SOHC heads

[jayb]

Not straight from me, I am just trying to duplicate the flow performance of the existing heads I have.  However, the castings on these heads are thicker and could allow more porting than existing heads, which of course would allow for more flow.

[machoneman]

Say Jay, have you considered billet SOHC heads due to all the casting availability/volume requirement issues? Sure, the raw material would not be cheap,  lots of programming before even any machining would be required and water flow passages would need to be figured out but......

If no, is the biggest factor machining time?

[jayb]

I have indeed thought about that, Bob, but I think the only way to get the water jackets where I would want them would be to make the head in two pieces, and then bolt it together.  Probably an O-ring seal between the head halves.  I'm not sure I would trust something like that for the long haul, so a casting with an integrated water jacket sounds more robust to me...

[machoneman]

Thanks Jay. No need to reply to this one but here's what I was thinking....

Some years ago on the FE Forum were pics and some details on a billet straight valve  FE head that IIRC was made by a Cobra kit car supplier. Anyway, what I do remember is that they machined into the head deck (or maybe the topside) the water passages where they wanted them. Then, they added plates with an o-ring to cover said passages. 

On edit: Found a link to actually a canted valve FE head. Know you saw this one long ago.

http://www.network54.com/Forum/74182/message/1228607668

Sad that this apparently was a still-born project as it seems to have vanished!

[482supersnake]

At least one engine was built with those heads.

http://www.youtube.com/watch?v=OF6yJscOp58

[machoneman]

Yes and I'm pretty sure the bare heads were $10,000 a pair.

[Autoholic]

Would it make any sense to do a wet jacket chamber roof that uses the head gasket to provide the bottom enclosure? This is how many engines do a wet jacket for cooling of the cylinders in the block, the head gasket provides some of the cooling enclosure.

[67gt350]

Another question on oiling on the SOHC heads. On Barry's 526 build I see he has a braided line from the right head to the left where I am assuming the oil passage runs just like on the front. Just curious about this modification. I'm guessing it maybe balances the oil flow through out the heads?

[Barry_R]

That is exactly what that is - a balance line.  I have done it a couple times after noticing that one head was getting more oil than the other in a customer car.  Not sure why it was doing that - but providing a little extra flow to the one side seemed to even things out.  The line was pretty small - a -3 if I recall correctly.

[67gt350]

Thanks for the reply Barry. Good information to know.