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valve cover sealing.  Rate Topic 
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 Posted: 08-23-2011 02:13 pm
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Dan (Florida)
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Oil leaks have been my constant companion lately and I may have found a solution for one of them.   Getting valve covers to seal properly without leaking is somewhat of a crap shoot. Sometimes it works and sometimes not. Since the bottom edge of each cover is required to seal  under a pool of oil  the bottom edge is all important.  When you first put the cover on with all of the gaskets and sealers you will notice that the cover can rotate a bit around the round parts on the ends.  If the screws on the upper side are tightened first  the cover rotates away from the bottom surface.

My dea is to tighten all screws hand tight  and alternately snug down upper and lower screws. when all are snug, loosen the uppers and tighten the lowers  several times until the cover no longer rotates downward. This worked for me with paper gaskets and semi hardening permatex.  I have had semi success with different gaskets and sealers and figure that the secret is in the tightening sequence.

let me know if it works. I would be interested to know if retightening  a leaking cover  would stop a leak.

hth  Dan

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 Posted: 08-23-2011 02:41 pm
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Jensen Healey
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Hi Dan,

Good info! I'll try it next time I'm in there.

I think most cam covers have been overtightened sometime in the last 38 years and spread at the bottom. I've had good luck using the silicone or rubber gaskets installed dry. I did have to do the exhaust twice last time to get it tight.

Kurt

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 Posted: 03-04-2021 10:20 pm
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Ralph H
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Anybody have anything helpful to add to this 10 year old thread I am just about to put my cam covers back with silicon gasket and always like to hear from the collective genius of this forum. Thanks all

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 Posted: 03-04-2021 11:52 pm
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redracer
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Just use the red ones JHPS sells(has instructions) with new seloc washers and you should be fine.
Mine have been on 25 years with no problems

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 Posted: 03-10-2021 01:07 am
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chrisl
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Yep - Bret is right

I've used the red silicon gaskets on my J-H and GT for years, and the seloc washers. Both highly recommended.

I also bought a small torque wrench from a bicycle shop to get the right torque setting to tighten the bolts.

This, the red gaskets and the seloc washers has wiped out (arf arf) my oil leaks.

At least the ones from the valve covers...

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 Posted: 04-20-2021 10:35 pm
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Ralph H
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as directed I did just as Chrisl and redracer indictaed and the cam cover leaks are GONE. A new oil gauge takeoff and some work on the Transmission shift tower and I am almost spot free under the car after a drive. some small specs showing up on the floor near the front of the engine on the left side and fresh oil on the front lower area of the block still to sort out.

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 Posted: 09-19-2021 09:01 pm
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mtechwim
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Used the black ones, that was not ok, the bottom one keeps leaking, now i have the green one, after a first test it stays dry.

The black ones look like to been pressed out, using the correct torque.

I also used another coffer, because the old one looks not strait.


Will have a look after 2 weeks than i am home again.

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 Posted: 09-19-2021 10:40 pm
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redracer
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Here's the instruction sheet(Greg at JHPS sells them) that should be helpful:[img][/img]

Attachment: J-H Cam Cover Gasket Instructions.jpg (Downloaded 47 times)

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 Posted: 09-24-2021 08:14 am
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Esprit2
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The key point to getting a dry joint with the rubber gaskets is to install them dry, with no sealant. The JHPS instructions say that in bold letters... believe it.

Everything... cover, cam carrier & gasket must be thoroughly cleaned, OIL FREE, and dry! Pay particular attention to the bottom side of the exhaust cam carrier.
It's tilted over at such an angle that more oil can run out onto the joint surface as fast as you clean it off. You'll have to remove excess oil out of the cam carrier first, then solvent-clean the joint surface to oil free and dry. Then assemble with everything dry.

Have you ever pinched a fresh/wet watermelon seed between your fingers, and shot it across the yard. That's what happens to the rubber gasket if it's installed wet, then pinched between the cover & cam carrier. And WET can be oil, sealant, sweat, hand lotion, or anything else. Install the gasket dry on dry, oil free surfaces!

Then do not over torque.

Regards,
Tim Engel

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 Posted: 09-25-2021 11:07 am
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chrisl
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I'll second everything Brett and Tim's said above.

Have used the seals sold by the JHPS and the instructions that come with them; it has worked for me every time. I even bought a torque wrench from a bicycle shop to get the right setting. And a thread chaser to clean out the bolt holes. It was worth every cent.

It's also worth getting some Seloc washers to put between the bolts and the cam covers.

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 Posted: 09-26-2021 10:31 am
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discogodfather
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Just my 2 cents: I have found that even after cleaning everything and using the newer high quality rubber gaskets that things leak when only an initial torque setting is applied.

My theory is that these cam covers and housings have a lot of distortion in them. First there is the originally low tolerance of the manufacturing, second there is the now 40-50 years of time spent aging, and thirdly there is the various heat/stress cycles everything has gone through many times. This third issue also included people not torquing the covers down correctly over and over again while #1 and #2 were also adding more variation to the mix.

The result is covers and housings that aren't uniform. Even if we clean it perfectly and torque it right, things just leak out of the variations.

My remedy to this (and I do have BONE DRY covers) is to do the whole clean and then torque, but then return to the bolts afterwards and individually hand tighten them after the cover has had a heat cycle. What I have found is that on warped covers, the leak begins immediately, and when you go to torque the cover down again it is clearly loose and not holding the original torque value, and is sometimes even loose.

The hand tightening (with care and patience) cinches the gasket down further, allows the gasket to form into the uneven surfaces, and plugs the gaps and stops the leaks.

This is a long process of heat cycling then applying the torque again, until the gasket is ultimately seated and doing its job. You can go the route of simply retouring, but I have found that just light pressure by hand works wonders because most of the time you are simply re-applying a little lost torque when the gasket moved because it was sitting inside of a particularly big gap or inconstancy in the local area of the bolt. You are never going beyond the 14 inch pounds necessary, you are just adding in the 2 or 4 or whatever inch pounds BACK into the bolt to help it massage the gasket into deforming to the gaps it is attempting to seal.

It takes a few times, and often some bolts need only 1 or two cycles to get sealed and others need like 5-6 cycles. The result is a fully dry setup that should be torqued to the correct amount, minus a few inch pounds here and there.

Took me 15 years to figure this out.

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