What head seals are you using in 964?

[billjam]

Are the rolled steel 964 head gaskets (96410411520) really a direct replacement for the graphite seals (96410411500) used in 1992 3.6 engines?
I much prefer to replace my original graphite seals with the same type, but I am being told that the newer steel seals are a direct replacement even though at 2.5mm wide, they are way too narrow for the 4mm wide grooves in my barrels.
They will have 0.5mm of crush, so that may be enough to do the job, but it just doesn't look right.

What are you guys using when rebuilding 3.6 engines which originally had graphite seals?

[billjam]

Anyone?
Surely someone knows which way to go here

[Flat6pac]

I built a 964 a few weeks ago and swapped in the heads and the P&Cs from a later car that had the CE ring groove. Metal gasket in the rebuild kit did the job, compression was on the mark.
Bruce

[billjam]

Thanks for your input Bruce, but I'm not sure that it helps.

I already have good barrels with the 4mm wide groove for the graphite type gasket.
I need to know if the later steel rings (2.5mm wide) can be used in these barrels.

BTW, what's a CE ring groove? I've seen it mentioned before, but don't recognise the term.

[Flat6pac]

Its the groove in the top of the cylinder for the ce ring to sit in.
Bruce

[billjam]

I meant what is "CE" ? Not familiar with that term.

Tks for the bump. I am still looking for an answer (on three forums!)

I need to know if the later steel rings (2.5mm wide) can be used in the barrels with 4mm wide grooves for the original graphite gasket.

[NoEardGoat]

Bill, Talked with my Porsche machinist and the graphite rings are still available. I am going to order a set through him for my project. Let me know if you would like me to order an extra set for you.

[Steve@Rennsport]

Originally Posted by billjam

I meant what is "CE" ? Not familiar with that term.

Tks for the bump. I am still looking for an answer (on three forums!)

I need to know if the later steel rings (2.5mm wide) can be used in the barrels with 4mm wide grooves for the original graphite gasket.

You must machine the heads to accept the 993 head sealing rings.

We do these all the time on the early 964 heads and cylinders.

[billjam]

Originally Posted by Steve@Rennsport

You must machine the heads to accept the 993 head sealing rings.

We do these all the time on the early 964 heads and cylinders.

Steve,
That doesn't make sense to me. We must be talking about different things. Why would you need to machine the heads? The existing groove is in the barrels and is 4mm wide x 1.3mm deep.
Maybe this "CE" ring is much bigger than the steel 964 ring?

The steel ring, which doesn't have a spring inside, is 2.5mm wide and 1.7mm thick, like this ...


All I need to know is are these rolled up steel sealing rings (with no spring inside) a direct replacement for the original graphite seals.
The groove is actually too wide (by 1.5mm) and it just doesn't look right.
There is about 0.4 to 0.5mm crush on the steel seal when the flat head surface is bolted up.

[billjam]

Originally Posted by NoEardGoat

Bill, Talked with my Porsche machinist and the graphite rings are still available. I am going to order a set through him for my project. Let me know if you would like me to order an extra set for you.

I've sent you an email.

[billjam]

For reference, the steel 964 seal looks like this ...

[billjam]

I thought I'd resurrect this thread because I am still looking for an answer.
The original graphite seals seem to be difficult to source and some have suggested that the narrower hollow steel seals can be used even though their 2.5mm width is 1.5mm narrower than the groove in the top of the barrel.

Any help with a source of correct graphite seals or confirmation that the steel versions are OK to use would be appreciated.

[lucittm]

You said, "any help" so here is some. My turbo has the same configuration. I took the flat 4mm steel sealing rings out and put new flat 4mm steel sealing rings in, no problems. I had heard the earlier cars had problems with the round rings because the sealing surface area is so small (thin). With the flat rings you get 4mm of sealing area all around. The graphite was a bad design which became obvious only after many years of use.
If you must machine your heads to accept these rings, do it. Steve knows what he is talking about. Then your problems are solved, at least the head sealing ones. I would not think the cost is too great for this...

Mark

[billjam]

Thanks Mark, I appreciate your input but this part is different on a 964 turbo to a N/A 3.6. I have some of those rings for a '92 turbo - they are 0.5mm thick and 8mm wide.
Some model 3.6s use the roundish steel ring but it is only 2.5mm wide. Its height is OK as it will have about 0.4mm crush, but the problem is its 2.5mm width in the 4mm wide groove - doesn't look right.

I don't doubt that Steve know what he's talking about, but I think we must be talking about different models.
My barrels have a 4mm wide groove in them, so I don't see what help it will be to machine the heads unless there is yet another type of seal that would fill the groove in the barrel as well as the new groove in the head.

Found this pic of top of barrel with graphite seal in place (since removed) and steel ring type seal for comparison.

[WERK I]

Bill,
Which 3.6 are you working on? M64/01, M64/0?

[john walker's workshop]

it's not a "head" gasket, but rather a fluid barrier. the metal rings work fine.

[lucittm]

Bill,
You are correct. Those sealing rings in my car were 8mm wide, it has been some time since I was in there and I forgot how wide they were.

You have an interesting issue, I hope you get it resolved. This is the right place for it.

Good Luck,
Mark

[billjam]

Originally Posted by john walker's workshop

it's not a "head" gasket, but rather a fluid barrier. the metal rings work fine.

That makes sense. Obviously the cylinder-to-head faces do the real sealing as far as compression is concerned.
I'll go with the metal rings. Thanks John.

Mark, if you need a set of sealing rings for your turbo, I have a spare set of six ($10 plus postage).

Dave, for the record, the engine is an M64/02.