[v12-engine] cam cover gaskets interchangeability

( 1971 S3 etype : Ohope beach New Zealand) #1

Hi guys
Is it okay to use the later Gortex cam cover gaskets part nos
EBC 9628 and 9627 on my 1971 pre HE V12.

From what I read it appears OK, but I would like some expert
opinion.
Cheers–
Mark Brown 71 S3 Etype
Ohope, New Zealand
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(Ed Sowell) #2

Mark,

Don’t know that I qualify as an expert, but I used them on my car, also a
5.3L V12.

Is it okay to use the later Gortex cam cover gaskets part nos
EBC 9628 and 9627 on my 1971 pre HE V12.

From what I read it appears OK, but I would like some expert
opinion.
Cheers

Mark Brown 71 S3 Etype

Ed Sowell
'76 XJ-S coupe, red
http://www.efsowell.us/ed/myJag.html

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(Kirbert - author of the Book, former owner of an '83 XJ-S H.E.) #3

42southern wrote:

Is it okay to use the later Gortex cam cover gaskets part nos
EBC 9628 and 9627 on my 1971 pre HE V12.

It’s OK, but you might not want to.

There are two very workable ways to ensure reliable sealing of the
cam covers:

  1. Gortex cam cover gaskets in combination with an aluminum half
    moon seal.

  2. A new rubber half moon seal used with no cam cover gaskets at all
    – cam cover-to-tappet block interface sealed only with sealant such
    as Loctite 518.

It must be emphasized that rubber half moon seals should NOT be used
with a cam cover gasket of any sort. The rubber half moon seal does
not provide the rigid surface necessary for secure compression and
reliable sealing of a gasket. If it seals at all, it’ll only be as a
result of heavy gooping of sealant on everything, and it’s not likely
to last too long before it starts leaking.

Option 1 above will last the life of the owner of the car, it’ll
never leak again. Option 2 will last until the rubber half moon seal
disintegrates, which varies depending on the quality of the half moon
seal used but should last a good ten years at least.

Thing is, aluminum half moon seals cost money, and those Gortex cam
cover gaskets are extortionarily priced. Option 2 is a lot cheaper,
and you’re likely to have the cam covers off every decade or so for
valve adjustment anyway.

Don’t forget that you’ll want to replace the cam cover bolts as well.

– Kirbert

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( 1971 S3 etype : Ohope beach New Zealand) #4

In reply to a message from Kirbert sent Wed 1 Dec 2010:

Thanks Kirbert.
I have already purchased a couple of half moon seals.
You are correct in the assumption that I will have to have the
covers off again within 10 years.
So some Loctite and the jobs done.
Just some intake manifold gaskets to purchase, and I’m ready for
the winter valve stem seal replacement project.
I do have some of the older single intake manifold gaskets, however
I see the newer ones are one piece units. Are the older ones still
Okay, or are the newer ones an upgrade worth going with?
Thanks for the help–
The original message included these comments:

  1. A new rubber half moon seal used with no cam cover gaskets at all
    – cam cover-to-tappet block interface sealed only with sealant such
    as Loctite 518.


Mark Brown 71 S3 Etype
Ohope, New Zealand
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(Kirbert - author of the Book, former owner of an '83 XJ-S H.E.) #5

42southern wrote:

Just some intake manifold gaskets to purchase, and I’m ready for the
winter valve stem seal replacement project. I do have some of the
older single intake manifold gaskets, however I see the newer ones are
one piece units. Are the older ones still Okay, or are the newer ones
an upgrade worth going with?

Good question. There are SEVERAL varieties of intake manifold
gaskets used on the Jaguar V12, starting with the very earliest
versions being metal! Most are thick cardboard or fiber of some
sort, including the latest 2-piece versions. Honestly, I haven’t
heard of anyone having any more trouble with any one versus another.
They ALL should be installed with sealant, preferably something non-
hardening, and the nuts should be retorqued after the first coupla
runs and then periodically thereafter – they tend to loosen up, in
no small part due to the fact that the entire manifold, throttle
body, and air filter housing is hanging off that attachment and the
engine vibrations probably work them loose.

If you do get the current design 2-piece gaskets, it’s recommended
that you cut them into 10 pieces before installing! (The #3 and #4
ports can be left as a single piece) Just use some bolts to align
the gasket with one of the intake manifolds, mark around the manifold
with a Sharpie, and cut away the sections in between ports. If you
have an H.E. engine, it just makes things nicer – the chunks of
gasket suspended between intake ports just clutters things up in the
V. If you have a pre-H.E., though, it’s essential to cut up the
gaskets if you ever hope to change spark plugs again.

– Kirbert

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(Geekay) #6

Is there any update on this? Are the aluminum half moons still available?

Gary

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(Kirbert - author of the Book, former owner of an '83 XJ-S H.E.) #7
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(chris gruchawka 1988 XJ-SC) #8

I thought John had made a new run, I’ve been distracted and haven’t gotten the opportunity to install mine. You could contact him directly?

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(chris gruchawka 1988 XJ-SC) #9

Geekay,
I’ve attempted to “share” this link with Jonas. I think he will be in touch, if not give me a PM and I will assist.

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(John) #10

Hi,

Yes aluminium half moon seals are still available :wink: as well as upgraded oil feed banjo bolts (below half moon seals) and aluminium chain tensioner plug.

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(Steve Westbury) #11

John, do you happen to know what the dimensions of the aluminium bungs are, so that I can make them.

Many thanks

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(John) #12

What bungs are you talking about?

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(Steve Westbury) #13

Hi John,

I was thinking of the half moon aluminium cam cover bungs.

Also if I use loctite 518 will the cam covers be easy to remove in the future?

Regards

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(John) #14

Hi,
Yes, I’m making them myself. Reg. Loctite 518 I think it will work very well between head and tappet block and for sealing half-moon seals in place, but for cam covers I would use newer style 3-layer gasket.

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(Kirbert - author of the Book, former owner of an '83 XJ-S H.E.) #15

IF you have aluminum half moons, use a gortex sandwich gasket and apply sealant only around the curved underside of the half moons.

The idea of omitting the gaskets in favor of sealant all around is for using the OEM rubber half moons. It’s because the rubber half moons don’t provide a rigid surface for the gasket to be compressed against so the gasket will always leak there – probably between gasket and cam cover, actually.

I used Permatex Ultra Black on a project recently. It’d probably work as well as 518 for the cam covers and half moons, and it might be easier/cheaper to find. Note the assembly instructions for Ultra Black involve mating the parts up just tight enough to start squeezing the goop out and then let it sit for a while before fully tightening.

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