I recommend using RTV, aka silicone sealant, in place of a gasket whenever possible. I worked at the Ford prototype engine build and dynamometer facility from 1978 to 1985. During that time we worked with all the major gasket and sealant suppliers looking for better, mostly cheaper, ways to keep fluids in and dirt out. RTV was the easy winner for diff covers, oil pans, valve covers, timing chain covers, etc.
Most important is to make sure both sealing surfaces are chemically clean. Use brake cleaner, acetone, etc., anything that does not leave a film when it dries will work. If resealing an old RTV joint, you must make sure all the old RTV is removed. New TRV simply will not adhere to old RTV.
The best proof I know is a 650 Triumph I built using RTV in place of every gasket except the copper head gasket. The only place it leaked oil was from the trans output shaft and that was after about 60,000 miles in three years. Considering how Limey machines usually leak, I acknowledged the leak as an automatic chain oiler and let it go at that.
Mike in Michigan
The exception to using RTV is for applications where you will be removing the cover, as in valve covers over mechanical lifters. At the dyno lab, we had to pull valve covers every 25 hours to check valve lash, guide wear, etc. A trick we used to glue cork gaskets to the cover with contact cement and spread a thin coat of grease on the gasket so it would not bond with the cylinder head. We often got 300 hours or about 10 removals out of one set of gaskets. If the gasket was damaged during removal, the gasket was mostly stuck to the cover and easier to scrape off than the heads. This also minimized the chance of getting chunks of old gasket lost in the crankcase where they might clog the oil pickup screen.
1 - 5 of 5 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.