935 TWIN PLUG HEADS IMSA champions John Fitzpatrick

[rally junky]

Im selling my 935 heads that came from John Fitzpatrick racing back in the IMSA days. My Dad bought them in the early 1980s from the team for a race engine that we built . Now its time for someone else to own a piece of racing history. Complete with Valves and Springs, the will need a rebuild before you can put them back to use or you can set them on your desk. I have a set of 97mm Pistons and cylinders that go with them and its set up with Nirosist rings for holding in the boost. ASKING $10,000 obo

[VZ935]

I have a lot of those 935 heads and have sold a bunch to help fellow racers so I have some insight into the prices if your interested. GLWS

[rally junky]

Thanks that would be great to know what the market is on these heads today. I have seen a set on Ebay sell for $10,000 with out valves and springs. Let me know if you know anyone that needs a set.

[Ollies930]

Very interesting that the factory racing heads are not RR350 material. Or are the racing heads RR350, but simply do not have the logo cast into them?

[Craig 930 RS]

My 930 uses early SC heads, twin plugged and Ni-resist ringed........gets the job more than done

[Ollies930]

I am not saying that the standard casting material will not work, but if the factory decided to cast 935 heads in the regular alloy(if that is what it really is), I would love to know why. The racing department would not do anything without a good reason.

[Ken911]

I was wondering the same thing. They did change the alloy for the 3.6 turbos, it might be that.

[Ollies930]

How weird, I was not aware that the 3.6's used a different alloy again. But the RR350 was used specifically on the 930s due to the higher temps from what I understand, so curious why not on 935s? But interestingly enough, I have seen 993 RSR normally aspirated heads with the RR350 logo on them. Go figure.

[Ken911]

Yeah when I took my heads to xtreem to have them twin plugged and ported. He had a bunch of the singer engine heads he was manufacturing. I asked about the rr350 alloy if that was what he was using. He said Porsche stopped using it and were using another alloy for the 3.6 turbo and later heads. So he was using the newer alloy, whatever that is for the singer heads. The rr350 is much harder to machine than the newer alloy and also the other types of heads.

[JFairman]

I have '76 930 heads and they don't say RR350. They work.
The '87 heads that were on my motor do say RR350 so it may depend when they were made.
Those 935 heads appear to have been cast in July 1979 if the "7-79" is accurate.

[RarlyL8]

I have a set of those as well that I hoped to someday use on a retro-build. I was told that the oil passage seen in this photo will prevent them from being practical for street use. There isn't anything practical about the ITB's or twin turbo plenums either so that engine may end up as garage jewelry.

[boosted79]

Is that passage to get oil down into between the exhaust valve stem and guide? The guide must be drilled thru that port after installation? Neat idea, would use some oil but who cares in a race car.

[heliolps2]

Cool stuff

[boosted79]

A dab of JB Weld or silicone in that groove would make them street friendly but if they're really worth 10k sell them and buy some street heads.

[RarlyL8]

I can't imagine there worth anything near that but I have no idea. Sent an email to Vaz but haven't heard back yet. I won't use them if they have value to someone building an actual 934/5 engine.

[faapgar]

Hi,I converted a lot of stock heads to this style.Got the tip from my school buddy Peter Dawe when he worked for Andial.You consume some more oil but the valve guide lives.Only downside is a puff of smoke on startup as a result of the oil following gravity from the intake valve spring well past the guide to the exhaust system.Looks deathly but actually is healthy.Ciao Fred

[VZ935]

I don't know why but for some reason 935 engine parts do not bring the money RSR parts do. That being said here are a set of my 935 heads. They are perfect and ready to go. If someone wants to give me 10K for them I would most likely sell them... though maybe not because I kinda need them

[RarlyL8]

Pretty wild that 3 sets turn up at the result of one thread.
I think the original poster is selling P&C with his heads for $10K. Any ideas on what the heads alone sell for? Faapgar what did you charge for the conversion? Mine also have the flame rings, dual plug, big valves, and the oiling mod.
Sorry if this mucks up the thread, I'll move on if not appropriate.

[Speedy Squirrel]

Originally Posted by Ken911

Yeah when I took my heads to xtreem to have them twin plugged and ported. He had a bunch of the singer engine heads he was manufacturing. I asked about the rr350 alloy if that was what he was using. He said Porsche stopped using it and were using another alloy for the 3.6 turbo and later heads. So he was using the newer alloy, whatever that is for the singer heads. The rr350 is much harder to machine than the newer alloy and also the other types of heads.

The 993 GT2 and GT2 EVO heads were RR350:



So the 993 3.6's were RR350. Here are Fairman's '87 heads, also RR350:



From an engineering viewpoint, I see no reason to use RR350 on something not intended to last 100,000 miles. Those kind of high nickel aluminum alloys are designed for long term tensile strength at 600 F+; probably not needed for 24 hours of hard racing. Also, I thought the 935's had the cylinders and heads e/beam welded together. That would make even less reason to specify RR350.

[Ken911]

hmm well maybe it was a later version turbo head he was talking about. I was thinking 3.6 maybe because all the heads were a 3.6 pattern.