New Methods in VALVE CAM DESIGN

Abstract

<div class="htmlview paragraph"><b>B</b>Y relatively simple mathematics, it is possible to include the effects of mass, flexibility, valve-spring force, and gas pressure in designing valve cams for automobile or aircraft engines.</div> <div class="htmlview paragraph">First, a curve of ideal valve motion having suitable lift area and minimum acceleration properties is specified. Then, with the valve assumed to be executing this motion at a chosen speed, the sum of the inertia, gas pressure, and valve-spring forces can be computed at any point in the cycle. The driving force to overcome these resistances is created by compressing the valve linkage.</div> <div class="htmlview paragraph">The amount of deflection needed at any time can be found. These deflections are added to the valve motion to find the correct cam lift.</div>