Question 1: Similarly, overhead cams and multiple valves per
cylinder were introduced, while automobile engines continued to use
________ and didn't widely use more than
two valves per cylinder until the 1990s.
Question 9: The power of an internal
combustion reciprocating or turbine aircraft engine is rated in units of
power delivered to the propeller (typically horsepower) which is torque multiplied by ________ revolutions per minute (RPM).