Air-Cooling Effects of Fins on a Motorcycle Engine (3rd Report, Influence of Residual Heat between the Fins)

Abstract

This is a study of the effect of residual heat between fins of air-cooled cylinders. The object of the study is to find out what portion of cylinders should be cooled in order to achieve the optimum air-cooling effect and uniform cooling of fins. Aluminum-alloy cylinders with trapezoidal fins were made and used as experimental cylinders. Five cylinders were made with different pitches of fins and the maximum number of fins was installed. A dedicated testing system, mainly composed of a blower, a differential pressure gauge, a data logger and a test section, was also made. The ventilation speeds were 0,20,40and 60km/h. Thin thermocouples were installed between the fins of sample cylinders and local temperatures were measured at 30 points.