Engine Mechanics Quiz

The amount of throw (offset) built into the _____ rod journals controls the piston stroke.

• transmission input shaft

• crankshaft

• balancer shaft

• camshaft

True or False? Generally, a larger bore and a longer stroke make an engine more powerful.

• True

• False

Piston displacement is the volume the piston moves as it travels from _____.

• the center of the cylinder to bottom dead center (BDC)

• bottom dead center (BDC) to top dead center (TDC)

• the engine oil sump to top dead center (TDC)

• None of the above.

Compression pressure is normally measured in ____.

• cubic yards

• watts or joules

• newtons

• pounds per square inch or kilopascals

What is used to measure engine or cylinder pressure while cranking the engine?

• Vacuum gauge.

• Pyrometer.

• Compression gauge.

• Dial indicator.

What is the normal compression pressure for a modern automotive gasoline engine?

• 75–100 psi.

• 130–180 psi.

• 180–200 psi.

• 200–250 psi.

All of the following are possible causes if an engine’s compression pressure is low except ____.

• clogged engine oil passages

• burned valves

• blown head gasket

• bad piston rings

What accounts for most of an engine’s frictional loss?

• The friction between the pistons, rings, and cylinder walls.

• The release of exhaust gases from the engine cylinders.

• The vibration of the balancer shaft(s).

• The hydraulic pressure leakage in the engine’s cam followers.

If a hydraulic lift raises a 3,395 lb car 5.5’ in 15 seconds, how much power is needed?

Define compression ratio.