A Comparison of the Wear of Small Gasoline and Diesel Laboratory Engines

Abstract

Differences in the top compression-ring wear characteristics of two single-cylinder engines are presented. Wear determinations were made using the radioactive tracer technique. It was found that a high-speed, 19/1 compression ratio (C.R.), indirect-injection diesel-engine displayed generally more severe wear than did a 5/1 C.R. gasoline engine and experiments made to investigate the observed differences are described. As part of these experiments the diesel engine was extensively modified to enable it to be run as a spark-ignition engine under comparable conditions to the gasoline engine.

Comparative wear data are given for the two engine types under various controlled running conditions. The main test variables were: load, cooling-jacket temperature, fuel type and fuel sulphur content.

Analysis and discussion of the results is based on general considerations of corrosive and abrasive conditions prevailing in the cylinders as influenced by the combustion process.