Cometic Head gasket Hole Pattern Mismatch

I didn’t see a posting to indicate Bill Terry’s opinion, and would like to know what he says.

Regarding the Cometic, I had the same question when I rebuilt a 3.8 e-type motor a couple years ago. I got the gasket from Engel Imports (formerly Terry’s Jaguar Parts), so I called them. I was told by their salesperson that the small size of the water passage ports was intentional and to put the larger holes to the exhaust side. Unfortunately, I can’t give a testimonial about the engine because it hasn’t run yet.

I sent a full set of pictures to Bill Terry and spoke to him late yesterday for his verdict. He agreed the current quality was pretty ragged but his big concern was the mislocation and partial obstruction of the already small coolant holes. Given the current batch of gaskets he recommended I go back to Payen.

Regarding the size of the holes, he offered no theory as to why they might be better. But said he has been using that style for years in both race and street performance engines without issue.

As for me, I still cannot reconcile how restricted flow is somehow better but I accept that empirically it causes no problems. That being said, I’m more comfortable that I have a Payen being delivered today.

Rick

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If I recall correctly, on the XK engine, there actually is no flow through the intake side of the block, down through the block.

Hi Robert.

I was agreeing totally with Tom’s last sentence (cautioning against lumping various disparate concepts into a single portmanteau argument).

Apologies for the lack of clarity.

Pete

You’re not recalling correctly then. Block, head and manifold.

Thanks for sharing Bill’s input. I have spoken to him about numerous issues over the years, and he is invariably gracious and insightful.

Got it. I misunderstood and thought you were agreeing with that Motor Trend article. I was really surprised that it would find its way into print. Luckily, I put a lot more faith in R&T than I do in MT.

I learned a new word (for me) from your post, too. And you used it quite creatively, as is your wont. Thanks, Pete!

At least thru the 140, the water flow from the pump does NOT go into the main part of the block…the water is forced into a 2 inch deep channel that runs the length of the block at the top of the exhaust side, then up into the head, thru the head, then out to the intake manifold and on out to the radiator.

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I have had this gasket in my engine ( stock ) all this year. Smaller holes than the one I took out. Todays run was at 90F with a humidex over 100F. I never got over 50 mph but the temp gauge never moved past 85c , its normal position.

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That is my understanding, too, and what I clumsily referenced.

Forgive me folks but did we decide that the Cometic head gasket was ok, or not?

The final answer I got from Bill was that the design of the Cometic was fine (i.e. the small coolant holes) but the execution of this particular batch of composite .059" Cometic gaskets was not usable. Incidentally, I received the Payen gasket and the quality difference is night and day. I hope Cometic gets their act together because the two they sent me were trash. And at twice the price of a Payen a pretty bad deal.

Rick

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To add a slightly different engine data point into the discussion, I recently got a new head gasket made for a 3 1/2 litre pushrod six for Mark V. That gasket came in a cardboard envelope which says Cometic. The gasket material is one layer of Victor Reinz AFM 20 at 1.10 mm nominal thickness and steel crush rings at cylinder OD. The only markings I see on the gasket are the Victor Reinz markings, I can’t tell from the gasket who made it.

Victor Reinz Head Gasket Material AFM_20_en.pdf (510.4 KB)

I can answer this one. I was told by Terry’s Jag (not Bill Terry) that Victor Reinz made the best material for this application so Cometic is using their material. They are still made in the Cometic Ohio plant even though there is no Country of Origin on the labeling.

Rick

Has anyone ever used a copper gasket ?