Valve Cover Gaskets

CHILI · CHILI's Garage

I have leaks (imagine that!). I used the gaskets with the silicone bead and have turbo valve covers and used all new hardware. Factory stuff. Still leaks.

Has anyone tried these? They are offered by Appbiz. Or, when you all say use the silicone ones, are these what you are talking about? I assumed you meant the silicone beaded ones that I'm running. Maybe I'm wrong?

CHILI · CHILI's Garage

BTW, forgot to say that the image is not the best. It's from their site. But, they are 100% silicone. About 1/8th of an inch thick.

Groesbeck Hurricane · 02-04-2004, 09:12 AM

What did you torque the nuts down to? If you overtorque, that is just as bad as undertorque.

Also, are your rocker arms installed correctly? Do you have the little RSR seals on them as well (this is an extra step that is not necessary in all applications, as I understand it...)?

There are some other causes to leaks in this area. One person I talked to applied Teflon tape to the stud threads to give an extra seal capability, though I am not suggesting anyone does this.

CHILI · CHILI's Garage

My mechanic did it. They leaked, so I tried to tighten just a little bit more. Still leaked. Can't remember the exact torque setting, but it was pretty low. What are the little "RSR" seals?

The tape might be the way to go, as it seems that it might be coming from the studs. Can't tell if it's just gathering there (lowest point) or if it's leaking from there.

fuelie600 · 02-04-2004, 09:23 AM

Our host sells these. I haven't used them yet, but I have a set on order. The part number is PEL-SIL-VLGK

Good luck...

CHILI · CHILI's Garage

Quote:

Originally posted by fuelie600
Our host sells these. I haven't used them yet, but I have a set on order. The part number is PEL-SIL-VLGK

Good luck...

Forgot that Pelican sells the Appbiz stuff now. Much cheaper, too. Thanks for the reminder.

Anybody currently running them?

scottb · 02-04-2004, 10:25 AM

I use silicone gaskets on the helicopter. They work great, and are reusable. The trick is not to tighten them too much, or else they distort and will leak.

CHILI · CHILI's Garage

Quote:

Originally posted by scottb
I use silicone gaskets on the helicopter. They work great, and are reusable. The trick is not to tighten them too much, or else they distort and will leak.

Well if they're good enough for a hellicopter, then I'm in! if anything goes wrong, I can at least pull over. Not really an option while you're in the air.

KTL · 02-04-2004, 10:30 AM

Hefty silicone gaskets + new fasteners = leaky

would lead me to believe the valve covers are warped. Possibly overtightened in the past?

The torque spec for the valve cover M8 nylock nuts (gotta make sure to get the right nylocks- the hardware store ones can melt) is really light. 6 ft-lbs. I believe. That's not real tight.

scottb · 02-04-2004, 10:34 AM

Quote:

Originally posted by KTL
Hefty silicone gaskets + new fasteners = leaky

would lead me to believe the valve covers are warped.

You might try putting the covers on a flat piece of glass and see if they are warped. The nice thing about the silcone gaskets, at least from my experience, is that they're somewhat forgiving of minor imperfections.

CHILI · CHILI's Garage

I'll give it a shot, guys. Thanks for the info.

onewhippedpuppy · 02-04-2004, 10:40 AM

I just put the Pelican silicone gaskets on my T this weekend, as well as turbo lower valve covers, seems to have stopped my leaks. I used all new fasteners/ washers, torqued them to 6 lb/ft. As I understand it, the all silicone gaskets are re-useable? That would make valve adjustments a little cheaper.

banjomike · banjomike's Garage

In the 911 Maintenance course Jerry Woods and Bruce Anderson specifically warned against using sillicon gaskets for this application. Sillicon is flexible and variations in the tourque will cause leaks and can warp the covers.

Zeke · 02-04-2004, 01:34 PM

Quote:

Originally posted by CHILI
My mechanic did it. They leaked, so I tried to tighten just a little bit more. Still leaked

In this case, that is not the way to go. IMHO, the covers won't leak even if you just hold them there. The 6 lbs., or 72 inch pounds, is more likely to help the nut not back off than anything else. Unless you can depend on the thread sealant in the nut.

I say they are warped. This is a big problem with any large device, be it an oil pan on a Chevy or a Weber carb body when it is held by a few nuts spaced apart. You tighten and only the area around the nut compresses. You tighten more and it keeps compressing until it's bent. The area between the nuts/studs is only gonna go so far. The idea is to have all of the surface go just as much as "so far" and no more. That's about as even a pressure as you're gonna get. Once you overtighten some thing like this, it has to be straightened out. On a piece of glass or whatever.

I've stopped a LOT of carbs from leaking at the float bowl by checking the surface before doing anything else. Most old carbs that come my way are bent from over tightening at some point.

73911guy · 02-04-2004, 01:50 PM

I had valve cover oil leaks when I used the old style graphited gaskets.

Bought new valve covers - top and bottom - as well as a Snap On torque wrench.

New valve covers still leaked with new graphited gaskets when torqued to spec.

I bought the "used on airplane" silicone rubber gaskets when they came out. They leaked worse than the graphited gaskets ever did. The torque spec was solow I was afraid the valve covers would fall off going down the road.

Next was a set of "Wrightwood Racing" gaskets with the silicone rubber bead on them. They solved 99% of my leaks.
I'll stick with them.

Jim