Torque for alloy valve cover

Just wondering if anyone knows if there is a torque setting for the aluminum alloy valve cover? Please e-mail answers to jwittman@stny.rr.com
Thanks,

Bill

Hi Bill,

With the wide flanges of the alloy valve covers, you don't need to over-tighten them. Doing so will just squeeze out too much of most gasket sealers, actually causing leaks instead of preventing them.

I just use hand-tightened, oversize/knurled cap nuts on the alloy cover on my TR4, which uses a flat cork gasket. The two fasteners were made from fancy chrome cap nuts bought at a local auto parts store and actually intended for custom air cleaners (needed to be drilled & tapped for the correct thread) and now have hard seal/washers under them. I generally have to use a rubber strap wrench to help loosen them. Once the car is back on the road, I'll see if they have any tendency to vibrate loose and, if so, might need to use some low-strength Locktite on the threads. I'll still use them just hand-tightened. Because of the larger diameter and knurling, they can be tightened a little more by hand, than could a standard nut. I don't know what the actual torque works out to, though, since there is no way to put a torque wrench on them. I would guess-timate it's no more than 10 to 15 ft lb though.

The type of gasket and sealers used on your particular cover might be important. There are essentially two types of gaskets used on alloy covers: o-rings and original style, flat cork. I would be careful not to overtighten either type.

The o-ring type don't require any actual sealer typically (this type might be the choice of someone who very frequently removes the cover, but the downside to an o-ring is getting a replacement eventually, since they are custom sized and fitted to the valve cover). I think most folks use a hardening sealer on one side only, to "glue" the o-ring into its groove in the valve cover. My Honda motorcycle uses a lot of o-rings and I can tell you the specially sized and shaped ones are very pricey!

The cork type of gaskets need some sort of sealer on both sides, because the gasket is less compressable than the rubber o-rings. There are many different schools of thought about this, but I tend to use a hardening sealer on one side to glue it to the cover, while the other side toward the head is coated with a non-hardening sealer. This will usually allow the cover to be removed/reinstalled a few times before the gasket needs to be replaced.

/ubbthreads/images/graemlins/cheers.gif

Bill,
Ditto what Alan says. Too, on my cast aluminum cover, I glue the cork on with Permatex Aviation sealer on the valve cover first. As you well know, cork is a natural material and has a tendancy to want to not keep it's shape whilst you are trying to glue it down. How many times have we found that the cork gasket has migrated in or out as we torque it down, while we try to push or pull it back into shape. I have resorted to using about a million clothes pins to hold it against the valve cover and using the Aviation sealant, allow it to sit at least over night to stick. You can adjust it to where it is close to perfect and just put it away til the next day. I then put a light coat of Aviation on the bottom and simply drop her in place. Be careful when using the clothes pins that you line them up squarely and not distort the gasket.


Bill