Permatex 82180 Ultra Black Maximum Oil Resistance RTV Silicone Gasket Maker
If you need a sealant for engines, especially one in which the sealant is going to come into contact with oil, this one's for you. Drawn from Permatex's extensive line of automotive sealants, this is one of their "ultra" line, a series of sealants designed for extreme applications. This sealant has the highest resistance to oil and other automotive chemicals you can find. In addition, it's fast drying, so you can get your engine back together quickly. Retains high flexibility, even at high temperatures. While this isn't a high temperature sealant, it can withstand temperatures up to 500 degrees.