Duke

Here's the view of a 968 head for an engine I'm building right now.
The 968 ports are larger (and the intake gasket too) than the S2 (and therefore also the S)




But your head could easily be port matched to match.

Paulyy

Maybe the 968 head would be a better platform to start off at. Could pick up more power using the varocam also..

rude944

Have complete 968 head for sale if interested, pm me.

333pg333

I've got a worked 968 head and block also. This 944S head was to get my current motor up and running on a 16v platform before I think about the other project motor. It was our intention to kinda do a 'bolt on' conversion as much as possible. Still don't think it sounds too hard or not worth doing.

Paulyy

I always forget about that engine.

I say go for it with the 16v head. If anything goes wrong with that one, you still can bolt the 8v back on.

333pg333

Well except we're looking at having to hone or bore the cylinders and also going up to 9:1 c/r so we won't be bolting the 8v head back on. :-)

Paulyy

Pick up some more RPMs too i assume? Custom cams for the 16v head?

333pg333

Yes, custom cams. Haven't seen too many results of worked 16v turbos. Most info available have run stock heads/cams and obtained very good results. We want more power and more rpms. Hopefully the head doesn't crack. Still curious about the context in which the non 968 heads failed though?

michaelmount123

The early S head is prone to cracking at a stud boss. Keep in mind, though, that Porsche addressed the issue in later heads, but didn't identify those that are "fixed". If you have one that's working, keep on using it! I agree with Chris that S2 heads can also crack, but it's relatively rare. Also, my experience has been they also crack at the stud boss. Don't shy away from them, though. The 968 head is a nice piece, but the big intake ports have to be accommodated, and the VarioCam may or may not be suitable - depending on cam profiles selected. VarioCam can be disabled, of course, or modified to use a S2 tensioner. Note the S2 cams have one more tooth on the cam sprockets vs. the 968. Therefore the 968 tensioner requires 968 cams, and the S2 tensioner requires S2 cams.

blown 944

Patrick, I have an S head that has been repaired. I can snap a pic next time at the shop I'd you want to see it.

Maybe you could have Paul do some reenforcement to yours..

333pg333

Thank Sid. If you wouldn't mind, I'd like to see how and where these repairs are that you describe. Thanks.

Michael, this particular S head is in the US and I'm Down here. We haven't taken possession of it yet. Our intention was that while we're in there we might try and do a 'bolt on' 16v conversion (relatively speaking) and this particular head that has been modified is sitting in a workshop gathering dust so to speak. All this talk of cracking heads isn't so encouraging. Do you by any chance have any pics of said cracks? We also run larger 14mm headstuds so I'm wondering if this head has been modified to accept these is it going to be even more prone to cracking. I will ask the questions. Does this cracking manifest itself when you're actually torquing the head on or during racing? Might have to re think this all....As for the cams, we were intending to change the cam drive system to run two larger pulleys at the front of the motor. Similar to Chris's one in the pic.

AlphaOmegaPower

Very very interested in the dual cam gear set up. Along with cost

333pg333

That picture isn't of my motor. It's one of Chris White's own car I believe.
Having said that, if we go 16v we will come up with something similar. Once that is done costs can be quoted. Pretty high end stuff for these cars. What do you have?

mikey_audiogeek

That extra tooth gives options for playing around with cam phasing. The 16v heads don't like too much cam advance. Running a 968 intake cam with an S2 exhaust cam gives just the right amount of retard.

Although I am sure some would say it's a bit TOO retarded...

333pg333

lol...

Being serious, what experience do you have with these heads Mike? Is that on an n/a car or forced induction?