Fred Zwicker Posted August 14, 2010 Share Posted August 14, 2010 I have an original 1955 Pontiac Safari wagon with an original rebuilt V-8 engine and in detailing the engine, we removed the valve covers for painting. These covers had cork gaskets and did not leak. All of the old cork was carefully removed and it was stuck tightly to the inside of the valve covers in most places. We ordered new gaskets, but they were black rubber (Fel-Pro). 1) We installed them carefully, but they both leaked. 2) We removed them and carefully applied black silicone sealer to the rubber, including around the 4 bolt holes. All metal surfaces were spotless. They both still leaked.3) We removed these and started all over with a new set of the same black rubber gaskets (Fel-Pro). This time we were very particular and double-checked to be sure that the inside surfaces of the valve covers were dead flat. We used a light coating of gasket shellac to hold the gaskets in place to the covers only while installing. We did not use any silicone this time and we added a set of the flat metal plates at each bolt to distribute the attachment more evenly. At startup, everything looked good until we took it for a short drive. More leakage.*Note: We did not over-tighten the bolts, snugging them up and tightening about a half turn, which seems to be the proper procedure.I am now wondering about the advisability of using rubber gaskets for this application? I just ordered a set of cork gaskets and that will be our next move. We are getting frustrated. When we install the cork gaskets, what type of sealant (if any) is recommended? (One side or both sides?). The valve covers are original, are not rusted, and appear to be in perfect shape.*Note: The oil was just changed prior to all of this at a Quick Lube and they used 5W30 oil and it was marked, "Semi-Synthetic". I heard that synthetic oil has a tendency to leak, but do not feel this is the entire problem, as leakage is considerable. We plan to change back to a heavier conventional oil as soon as we can get the valve covers properly sealed.Any ideas on this? Thanks,Fred Link to comment Share on other sites More sharing options...
Larry Schramm Posted August 14, 2010 Share Posted August 14, 2010 I would use the new gray RTV that GM uses. I have used it with great success. It comes in a Loctite blister pack at the auto stores. Link to comment Share on other sites More sharing options...
Guest Posted August 14, 2010 Share Posted August 14, 2010 Fred, I always use cork gaskets. The pressure distribution tabs are a good idea, although in 45+ years of working on Pontiac's have never used them. I use aviation permatex on the valve cover side only and never get leaks this way. I did have a valve cover leak on my old 59 Catalina back in 1967 and that was because I used the rubber type and after the same struggles your having today I went back to cork. I would check the head surface and also the valve cover for warpage again.Don Link to comment Share on other sites More sharing options...
TexRiv_63 Posted August 16, 2010 Share Posted August 16, 2010 Fred,I have had better luck with the cork gaskets. The neoprene type likes to move around too much but it is better if you need to remove your valve covers on a regular basis. I have used Olson gaskets on my old cars, they supply a gasket that appears to be a rubberized cork? I glue the gasket to the valve cover with Permatex #2 or High-Tack, then I apply a coat of wheel bearing grease to the head side, this seals but still allows removal. Good luck! Link to comment Share on other sites More sharing options...
Bhigdog Posted August 16, 2010 Share Posted August 16, 2010 Cork is better!..............Bob Link to comment Share on other sites More sharing options...
Ben Bruce aka First Born Posted August 16, 2010 Share Posted August 16, 2010 Fred, I had a similar problem with the pushrod [side ] cover on my Buick. The "rubber" gasket was actually wicking oil through it. Used cork. No more leak. I purchased a roll of cork and cut my own to save time and $$. Ben Link to comment Share on other sites More sharing options...
Caddieman53 Posted August 17, 2010 Share Posted August 17, 2010 I agree with the rest Fred. I used the cork on my 53 several years ago now and have never leaked a drop.Paul Link to comment Share on other sites More sharing options...
Mark Shaw Posted August 20, 2010 Share Posted August 20, 2010 I use cork gaskets and stick-em to the head. When I remove the cover the gasket provides a lip that keeps the residual oil from making a mess of the engine. Link to comment Share on other sites More sharing options...
Guest Earl Posted August 20, 2010 Share Posted August 20, 2010 You can't get neoprene gaskets to work in player pianos either... And that stuff tends to shrink with age as well. It's good to know it doesn't work well in cars either! Link to comment Share on other sites More sharing options...
Fred Zwicker Posted August 26, 2010 Author Share Posted August 26, 2010 After 3 tries with the rubber valve cover gaskets, finally was able to obtain a set of cork gaskets (Fel-Pro brand, the same as the rubber ones). Using the same methods as used previously, installed the cork gaskets and had perfect results - NO leaks. I can't figure out why they even sell the rubber gaskets, although one friend who used to drag race liked the rubber gaskets as were easier to remove and replace for adjustments. I guess a little oil leak didn't bother him. Next is to remove the 5W30 oil semi-synthetic oil and replace it with 10W40 non-synthetic oil to quiet down some valve clatter at startup, which stops completely after warmup. I heard that synthetic oils tend to leak as well. This will be done tomorrow, as we are getting the car ready for the September 19th Glenmoor Concours show. See www.glenmoorgathering.comHere is a picture of the car.Fred Link to comment Share on other sites More sharing options...
Guest Posted August 26, 2010 Share Posted August 26, 2010 Fred, I'm glad everything turned out OK for you. Great looking Safari !!!Don Link to comment Share on other sites More sharing options...
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