The Strokes
During this stroke, the piston moves downward while the intake valve is open, creating space for the air/fuel mixture.
What is the Intake Stroke?
what Moves Up and Down inside the cylinder, receives force created by combustion, and transfer that force to the connecting rod?
What is the piston?
this components job is to keep unwanted dirt and debris from entering the engine with the incoming air.
What is the air filter?
The piston must be able to move so combustion can transfer force into mechanical motion.
put these four strokes in order, starting with the stroke where fresh air/fuel charge enters the cylinder.
intake, compression, power, exhaust
The purpose of this stroke is to increase pressure while both valves are closed.
What is Compression?
The link between to very different types of motion. one end follows a piston moving up and down, while the other applies force to an offset point on a rotation component.
What is the connecting rod?
This component must seal the cylinder during compression and power.
What is a Valve?
An engine completes the intake stroke, but the intake valve never closes. What important part of the next stroke will be affected, and why?
compression, because the cylinder cannot properly seal the mixture.
Put these events in order.
piston moves downward, air/fuel enters the cylinder, intake valve opens, intake valve closes
intake valve opens, piston moves downward, air/fuel enters the cylinder, intake valve closes.
The Piston moves downwards even though neither valve is open. What event must have occurred immediately before this downward movement?
What is the Combustion?
What is the crankshaft?
This is what the power stroke ultimately does: transfer the force of combustion into movement of the piston.
What is mechanical work?
the source of the downward force is driven by expanding gasses while intake is driven by the piston creating space for the incoming charge.
Put these events in the correct order as an air/fuel mix moves through the engine and becomes useful mechanical motion.
A. combustion creates expanding gas
B. air/fuel enters the cylinder
C. piston is forced down
D. mixture is compressed
E. spark ignites mix
F. connecting rod transfers force to the crank
B, D, E, A, C, F
A student observes the piston moving upward and sees the exhaust valve open. The intake valve remains closed. What is the engine accomplishing, and why is the piston moveing upward?
What is the Exhaust Stroke pushing burned gasses out of the cylinder?
This part rotates half the speed of the crankshaft.
What is the camshaft?
My job is to move a fresh charge into the cylinder so that the engine has the material needed for combustion.
What is the Intake Process/Stroke?
An engine has air, fuel, compression, and spark. however, the spark occurs while the piston is still moving upwards during the compression stroke. why would the engine fail to produce a normal power stroke?
combustion is occurring at the wrong point in the cycle, so the expanding gasses are not being used effectively to drive the piston downward.
A. crankshaft recieves turning force
B. mixture is compressed
C. spark occures
D. cylinder pressure rapidly increases
E. piston begines moving downward
F. combustion spreads through the mixture
B, C, F, D, E, A
A piston is moving upward with both valves closed. The air/fuel mix is being squeezed, but combustion has not happened yet. The piston reaches the top of its travel. what stroke is ocuring and what must happen next to begin producing the power stroke?
What is the Compression Stroke, followed by ignition of the compressed mixture?
This part remains inactive while the cylinder is being filled and the mix is being compressed. Near the end of the upward stroke, this part starts an event that causes rapid pressure increase.
What is the spark plug?
My job is to convert a force acting in a straight line into a twisting force that can rotate a shaft.
What is Torque?
an engines piston moves normally through all four strokes, the valves operate correctly, and the air/fuel mix ignites. however, the crankshaft remains stationary. what does this tell you about where the problem must be in the engines energy transfer path?
the problem must be between the pistons combustion force and the crankshafts rotation
Put these events in order, starting with a compressed mixture.
A. crankshaft rotates
B. Combustion expands gas
C. Connecting rod transfers force
D. piston moves downward
B, C, E, D, A