Construction and design assures long service. The cups are molded from tough, durable tread rubber, while the one piece handle is made of a material resistant to the grease and corrosives normally associated with gasoline engine repair. The three sizes of cups provided in this set cover most small engine and automotive valves. Lapping is the most effective means of touching up slightly burned valves and seats, to restore like-new performance at minimum expense. Even after grinding, a slight lapping operation may be desirable.
Modern valve refacing and reseating methods bring sealing surfaces into nearly full contact.
However, slight irregularities, caused by vibration of equipment used over a long period, make this extra lapping step the best way to be certain of a perfect job. The perfect tool for lapping must hold the valve firmly, flex without popping off, spin easily between the mechanic's hands and lift without losing its grip. The Powr-Grip Valve Grinder does all these. Handle size and shape, and cup flexibility provide optimum ease and efficiency in spinning and lifting the valve. After the final cleaning of compound from the valve, we recommend a few turns with oil to lift the remaining compound from the pores of the metal and to allow more accurate clearance adjustments.