PISTON CROWNS ARE NORMALLY CONCAVE IN SHAPE. THEY ARE NEVER MADE FLAT. THE REASON BEHIND THIS IS THAT, DUE TO AS THE GAS PRESSURE INCREASES AND DECREASES, THE FLAT PISTON CROWN WILL BECOME CONCAVE AND THAT TOO UNSYMMETRICALLY LEADING TO CYCLIC STRESS ON THE PISTON. THIS CAUSES FATIGUE ON PISTON AND PISTON MAY FAIL.
One response to “WHY PISTON CROWN OF A/E AND M/E IS NOT FLAT”
The piston crown is normally made concave and the cylinder cover lower face is made convex so that a larger volume is formed in the combustion space. This increases the intake of combustion air and hence fuel to be burned.