Based on your measurements so far, if the mechanical efficiency of the lawnmower engine is 0.50, what is the power output of the lawnmower engine, in kW, when it is operating at 2.50 x 10³ RPM with a mass air-to fuel ratio of 15 (kg air)/(kg fuel) with a fuel that gives 45,500 kJ/kg of energy?

Refer to a 3.5 horsepower lawn mower engine at a nominal speed of 2.50 × 10³ RPM. A typical lawn mower engine, and the inside of its cylinder head, is shown below. Note: the depression in the cylinder head is the clearance for the engine’s valves. If such an engine is available to you in class, you can disassemble it and measure the bore, stroke, and clearance volume, CV, of the engine.

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Valve clearances Piston Valves Fully assembled engine Partially disassembled engine