for an ideal otto engine operating on air standard, the temperature at the end of isentropic compression is 840 F (449 C) and at the end of expansion is 2540 F (1393 C). the compression ratio is 7.5....

for an ideal otto engine operating on air standard, the temperature at the end of isentropic compression is 840 F (449 C) and at the end of expansion is 2540 F (1393 C). the compression ratio is 7.5. find the work, Btu/lb or kJ/kg and thermal efficiency.