Great price (compare with anyone on the internet).
5/16 x .500 Black Carbon Viton Seals with full metal jacket. While all Viton valve seals offer superior resistance to heat, oil additives and abrasion, black carbon seals offer the highest levels of resistance. Viton valve seals improve the efficiency and performance of your engine by preventing engine oil from entering the combustion chamber. The full metal jacket, which prevents swelling due to oil retension, increases the seals long-term durability and service life.
Machining may be required, however we recommend these seals for two reasons. First, the smaller diameter of the seal increases the valve spring clearance (distance between the outer surface of the seal and the inner surface of the valve spring). This may be required when using a single spring with a damper, or with dual springs. Secondly, machining the valve guide (which is done with a valve guide cutter), and press fitting the seal, prevents the seal from sliding upwards even after the seal drys out and/or hardens over it's service life. Note the small groove which is machined into the guide during the process, which helps to ensure that the seal will stay where it belongs, long after other seals have failed.
These seals can be used with stock or high performance single springs, single springs w/dampers, or dual springs.
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| Cut Valve Guide with Groove. |
