PERFORMANCE OF So I. ENGINES WITH DIESEL GASOLINE BLENDS

Abstract

With a view to assess the suitability of Diesel- Gasoline blends are fuel for spark ignition engines, the S.I. engine performance with various diesel • gasoline blends was studied on a B.A.S.F. variable compression ratio knock testing engine. tifferent percentages (up to 20%) of diesel - gasoline were tried to find its effect on the knocking tendency; power out put; thermal efficiency; specific fuel consumption; octane number rating and smoke density under various engine operating conditions. Using Ricardo's method of knock rating it was found that the highest useful compression ratio decreases as the percentage of diosel increases. At 900 rpm it decreases from 5.10 (gasoline only) to 4.20 (20% diesel). Out put of the engine increases with the increase of diesel content in petrol. Increase in out put is found to be about 50% with 20% diesel. Specific fuel consumption decreases with increase of diesel up to a certain limit and then it increases. The most economical blend was found to be 15% diesel«» gasoline blend, at this thermal efficiency is the maximum and specific fuel consumption minimum. Octane number for all blends is found out by using Research Method. IN also decreases with the increase of diesel content in the gasoline. For gasoline AON obtained is 76.866 and It ii decreases to 72.10 with 2b% diesel. Efforts have been made to find the relative value of exhaust density using a cadmium sulphide photocell.