EFFECT of high speeds on valve gear, and the relationship of wear problems to design, is the subject of this paper. As automobile speeds increase, sensitivity of overhead valve parts increases, due to their flexibility and weight. Stiffness requirements and cam design are considered in relation to the dynamics of the system at high speed.
Another critical factor is encountered in the wear of tappet faces. The author reviews the large number of variables that play a part in tappet wear. He cites definite steps which have been taken to improve the situation, particularly in regard to the alignment of tappets. He states that the self-aligning tappet offers a new and encouraging approach to this problem.
Discussion of this and other papers on “Valve-Gear Problems in Modern Overhead-Valve Engines” starts on page 714.