Persistent rocker cover stud drip

[Uncle]

I've got a 3ltr SC motor with turbo lower covers on it. My drivers side has a persistent oil drip/weep on a 6 of the studs, Oil makes it's was down between the thread of the studs and the nut then drips on to the exhaust.
So far I've replaced the rocker cover as I thought it might be just warped enough to be placing more load on some studs than others. After this didn't fix it I replaced the paper gaskets with silicon ones from our host along with new nuts and crush washers. I torqued them down to the factory spec but they still leaked as much as they ever have. After this I packed the sh!&'s and torqued them up to a crazy 13nm. I know right, I am a wild man!
Anyway this also made no difference after a drive of 30 minutes and getting the oil up to temp they all still had a drip of oil sitting at the end of the thread.

For the record the seal around the edge of the cover is fine with no leaks at all.
Its a problem I don't want to put up with as I'm 99.% of the way though converting to turbo/efi and its the same side as the wastegate. Wastegate flames and heavy oil vapour sounds like a bad idea to me..

Thoughts?

[afterburn 549]

Install RSR "O" rings on the rocker arm shafts ..After taken apart a few times by those who are not careful can result in some scratched bores...

[Lapkritis]

Grease the base the stud base under the nut thoroughly before putting the nut on. Use something chemical resistant such as Dupont Krytox. Put enough on that it forms a seal of its own between the stud and the cover.

Edit: inspect your covers for tiny cracks around the holes. They do crack... if necessary replace.

[Uncle]

It has a new (less than 3 hours old) cover on it. I also checked the old cover for cracks thinking that might be it but no joy.

[Steve@Rennsport]

Originally Posted by afterburn 549

Install RSR "O" rings on the rocker arm shafts ..After taken apart a few times by those who are not careful can result in some scratched bores...

Precisely. It sounds like you may be seeing effects of rocker shaft leaks which drain down and look just like your valve covers are leaking.

[Tie Rod]

Question from a relative newbie...

So the original question of this thread was how to seal the valve covers to prevent a oil leak. If the engine is healthy, then shouldn't there be no oil behind the covers to leak out. The covers are there to seal the outside environment out? If oil is leaking out, then that would be a sign of an oil leak. Correct? The covers could be loose, warped or cracked but should not leak as there should be no oil there.

So my question is, would you ever just try to seal a leaking valve cover without sourcing the cause for the leak? Wouldn't oil just pool inside until it found another way out?

[afterburn 549]

At the end of the Rocker shafts is the out side world...
If you have leaks because they are 30 years old and been apart a dozen times...they drip on the floor.
The RSR "O" rings are a fun little project..and will not hurt anything by being installed
You have to have basic engine knowledge, valve adj skills.
probably drop the exhaust to get it out of the way...depends on whats there

[Lapkritis]

Originally Posted by Tie Rod

Question from a relative newbie...

So the original question of this thread was how to seal the valve covers to prevent a oil leak. If the engine is healthy, then shouldn't there be no oil behind the covers to leak out. The covers are there to seal the outside environment out? If oil is leaking out, then that would be a sign of an oil leak. Correct? The covers could be loose, warped or cracked but should not leak as there should be no oil there.

So my question is, would you ever just try to seal a leaking valve cover without sourcing the cause for the leak? Wouldn't oil just pool inside until it found another way out?

The inside of the cover is the natural oil lubricated environment of the engine. I guess you could stop the leaks by draining all the oil from the engine but then you couldn't run it.

-Andrew

[afterburn 549]

I think "Uncle" is under the impression that if the gaskets are all good it should not leak anywhere.......
Which is not true ..well should be true.but
There are those nasty rocker arms shafts..and a few other places ...Places that look like ..but ends up being top of the engine like the oil switch so often

[E Sully]

While it is possible, don't be too quick to think the RSR o rings will solve this. I had a similar issue with one lower rocker cover. I have the o rings on the rocker shafts, and the leak was from around the stud.

[fredmeister]

Go to a good racing supply catalog like Pegasus racing or maybe Mc Master Carr and find flat washers with a rubber seal along the inside radius. I think they are called "seal washers" Buy a dozen or two and install them under the nylon lock nut in place of the aluminum crush washers. This may help stop the leakage around the studs but no absolute guarantee.


Edit: They are called "stat-o-seals" in the Pegasus catalog. Find the nearest english size for the studs as they are non metric.

Fred

[Uncle]

Thanks for the input guys. The rest of my motor is clean and dry. I've had the shroud off when I was going from the weber's to the 3.2 inlet manifold. Not a single sweat or oil leak and dry as a bone every single place other than 6 of the studs.
I've just replaced the OPS with a Turbokraft job to feed the turbo. Again bone dry there..

While the motor only has ~3,000 miles on it from a rebuild I'll look at the RSR o'rings.

[Tie Rod]

Okay, apparently I had an epic mental breakdown before I realized what I was saying/asking. Disregard previous question, I had my mind so focused on one thing I forgot the obvious and started typing..........feeling pretty stupid about now........an I mean stupid!!

Anyhow, I'll own it.

[KTL]

I have to give credit to Walt Fricke on this one...........

Lots of good suggestions here. One that hasn't been mentioned is Walt's observation. The threaded holes for lower studs on the cam housing are not blind holes. They pass thru all the way into the cam housing where the oil sloshes around. If the sealant on the threads is not good, the oil can migrate to the outside and no gasket, special washer or sealant is going to stop it. The only stopper is the nylock ring on the nut. But if you seal the threads in the cam housing, you're stopping the leak at its source.

Walt had actually suggested using acorn-style nuts (top of nut is capped, not exposed). Good suggestion if one is not prepared to remove the studs and seal them up.

[fredmeister]

Originally Posted by KTL

I have to give credit to Walt Fricke on this one...........

Lots of good suggestions here. One that hasn't been mentioned is Walt's observation. The threaded holes for lower studs on the cam housing are not blind holes. They pass thru all the way into the cam housing where the oil sloshes around. If the sealant on the threads is not good, the oil can migrate to the outside and no gasket, special washer or sealant is going to stop it. The only stopper is the nylock ring on the nut. But if you seal the threads in the cam housing, you're stopping the leak at its source.

Walt had actually suggested using acorn-style nuts (top of nut is capped, not exposed). Good suggestion if one is not prepared to remove the studs and seal them up.

Take a look at the washers I suggested. They will stop the leak as you describe it here because the rubber seal is at the junction of the thread on the studs as it leaves the housing. I think if you saw them as installed or thought about it you would agree with me......unless I am missing something.

Fred

[KTL]

Yep i've used the stat-o-seal washers on my carb fuel rails and also on my engine case adapters for AN braided cam housing oil supply hoses. You're correct they at the shank/threads of the fastener. I stand corrected!

[timmy2]

McMaster-Carr
Click on metric.
$15 for 10 if you want to try them.

[notmytarga]

Would this be the exact sealing washer? M8?

http://www.mcmaster.com/#cadinlnord/93786a150/=mjf087

[KTL]

Yep thats it