Silicone Valve Cover gaskets

[iamchappy]

I installed 70.00 Silicone Valve Cover gaskets on my engine about 4K miles ago thinking that they were the way to go. I developed a leak on the lower cover and removed the cover this morning, the gasket split along the bottom . have you seen similar failure like this what do you recommend.

[jluetjen]

How tight were the nuts?

[iamchappy]

They may of been to tight was my first guess. I did not torque them but felt I applied about 10lbs on each, I used a cordless screw gun with a socket with the clutch set at 6 which i felt was fairly light.
what is the proper torque.

[kstylianos]

You can't torque those nut anymore than 8 ft/lbs or the silicone will tear. The manufacturer suggests 6-8 ft/lbs. They work great if they are not torn, but once they tear, they are useless. I tried to be really careful with mine, but they still tore.

-Charlie
(who has a small tear in his new silicone gaskets)

[iamchappy]

Chances are the others are split also but have'nt started to leak yet. Are they really an improvement over the stock ones. I came across some this morning on ebay for 32.99 should I spring for another set.

David

[kstylianos]

$32.99 is a great deal. Get a good in/lb torque wrench and use an initial torque of 6 ft/lbs. Tighten them up a little more (not exceeding 8 ft/lbs) if they leak.

[iamchappy]

I ordered up another silicone set, and went and picked up a factory set from the dealer just now. All my bases are covered. I still have the original covers not turbo, is it possible the covers are no longer flat and caused them to bite into the gasket more. since I am running the 3.0 in a 914 with thickly rienforced control arm brackets there is not much room for them without having to grind a lot off of the turbo covers. Maybe time to ugrade and grind.
David

[kstylianos]

I still have the original covers not turbo, is it possible the covers are no longer flat and caused them to bite into the gasket more.

That is a very good possibility. If you get a chance, place them down on a FLAT surface and see if you can pass light between the gasket surface and the table (or what ever flat surface you're using). If they are very warped, you can possibly feel them 'rock'.

If you have a machine shop near by, you can possibly have them true the surface depending on how warped they are.

[Superman]

Glass is usually used as a "flat" surface, since few other surfaces can be reasonably assumed to be flat. Few are flat. Glass tends to be flat.

JW puts valve covers onto a very big belt sander, as a way of truing the surface.

[snowman]

The best gaskets and price are from

www.realgaskets.com/files/automobile.htm

These are aircraft quality gaskets and work very well. DO NOT EXCEED torque specs or they will fail. Your valve covers are very likely so warped that even the silicone gaskets cannot accomadate the bend. Have them resurfaced or replace them with the turbo ones.

[BGCarrera32]

And FWIW, 6-8 ft.lbs. is like NOTHING...(be gentle)

[Wayne 962]

Originally posted by iamchappy
I ordered up another silicone set, and went and picked up a factory set from the dealer just now.

Does anyone realize what supports this board?

-Wayne

[Wayne 962]

The stock gaskets work perfectly fine if you use the Turbo valve covers, and don't torque them with the grip of death...

-Wayne

[snowman]

Wayne,

We all know who supports this board. Honest free flow of info will do you more good than harm, in my opinion. So do what all the others are doing and add these gaskets to your parts, with the approiate markup of course. I suspect you may be able to get a additonal discount as well, if you order enough and ask for one. Many of us are lazy enough to just order it from you, even though it may be a few cents cheeper somewhere else. Convienence is worth something. For those of us who are ultimately CHEEP, you can't get them anyway. I tend to opt for the more expensive route, because I am LAZY as well as CHEEP.

[aigel]

Thicker gaskets are not better. The thought behind thicker gaskets is that they will take up slack where part's aren't perfectly flat. The idea backfires though. The thick gaskets will promote warpage because the bolts pull down in one spot while the thick gaskets supports the points furthest away from the bolt. This tends to warp things.

The way to go is to make sure your mating surfaces are flat (a straight edge is the way to go, not a piece of hardware store glass) and bolt it up with a stock type THIN gasket. It will not leak if your surfaces are flat. Also, torque specs if using a thin gasket and flat parts are less important due to the same reason mentioned above.

George

[snowman]

Originally posted by aigel
Thicker gaskets are not better. The thought behind thicker gaskets is that they will take up slack where part's aren't perfectly flat. The idea backfires though. The thick gaskets will promote warpage because the bolts pull down in one spot while the thick gaskets supports the points furthest away from the bolt. This tends to warp things.

The way to go is to make sure your mating surfaces are flat (a straight edge is the way to go, not a piece of hardware store glass) and bolt it up with a stock type THIN gasket. It will not leak if your surfaces are flat. Also, torque specs if using a thin gasket and flat parts are less important due to the same reason mentioned above.

George

I can't agree with this based on recent experience with a 911T. I stubbornly tried several times, each with new gaskets (green, grey, and green again), as well as having the covers surfaced twice and checked with a machinests straight edge each time. The thing just would not quit leaking until I used the silicone ones. Of course these were the non turbo covers, but I figured if the factory could get it out the door without leaking so could I. NO such luck. I also had to use unmentionable stuff on the chain covers, which were new ones supplied with the tensioner upgrade.

[911gilley]

I just ordered and received today the "Tune Up" kit with my second big order from Pelican. It includes the grey valve cover gaskets (all graphite I think). Should I just put them on dry?

Wayne is saying yes but don't over-tighten; others are saying use some additional sealant on them.....and what about the chain covers?????? I've read Wayne's books and don't remember seeing anything regarding additional sealant on gaskets. I'm Confused.

[aigel]

Originally posted by snowman
Of course these were the non turbo covers

Well, that's your problem right there. The factory might have gotten them out without leaks but not for long either. Aren't those pre-turbo valvecovers magnesium? The thermal expansion mismatch haunting us again, combined with the flimsy design.

And to answer Ed's question: Gaskets only. And if there was no gasket, use your favorite case sealer.

George

[911gilley]

Thanks George. It makes sense. Will be putting it together with gaskets only (both valve and chain covers).

Snowman, what was the "unmentionable" stuff you used on the chain covers?

-Ed

[snowman]

ed,

You really need turbo valve covers for any chance of sealing the thing without some kind of special additonal goop or silicone valve cover gaskets. Additonal goop is bad because the frequency the covers must be removed for valve adjustments. The silicone valve cover gaskets are great because they should last indefinately with proper use and do not leak with either type of valve cover. BUT caution, you cannot use nylocks nuts on valve covers with silicone gaskets without the chance of ruining the gaskets. ONLY 4-6 FOOT LBS of torque can be used and it takes that much just to turn a nylock.

On the chain covers I would suggest non hardning permatex, Ford gaskacinch, or the stuff Wayne has suggested, Cuirl T . Grey silicone also works well here, but must be used with utmost caution so none of it comes off and falls in the engine. When I use it in this kind of situation I spread it on paper thin. It also works if you apply a very small, consistant bead to one surface, let it skin over and then put the cover in place, without any gasket at all, ie a gasket replacement. This is now being done by all the major car manufacturers in production so you can't say it will not work. esp since they guarentee the things for as long as 100k miles now. I would NEVER do this on a Porsche valve cover however. The reason is that it is a major project to clean the stuff off. In any case the chain cover gaskets do not work well without some help..