Patent ID: 6962643

Claim:
A method of sealing a rocker cover to a cylinder block comprising: applying to a flange portion of said rocker cover a composition comprising: (A) an organopolysiloxane having at least two silicon atom-bonded alkenyl groups per molecule; (B) an organohydrogen polysiloxane having at least two silicon atom-bonded hydrogen atoms per molecule; (C) 10 to 30 parts by weight of fumed silica with respect to a total of 100 parts by weight of said component (A) and component (B); and (D) 50 to 100 parts by weight of an inorganic filler selected from the group consisting of calcium carbonate, magnesium carbonate and quartz powder with respect to a total of 100 parts by weight of said component (A) and component (B), curing said sealing agent to a hardness of 60 to 80 as measured with a type A durometer according to JIS K 6253, and compressing said sealing agent between said rocker cover and said cylinder block at a compression of 20 to 40%.