How does a four stroke engine work?

How does a four stroke engine work?
the four strokes are:
-Intake
-compression
-power/combustion
-exhaust
Each of these have one full stroke of the piston and a completed cycles is 2 revolutions of the crankshaft.

Name cycles and what the piston is doing and the valves on each stroke.

For Intake the piston moves down getting an intake of a air/fuel mixture the exhaust valve is held shut.

Compression: As the flywheel pushes the piston up the the poppet valve shuts from the pressure of the cylinder. both valves are closed

power/combustion : Spark plug ingites the compressed fuel and when the fuel is burning it drives the piston downwards. both valves are closed.

Exhaust : the piston travels to TDC intake valve is closed and exhaust valve closed/

Who and what year was the four stroke engine invented?

Invented in 1876 by Nikolaus Otto

What is the purpose of the crankshaft?

its the up and down movement of the pistons which converts to a rotational movement of the crankshaft

 



camshaft: the camshaft is connected to the crankshaft by the timing belt. It controls the inlet, outlet valves and the air/fuel mixture

Valve collets: They work in pairs and hold the exhaust and inlet valves in the engine.

Valve stem seals:  It controls the amount of oil that goes to the valves and the combustion chamber for the lubrication.

Head gasket: The head gasket sits between the block and head of the engine. It creates the full compression needed and prevents leaks from either oil or cooland into the cylinders. 

Piston: they are attached to the crankshaft by the con rods and create compression of the air/fuel mixture that will ignite then the force from that turns the crankshaft.

Piston rings: these are the open ended rings around the pistion that seal the combustion chamber. they also transfer head from the piston to the cylinders wall and control the oil consumption.
 

 


Cambelt: controls the timing of the engines valves.

Flywheel: Keeps the crankshaft tunring from the energy that is made by the power stroke.

What is the bore and the stroke?
- the bore is the diameter of the chamber
- stroke is when the piston moves up and down the combustion chamber from TDC to BDC