How many degrees will the crankshaft rotate with both the intake and exhaust valves seated?

How many degrees will the crankshaft rotate with both the intake and exhaust valves seated?

• A. 180 degrees
• B. 245 degrees
• C. 350 degrees
• D. 360 degrees

Answer: (B)

The correct answer is that the crankshaft will rotate 360 degrees with both the intake and exhaust valves seated. This is because when both valves are closed, the engine is in the compression or power stroke, completing a full cycle of rotation. During this cycle, the crankshaft moves through all the positions necessary to allow for fuel intake, compression, power generation, and exhaust, thus resulting in a full rotation of 360 degrees. The options provided might suggest other measurements due to misunderstandings related to degrees of rotation during specific strokes, but in standard operation of a reciprocating engine, the complete cycle from one TDC (top dead center) through to TDC again involves a full 360 degrees of crankshaft rotation.

The correct answer is that the crankshaft will rotate 360 degrees with both the intake and exhaust valves seated. This is because when both valves are closed, the engine is in the compression or power stroke, completing a full cycle of rotation. During this cycle, the crankshaft moves through all the positions necessary to allow for fuel intake, compression, power generation, and exhaust, thus resulting in a full rotation of 360 degrees.

The options provided might suggest other measurements due to misunderstandings related to degrees of rotation during specific strokes, but in standard operation of a reciprocating engine, the complete cycle from one TDC (top dead center) through to TDC again involves a full 360 degrees of crankshaft rotation.