THE EFFECT OF LIGHT DIESEL OIL ON HIGH SPEED DIESEL ENGINES

Abstract

The investigation aims at determining the consequences and advisability of running high speed diesel engines on light diesel oil instead of high speed diesel oil as recommended by  and according to, makers'specifications. For experimental work three high speed diesel engines are chosen which are identical in every respect except for the combustion chambers and the compression ratio. Two of them have precombustion chambers and a compression ratio of 19: 1, and the third has an open combustion chamber and a compression ratio of 1675: I. All of them have the same bore and stroke and are rated to develop 5 B.H.P. at 1,500 R.P.M. These engines are run under identical test conditions but on two different fuels One precombustion chamber engine is run on high speed diesel oil for 2,000 hours and the other is run on light diesel oil for 2,000 hours. The open combustion chamber engine is also run on light diesel oil for 1,500 hours. Both precombustion chamber engines are fitted with plain cast iron top compression rings during the first 1,000 hours of test and chromium plated top compression rings during the second 1,000 hours of test. The third engine is fitted with a chromium plated top ring throughout the test.Results show clearly that it is not advisable to run high speed diesel engines of customary design on light diesel oil since in the long run this leads to increased wear, ring sticking, valve burning and pitting of valve seats. In an emergency, however, light diesel oil can be used for short periods without adverse effects. The wear of the engines running on either of these fuels is appreciably  reduced when fitted with chromium plated top compression rings instead of plain cast iron rings.