1. spark plug
   carburetor
2. battery

Sure, this is a pretty simplistic explanation, but basically,​ a spark plug ignites the oxygen and gas mixture to make energy for the engine. Engine experts just call these "plugs," but they are often called "sparking plugs" in the U.K.

1. intake
   compression
2. funneling

Funneling is not a function of a combustion, or four-stroke, engine. The strokes are intake, compression, combustion, and exhaust.

1. gas tank
   muffler
2. intake valve

The intake valve allows fuel to enter the combustion chamber. In the combustion chamber, gas and air combine and are combusted (see how much sense these parts make?).

1. rider valve
   exhaust valve
2. seat valve

The exhaust valve moves engine waste products out of the engine via the exhaust pipe. Waste materials in a combustion engine include fuel that has been burned off.

1. true
   false
2. who knows

This is false. A jet engine, just like a car engine, is an internal combustion engine, but on a much larger scale.

1. wheel
   battery
2. piston

Pistons pump up and down to power the engine. Pistons are typically cylindrical​ and move power to a rod that, through a series of mechanisms, moves the wheels.

1. bubble gum
   duct tape
2. piston rings

Piston rings are used to seal the piston heads. The purpose of the seal is to prevent gas from getting into the crank case.

1. 1,000 miles
   3,000 miles
2. 50,000 miles

Most oil manufacturers recommend that you change your car's oil every 3,000 miles. However, you should always follow your car manufacturer's recommendations about when to service your engine.

1. growl
   Intake
2. exhaust

Stephen King might be able to make a car growl, but growling is not a function of today's combustion engine. The four functions of a four-stroke engine are intake, compression, combustion, and exhaust.

1. battery
   radiator
2. crankshaft

The crankshaft rotates to help move the wheels of the car. Think of this as a sort of handle that turns to produce movement or power.

1. muffler
   battery
2. piston rod

The piston rod connects the piston to the crankshaft. The crankshaft turns to move power to the wheels.

1. it releases coolant
   it burns up
2. it turns blue

If an engine gets too hot, it can burn up. The fluids in your car's engine help keep it from getting too hot.

1. muffler engine
   four-stroke engine
2. wheelie engine

Today's common combustion engine is a four-stroke engine. The strokes are intake, compression, combustion, and exhaust.

1. fill up
   compression
2. combustion

Fill up is not a function of a four-stroke engine. The four functions are intake, compression, combustion, and exhaust.

1. because combustion takes place outside the engine
   because combustion takes place underneath the engine
2. because combustion takes place inside the engine

Today's car engines are called internal combustion engines because the combustion that powers the car takes place inside the engine. Yes, there are such things as external combustion engines - like a steam engine.

1. heat
   glass
2. cold

Today's internal combustion engine uses heat to make power. The magic takes place in a combustion chamber.

1. true
   false
2. who knows

This is false. A car engine can have more than eight cylinders. In fact, it's rare, but a car engine can have even more than 20 cylinders.

1. true
   false
2. who knows

This is false. A rocket engine is an internal combustion engine that functions in much the same way as a car engine.

1. four cylinders on top of six cylinders
   four cylinders that are shaped like Vs that last six months
2. six cylinders in a V shape

V6 engines are referred to as such because there are six cylinders displayed in a V pattern. This pattern helps reduce the size of the engine.

1. ground
   water
2. fossil

Internal combustion engines are typically powered by fossil fuels. Fossil fuels include fuels such as gasoline and diesel.

1. water mixing
   battery power
2. expanding molecules

Burning gasoline causes heat in internal combustion engines because the molecules in the gasoline expand and get hot. Gasoline molecules include hydrogen and carbon.

1. crankshafts
   color
2. power

Pistons equal power in the modern car engine. The more pistons an engine has, the more powerful it is.

1. air filter
   grate
2. seive

A car engine uses a simple air filter to make sure that dirt and dust don't get into the engine. The air is necessary to help ignite the fuel in the engine.

1. from the air in space
   from planet Mars
2. from storage tanks

Space rockets carry oxygen in storage tanks on the ship. There is no air in space.

1. to light on fire
   to store helium
2. to push the gas pedal

Ignition is the process of setting something on fire. When you turn the ignition key of your car or when a space rocket has ignition, that means the engine has ignited the fuel.

1. radiator
   air conditioner
2. brakes

A car's radiator helps keep the engine cool. The radiator uses a coolant to keep things cool. The exhaust system also helps keep the engine cool by moving used fuel out of the engine.

1. wood doesn't burn
   coal doesn't burn
2. we would need too much

We actually could use wood or coal to power a car's engine, but that would be an external combustion engine, like a steam engine. External combustion engines tend to be large and inefficient. Today's internal combustion engines use fuel that is more efficient so the engines are smaller.

1. combustion
   wheelies
2. exhaust

Although you may be able to do a wheelie with your car, wheelies are not a function of the engine. The four functions of a four-stroke combustion engine are intake, compression, combustion, and exhaust.

1. the battery
   the oil pan
2. the radiator

The oil pan sits at the bottom of the pump. The job of the oil pan is to collect oil.

1. straight
   inline
2. both a and b

Four-cylinder​ engines are typically straight or inline - two names for the same configuration. Engines with six to eight cylinders are displayed in a V shape.

1. butter
   vaseline
2. oil

Motor oil, or just oil, is used to lubricate the engine parts. Without motor oil, your car's engine will cease to function.

1. flywheel
   brake
2. battery

The flywheel keeps the engine from vibrating too much. Combustion causes vibration, but the flywheel balances the engine so it does not vibrate too much.

1. straignt
   flat
2. crowded

Crowded is not a type of cylinder arrangement. Typical arrangements include the V shape, straight or inline, or flat, although flat arrangements are less common.

1. muffler
   radiator
2. rotary

A rotary engine does not have pistons. A rotary engine is an early type of combustion engine that did not have a moving crankshaft, and therefore, had no need for pistons.

1. growover
   rumble
2. exhaust

From start to finish, the four functions of a four-stroke engine are intake, compression, combustion, and exhaust. These are the functions of today's combustion engine.