Question 1. A two-cylinder, four-stroke gas engine has a bore of 350 mm and a stroke of 575 mm. At 250 rpm, the torque developed is 5.0 kNm. The air/fuel ratio is 7:1 by volume. The estimated volumetric efficiency is 85% and the calorific value of the coal gas is 16,800 kJ/m³. Calculate (a) the bp, (b) the mean piston speed, (c) the bmep and (d) the brake thermal efficiency of the engine.