Which of the following will decrease volumetric efficiency in a reciprocating engine? 1. full throttle operation. 2. low cylinder head temperatures. 3. improper valve timing. 4. sharp bends in the induction system. 5. high carburetor air temperatures.

options 3,4,5 are the currect options

Explanation:

Volumetric efficiency in a reciprocating engine is defined as the ratio of the mass density of the air-fuel mixture drawn into the cylinder at atmospheric pressure (during the intake stroke) to the mass density of the same volume of air in the intake manifold.

Volumetric efficiency of  a reciprocating engine is decreased by

- improper valve timing

-sharp bends in the induction system

- high carburetor air temperature.

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