have the 39mm intake ports. The 80-84 are 36 mm IIRC. Of course, what are you comparing it to? The 3.2 heads are even larger at 40mm on the intake.

the 3.2 cylinders are 95 mm and dimensionally the same as an SC. Many people use them since the 3.2 cylinders are Nikasil and were never available in Alusil which most SCs were built with. This makes a difference when changine pistons.

The issue is a difference between the head to cylinder gasket. SC heads have them, 3.2 heads do not. This does not present a problem with installation on the heads just prevents you from boring them out.

so... you can use the 3.2 cylinders on an SC. I would not use SC heads on a 3.2 since they will not flow as much air.

[Mackpipes]

Emery, good question. I've never heard of anyone doing this swap. I would tend to think they would not fit without machining. Would you use the cam towers from the 3.0 or the 3.2? Are they the same part?

[William Miller]

Dave, you may be able to resolve a head question that's been bugging me for a long time. My car (83 ROW SC) had the block swoped by the PO. When I rebuilt it I found it was a US 82 and had the smaller ports in the heads. Problem was that the intake runners were the larger diameter creating a restriction or step where the runner mated up with the head. My only resource at the time was Waynes engine book that indicated that the 81-83 ROW engine 930/10 had the smaller intake ports. Valve same size. It seemed so wrong that I enlarged the ports in the head to match my runners.

I wouldn't recommend anyone doing it themselves, but I did. I believe I used a 1-3/8" hole saw (Almost exactly the right size). I made a jig to drill it out. Then blended the
bottoms with the shape at the bottom near the valve stem.

Emory, why not just take the heads to a machine shop?
Since youre already in Kensington, Do you know about Jacks?
They did my valve guides and ground the seats.
Really good price and fairly quick. (Like a few days)

[Spike]

Thanks for the replies. Bill, I'll check out Jack's - I had not heard of them before.
Ted - not sure about cam towers, etc. - mainly gathering data to use
to figure out if there is value in swapping heads when I have mine out for a rebuild. If SC head ports are smaller than my Carrera ports then it won't make sense to swap, just rebuild, clean, and look at the cam choices and springs, etc.

[Mackpipes]

For a little over rev insurance, I went with Aasco race springs and Ti retainers. Won't prevent a mechanical over rev, but it'll raise you rev limit.

[Noah]

FWIW, there's an interesting thread on the Pelican engine rebuild forum about using 3-bearing versus 4-bearing cam housings:

http://forums.pelicanparts.com/showt...hreadid=241685

Good reading.