:: ENGINE PROBLEM ::

Synchro-seating is a description used when stoning valve seats. The stones are faced in the arbor they are mounted on. The use of the correct pilot grinds the seat concentric to the guide. The throating angle was ground by changing stones and the top angle required another stone change. This method required a high degree of skill, was dirty and time consuming. The preferred method today is machining the three angles (top ,seat and throat) in on operation with a multi-angle cutter and specialised machine. The only use for a synchro seating stone in modern workshops is for polishing difficult seats after machining.