1 : The scavenging efficiency and the scavenging ratio of a loop scavenged two-stroke engine are80% and 0.9 respectively. Determine trapping efficiency of the engine. If the trapping efficiency is increased by 10%, determine the percentage decrease in scavenging ratio. Assume that the scavenging efficiency remains constant.

2: A two stroke single cylinder SI engine consumes 6.5kg/h of fuel when running at 3000rpm. The air/fuel ratio is 15:1; calorific value of fuel is 44000 KJ/kg. The mean piston speed is 9m/s and indicated mean effective pressure is 4.8bar. The scavenging efficiency of the engine is 85% ;mechanical efficiency is 80%. Determine the bore, the stroke, the brake horse power and brake thermal efficiency of the engine. Take R=290 J/kgK. The pressure and temperature of the mixture are 1.03bar and 15 o C. Assume perfect displacement model.