A six-cylinder SI engine with a compression ratio of 10.5:1 operates on a four-stroke cycle at 3000 RPM. Air enters the cylinders at and psia. The intake valve closes at 20° aBDC and combustion starts...

A six-cylinder SI engine with a compression ratio of 10.5:1 operates on a four-stroke cycle at 3000 RPM. Air enters the cylinders at and psia. The intake valve closes at 20° aBDC and combustion starts when the spark plug fires at 15° bTDC. Connecting rod length is 6.64 in. and crank offset is 1.66 in.

Calculate:

(a) Cylinder temperature at start of combustion using air-standard Otto cycle analysis. [°F]

(b) Cylinder temperature when spark plug fires assuming compression doesn’t start until intake valve closes. [°F]