Guys,
I have seen samples of Christian Garibaldi's work, and it's quite flawless...

Oh and the Porsche club seems to endorse what he does and says...

Nice pic Christian...

Greg

 

Christian,

the flash might make the inner cylinder surface look rougher than it really is. The top of the cylinder where the head contacts the cylinder directly was intentionally left rough. That way they cut into the head and give some extra protection against too much movement or so I was told. The fire ring area is much smoother.

Ingo

 

Oh, I figured that it could be the picture. its tough to tell from a photo

 

Garibaldi,
A few questions:
Are the fire-rings commercially available for the 964 or are they machined to order? Are they solid material with a particular profile, or are they just square/rectangular? What tolerance do you allow for the compression of the head onto the barrell so that the flame-ring bites into the head?
Basically, I have an engine that also needs something like this without going to the expense of new pistons/barrells and skimmed heads. Any help gratefully received.

 

Yes, those rings are commercially available. They are the same rings used on the Turbo.

 

Call Protomotive, they have the right stuff for your needs,cheers,Sonny.

 

This is a really interesting thread, I'm hoping to get a little more information if anyone knows it.

Do you mean the rings that are used on the 964 turbo? I've had a look on the 964 PET and the numbers it gives are either:

964.104.115.20

or

964.104.381.01

Any idea which?

And the big question, does anyone know what the dimensions and tolerances are to machine the top of the cylinders to? I presume it's the same as the heads the rings were originally designed for but I don't have any heads to measure it from!

Finally, looking back to the start of this thread there are example photos that show the cylinder machined for the ring and the head machined for the ring - which one needs to be machined or doesn't it matter?

Sorry for all the questions, just trying to get my head around this!!

 

wow ...let me understand this thread correctly. I am not a mechanic and not even that bright so speak in laymans terms please. It would appear that you can have your heads machined for an early 964 such that they will accept a head gasket ? Where do you send the heads ? Where do you buy the gaskets or what brand are they part number ? How many motors has this been done on to fix the flawed design ?

 

This is exactly what I thought on this but....

After speaking with my engine builder & machinist - he showed me the sealing ring (993 type I think) that you can machine the heads to allow fitment and there was so little material left on the mating face he gave me the choice but advised against it so I didn't.

Just my opinion and I think there are lots of people who have done or do carry out this mod.

 

Email Mark at Exotech (prschmn@comcast.net) or call him at 603-382-3599. He's done tons of heads like this and has never had trouble. He does all the machine on the heads and cylinders and supplies teh proper sealing rings. His motors include some 500+ HP RS style motors and a couple of forced induction units.

 

Sorry for bringing up and old post, but this solution to head gasket failure seems very interesting.
Any update or additional info?
Thanks,