Thread: a question from my auto exam

suck, sqeeze, bang, blow?

is that it?......

Chris

Intake, compression, power, exhaust.....



But suck, squeez, bang, blow, sounds better.

Andrew

'93tdi200 disco
'65 88" s2a

Starting at TDC (assuming a single cylinder over head valve configuration)

With both valves on the rock, inlet opening exhaust closing the next downward movement of the cylinder is called the induction stroke which is achieved initially via an external force applied to the crankshaft to initiat rotation and once the OTTO cycle is established under inertia gained during the power stroke. The inlet valve opens rapidly and at the bottom of this stroke the inlet valve closes and piston begins to move up the cylinder. At this point a fuel/air charge (in the case of a petrol) has been administered to the cylinder and is ready for compression (in the case of a diesel its only air)

The next stroke is the compression stroke there is no valve movement on this stroke of the cylinder and the piston is forced up via the rotation of the crankshaft via an externally applied force or under the inertia of itself, the flywheel and any other rotating mass attached. Near the top of this stroke the spark plug is fed a high voltage from the ignition system which arcs across the airgap and commences combustion The piston is still moving upwards when this occours. In the case of a Diesel the compression is sufficient to raise the air temperature above the flash point of the fuel that is injected in atomised form into the combustion chamber. This injection occours at about the same timing as the spark in a petrol engine.

Once the crank rotates past TDC with both valves closed the power stroke (assuming the combustion process has occurred and is self sustaining) the power stroke has begun which takes advantage of the adiabatic process where a rise in temperature gives a rise in pressure, The rise in pressure exerts force on the crown of the piston and in following with the isobaric rules for thermal reactions pushes the piston down (AKA nature abhors a vacuum) As the piston approaches bottom dead center the exhuast valve begins to open and the residual energy of the combustion process begins the process of evacuating the combustion area.

Once the cylinder has passed bottom dead center and is rising again the exhaust valve rapidly opens and the piston again under inertia or external force applied to the crank shaft rises and expels the remaining gases. Near the top of this stroke the exhaust valve begins to close and the inlet valve begins to open in preperation for the cycle to begin again. This forth and final stroke is called the exhaust stroke.


Is that close enough or do you want an indepth answer?

Originally Posted by Blknight.aus

Starting at TDC (assuming a single cylinder over head valve configuration)

With both valves on the rock, inlet opening exhaust closing the next downward movement of the cylinder is called the induction stroke which is achieved initially via an external force applied to the crankshaft to initiat rotation and once the OTTO cycle is established under inertia gained during the power stroke. The inlet valve opens rapidly and at the bottom of this stroke the inlet valve closes and piston begins to move up the cylinder. At this point a fuel/air charge (in the case of a petrol) has been administered to the cylinder and is ready for compression (in the case of a diesel its only air)

The next stroke is the compression stroke there is no valve movement on this stroke of the cylinder and the piston is forced up via the rotation of the crankshaft via an externally applied force or under the inertia of itself, the flywheel and any other rotating mass attached. Near the top of this stroke the spark plug is fed a high voltage from the ignition system which arcs across the airgap and commences combustion The piston is still moving upwards when this occours. In the case of a Diesel the compression is sufficient to raise the air temperature above the flash point of the fuel that is injected in atomised form into the combustion chamber. This injection occours at about the same timing as the spark in a petrol engine.

Once the crank rotates past TDC with both valves closed the power stroke (assuming the combustion process has occurred and is self sustaining) the power stroke has begun which takes advantage of the adiabatic process where a rise in temperature gives a rise in pressure, The rise in pressure exerts force on the crown of the piston and in following with the isobaric rules for thermal reactions pushes the piston down (AKA nature abhors a vacuum) As the piston approaches bottom dead center the exhuast valve begins to open and the residual energy of the combustion process begins the process of evacuating the combustion area.

Once the cylinder has passed bottom dead center and is rising again the exhaust valve rapidly opens and the piston again under inertia or external force applied to the crank shaft rises and expels the remaining gases. Near the top of this stroke the exhaust valve begins to close and the inlet valve begins to open in preperation for the cycle to begin again. This forth and final stroke is called the exhaust stroke.


Is that close enough or do you want an indepth answer?

Dave I think you may have just a little to much spare time.... very good
answer though

Ben.....

good answers another question was name 2 advantages that a 2-stroke engine has over a 4-stroke engine once u guys tell me your answers ill tell you mine just in case im wrong

Originally Posted by schmierer LR at singleton

good answers another question was name 2 advantages that a 2-stroke engine has over a 4-stroke engine once u guys tell me your answers ill tell you mine just in case im wrong

No need for a sump or reserve of oil/engine lubricant

Able to run at higher revs

Also, they are lighter due to less moving parts

Twice as many power strokes per revolution

Fewer moving parts.

John

Originally Posted by AKW

Intake, compression, power, exhaust.....



But suck, squeez, bang, blow, sounds better.

Andrew

'93tdi200 disco
'65 88" s2a

the top one is right
the bottom is wat we use to use ase a description
(tafe courses)