Geoffrey

I'm looking for a set of core unmodified cylinder heads for a project. These can be complete heads or just bare heads. They can be early or late style.

Thanks in advance.

jim dorociak

I have a set of 95 993 heads complete with valves/springs. - Jim

Jim Howley

You creating another masterpiece Geoffrey?

Geoffrey

I appreciate the offer on the 993 heads, but I need a stock set of 964 heads for a stock racing class engine.

9sixty4

What is the difference between the 993 and 964 heads? Could I use one 993 head on a 964 engine?

Geoffrey

The 993 cylinder head has exhaust stud holes at all 4 corners of the port where the 964 exhaust studs are only on 2 opposite sides. The 993 mounts 180 degrees from the 964. You can put a 993 head on a 964 by moving the studs, but you cannot put a 964 head on the 993 without using a 964 flanged exhaust.

The 993 uses 8mm valve stems, the 964 uses 9mm. The 993 uses slightly larger intake and exhaust valves depending on RS 51.5/43.5 or 96-later Varioram 50/43.5 or 95 non varioram 49/42.5. 964 is same as 95 993

The 96 and later 993 heads are made from RR350 alloy which is the same as the 3.3 turbo head alloy, the 964 uses the same as 3.2 Carrera and not as heat resistant.

As Colin has shown, and I agree, the port size of the 964 41.5/38 is better matched than the larger 993 intake port size 43/39.

So, yes you can and the 95 head would be the better head in my opinion than the 96-later head.

The intake port size is 43mm on the 993 and 41mm on 964

9sixty4

Thanks Geoffrey, I have one trashed late (1992) 964 head and need a replacement. I found a 993 head but I don't think it would be wise to use one 993 on an engine with 5 964 heads from what I see in your very informative post. Much thanks!

993944S2

Did you ask Joel. I think he has some 964 heads.

Don

NineMeister

I concur, you should not mix 964 and 993 heads on the same engine. I managed to find Geoffrey the replacement set for his Cup engine rebuild and also have a few more around and about, so if you cannot find a suitable replacement head stateside I have some nice ones from a 40k miles 1993 964 motor. I think I have five left, the price for a single unit would be £200 including valves, springs & retainers as lifted from the cam carrier.

Geoffrey

It is hard to find someone who is willing to break up a set of heads and sell you just one. I looked through my parts and all I have are cracked ones, or ones that have been ported. I wouldn't hesitate to get a stock one from Colin, the new ones are $1500 list price from Porsche. Kind of makes Colin's Billet heads look like a bargain.

Also, if you purchase a stock head that has been surfaced, then all of your heads need to be surfaced to the same height. Make sure whatever head you are looking at has not gone below the wear limit. You can cut the head .020" according to Porsche specifications. Personally, I don't like to see them cut below .015" because it begins to make the cam seal not seal on the cam box since the engine is now effectively "less wide" than it was previously.

9sixty4

Joel? Don't know him.

9sixty4

Thanks Geoffrey.

Thanks Colin, I'm going to follow up a couple of more stateside leads. If they don't pan out I'll drop you a note on the head.

993944S2

Hi Jim;

The Joel I was referring to was Joel Reiser. National PCA tech for 993, 964 cups etc and the owner of http://www.reiser-technik.com/ Goeffrey knows him well.

Don

9sixty4

Thanks Don, I'll contact Joel.

viperbob

Check with Dave White Racing in Tampa. Call and ask for Dave and tell him I told you to call. I was there yesterday, and he has a BUNCH of heads there. I am sure he has many complete sets of 964, as well as everything else...