With my 390 I tried to make the cork gaskets work but.... atlas, they only leaked no matter what I did. So I found a parts desk guy that I trusted and asked him if there were ANY neoprene gaskets made for the 390 and he looked it up and said YES. 2 days later they arrived and that afternoon the engine was buttoned up tight. Never leaked again.
This argument has been going on for years and has gone so far as to involve everyone fro the hippie tree hugger all the way up the chain of command to the very oil barons that dictate who uses what in this country. I like cork and have used cork for many years with only a minimum of leakage. I have to suffer the slings and arrows of those more ecologically minded than I as to the story of the entire life span of the cork tree and how brutal the harvest of the bark can be to the old trees. Rubber gaskets just don't seal as good as cork and my opinions here left me under the gaze of the big seven Oil conglomerates. Yet I will stand my ground and stick to what mother has provided us for many years. I doesn't like to comply when the time comes to remove the cork seal (Rare though that may be!)but I think the trade off is fine with most cork aficionados. Cork if you can get it!! If not ,.. Then Rubber? It's pretty simple for me. Dave
I simply use silicone on sheetmetal valvecovers. When I worked at a SAAB dealership, we had these cast aluminum valvecovers whose sealing surface were machined out to accomodate rubber gaskets. I have never seen one leak and you could remove the valvecover for maintenance, without needing to replace the gasket. I suppose, one could bring their own cast valvecovers to a machineshop to get CNCed likewise. So, now you can go back to hugging your trees
Beware...the big seven are watching this. I see an unmarked Black helicopter circling my house right now! The use of plastic liquor bottle stoppers has driven down the demand for cork and the cork farmers are tearing out the cork trees and putting in more profitable crops like Eucalyptus. That means that cork gaskets actually create a demand for the material, thus the trees. Studies also show that regular harvesting generally improves the trees health and vigor. They don't have to cut the trees down to harvest so what the treehuggers are talking about is beyond me, they trees are very huggable. In any case cork gaskets have neoprene or other materials in them, they're made with granulated cork, not big chunks off a tree. Cork valve cover and pan gaskets are old school, can't use them more than once normally, the tear, they leak more often than not ,and the old ones are a pain to scrape off.
The bigger problem I remember from engines with stamped steel valve covers retained with only a few bolts was distorted covers from previous overtightening or missing load spreaders. Address those issues and examine the head castings at the sealing surface for flaws that will leak and either should be fine. I used to be able to buy cork gaskets that were rubber coated which I preferred. I have no idea if they are still available.
In my 23 years experience in auto parts I have found that neoprene gaskets seem to work the best if installed properly, the trick is to not over tighten them and always put them on dry. A small amount of rtv can be used only to hold them in place. If cork gaskets or paper gaskets are used a very thin coat of rtv on both sides can be used but the applied rtv should be allowed to vulcanize until no rtv comes off on your finger when touched. This "curing" step is what makes rtv work every time.
Listen to the NAPA man. He knows what he's talkin about! We no longer drive Model T Fords so why use Model T gaskets on our late model cars....? Let the tree huggers hug. Use neoprene rubber gaskets.
I've had the best luck with the Mr. Gasket blue cork. They come with a life time warranty against leaks. So far, they've done me well. Now, for the tree huggers: If the bark is not harvested off the cork trees, they die. Removing the cork is necessary to the life cycle of the the trees.
Seems like a waste spending all that money on clothes, putting them on, then removing them again over and over. Are we BARKING up the wrong tree?:banana:
I've ALWAYS used cork, with a couple mods, will last virtually forever. Make sure the cover is clean and straight, use weatherstrip adhesive to glue to the cover - let dry. Use wheelbearing grease on the head side, after clean and dry. Tighten snugly - you're done! Never had a leak, or a comeback!
Yeah, we should try wearing bark, instead. It's plentifull and costs nothing. In fact, cork is also used as floor insulation. It has a high coefficient of heat-retention. Maybe, someday they will introduce cork genes into our posterity, so that they will be born with corklike skins and be able to repell the effects of low temperatures, without having to put on anything except diapers after birth and before natural death Are you going to leave it to our imagination, by not telling us in detail how you were using those corks with them?
