In order to find out optimum compression ratio expert ments were carried out on a single cylinder four stroke variable compression ratio diesel engine. Tests were carried out at compression ratios of 13.2,13.9,14.8,15.7,16.9,18.1 and 20.2. Results showed a significant improved performance and emission characteristics at a compression ratio 14.8. The compression ratios lesser than 14.8 and greater than 14.8 showed a drop in break thermal efficiency, rise in fuel consumption along with increased smoke densities.

 

Keywords: engine, diesel, compression, ratio, performance, smoke, density.