Valve Seals
To minimise the risk of combustion gases passing between the valve stem and guide, the valve seals have double sealing lips, which act as check valves. In addition to sealing off gases from the combustion chamber, the seal must also allow oil through to lubricate the valve stem. The exhaust valves need more lubrication compared to the intake valves. The valve seals are therefore available in two variants. The seals on the inlet valves are brown. The seals on the exhaust valves are green.