Brian Verbeek

Hello all,

I am having head work done and I would like to know what the diameter is of the 'dish' that needs to be machined into the head when switching over to the new cylinders that have the sealing ring.
Also, the older style slip-joint obviously centers the heads on the cylinders, but how is this centering accomplished on the new style? Am I right when I assume the heads will center on the four machined corners of the cylinders? I would be surpised if the heads are only kept in place by the studs.

If the heads center on the on the four corners of the cylinder, then the diameter of the 'dish', or step, that is to be machined into the head is critical.

Thanks for reading, any information/help on this would be greatly appreciated.

Brian

Brian Verbeek

Jon,

Yes, you are correct, however, in combination with new cylinders, 964 103 *** 22 if I am correct.

Brian

Kevin

Brian;

Although anything is possible, I would not remachine the bowl or dish. You would have to move the seats and valve up further into the head. Then you would have to shorten your valves. If you are going to use your old heads just machine the sealing surface of you head completely flat. Another words you would be removing the outer step. You have to remember that your cam housing square up your heads, also.

Jeff Curtis

Brian, please make sure that the machine shop you're using is familiar with this type of work/modification - as it is a fairly standard modification in the P-Car industry, it has been done for years on "hopped-up" turbo motors, SC's and the like.

There is a shop up there in Pennsylvania, forget the name, one of the guys owns a 911 Turbo rocket that he twin-plugged and all.

Damn! Wish I could remember the name of the shop...they also were quite familiar with the head gasket/crush ring update.

I believe Windward Performance referred me to them, about five years ago when I had a Supercharged SC motor.

My point, and my opinion is...you shouldn't have to come on here and ask for specs on this type of job...the machine shop I would choose for this type of work should already know the specs.

Just my two cents...don't mean to sound so blunt.

Brian Verbeek

Thanks Kevin and Jeff, I understand the need for the machinist to know what he's doing, or about to do. .. I am working on a 'special' project though, and I just need the data at this time so I can move ahead with things.

Kevin, I also understand the cam housing squaring up the heads, but looking at the head/cylinder joint, even the whole assembly could move a little front to back, and horizontally, if the heads are not located properly onto the cylinders.

I am using these parts in an application other than a 964.

Thanks,

Brian.

Kevin

Brian;

It doesn't matter, if things get squared to your cylinder block. If your liners are set and your deck to your block is square and not pounded out, everything will align. Once your liner are installed in there bores, you will have little adjustment and or play. You heads can move at a maximum of 1/16", it is within spec. Like I said just machine the heads flat and square. I've mentioned this before, the guys who do this in there sleep is Ollie's Machine (by the way they do most of Andials machine work). Good luck with you project.