Tappet adjustment for overhead valve engine - involves distance piece set into slot in base of tappet sleeve

摘要

A tappet sleeve over the end of the valve stem is worked by a cam immediately above it. A recess in the base of the sleeve holds a distance piece of the same shape as the recess. The clearance is varied by replacement of the distance piece by another piece of different thickness. The shape of the distance piece and recess is such that the piece is held from turning or sliding, and there is a threaded hole through the cam and when a stud is screwed through this it presses through a hole in the tappet sleeve and depresses the distance piece so that it can be turned and slipped out through an opening in the side of the sleeve.