30-20 Knowledge Check

Front

Which of the following is an example of a Spark Ignition / Gasoline (Four-Stroke) engine application in the Navy and Marine Corps? San Antonio Class LPD, Lawnmower, MRAP, Seabee Excavator

Back

Lawnmower

Front

Which of the following vehicles is NOT listed as using a Compression Ignition / Diesel (Four-Stroke) engine in the provided material? MRAP, HMMWV & LCU, Amphibious Combat Vehicle, Piper Warrior II

Back

Piper Warrior II

Front

Which of the following is a reason why diesel engines are more prevalent in the Navy and Marine Corps compared to gasoline engines?
Options:
1. Diesel engines are less fuel efficient than gasoline engines.
2. Diesel fuel is less volatile, making it safer to store and transport in a warzone.
3. Diesel engines have a higher top speed than gasoline engines.
4. Diesel engines are lighter than gasoline engines.

Back

Diesel fuel is less volatile, making it safer to store and transport in a warzone.

Front

Explain why the Navy and Marine Corps might choose diesel engines over gasoline engines for vehicles used in challenging terrain or for pulling heavy loads.

Back

Diesel engines provide more torque at low engine speed, which is beneficial for traversing challenging terrain or pulling heavy loads.

Front

What is the main difference between a compression ignition engine and a spark ignition engine?

Back

Compression ignition engines combust fuel by injecting it into high temperature air, while spark ignition engines use a spark plug to ignite the fuel.

Front

Where is the piston located when the volume of air in the cylinder is the largest?

Back

At Bottom Dead Center (BDC)

Front

Why are reduction gears used in vehicles and ships with crankshafts?

Back

To reduce the speed of the crankshaft to the needed speed of the wheels or propeller

Front

Based on the diagram, what happens when the lobe of the cam pushes the cam follower?

Back

The rocker arm is pressed, opening the valve

Front

Which valve is open during the intake stroke of a four-stroke spark ignition engine?

Back

Intake valve

Front

What is the primary function of a fuel injection system in an automotive engine?

Back

To mix fuel with air to produce a combustible mixture