Four stroke diesel engine | petrol vs diesel engine |चार स्ट्रोक इंजन कैसे काम करता है
Channel: G official
Date: 06/08/2021

Four stroke diesel engine 3D scene
Who to work diesel engine 

(SIMPLE ENGINE )
A simple reciprocating engine has a cylinder, a 
piston, a connecting rod, and a crankshaft. 

  ° FOUR STROKE ENGINE OPERATION
       A stroke is the movement of the piston from
TDC top dead center to BDC (bottom dead center,or from BDC to TDC. There are four strokes inone four stroke cycle of the engine. They are called 
the intake stroke, compression stroke, power stroke and exhaust stroke.

 1. #Intake Stroke : Gasoline will not burn unless it is mixed with the correct amount of air. It is very explosive when 1 part is mixed with about 15 parts of air. Shortly before the piston reaches 
TDC, the intake valve begins to open. As the 
crankshaft turns, it pulls the rod and piston 
down in the cylinder toward BDC This action creates a low-pressure void that is filled by atmospheric air pressure and fuel through the open intake valve. About 10,000 gal￾lons of air is drawn in for every 1 gallon of fuel supplied by the fuel system. The ideal mixture 
called stoichiometric for the combined purposes of engine performance, emission control, 
and fuel economy is about Older vehicles had carburetors and newer 
vehicles manufactured since the mid-1980s have 
fuel injection systems with computer controls. 
The computer monitors the oxygen content in 
the vehicle’s exhaust and then adjusts the fuel 
supply to provide the correct amount of fuel 
and air for each intake stroke.
 As the crankshaft continues to turn, the pis￾ton begins to move back up in the cylinder and 
the intake valve closes 

 2. #Compression Stroke. The piston moves up in the 
cylinder, compressing the air-fuel mixture. If you light a puddle of gasoline on fire in open air it does not produce power. If it is 
confined in a cylinder, however, usable power 
can be produced. Compressing the mixture of 
air and fuel into a smaller area makes it easier to 
burn. The compression stroke begins at BDC 
after the intake stroke is completed. As the piston moves toward TDC, both of the valves are 
closed as the mixture is compressed to about 
of the volume it occupied when the piston was 
at BDC. In this case, the compression ratio .

     3. #Power Stroke. As the piston approaches TDC on its compression stroke, the compressed air-fuel 
mixture becomes very explosive.
When the ignition system generates a spark at 
the spark plug, the fuel ignites. The air-fuel 
 mixture burns, but it must not explode. As the 
mixture burns it expands, forcing the piston to 
move down in the cylinder until it reaches BDC. The action of the piston turns the 
crankshaft to power the car. The power stroke is 
sometimes called the expansion stroke.
 Some leakage of gases past the rings occurs 
during the power stroke. This leakage, called 
blowby, causes pressure in the crankcase. 

   4.   #Exhaust Stroke. As the piston nears BDC on the 
power stroke, the exhaust valve opens, allowing 
the spent gases to escape. Because the burning 
gases are still expanding, they are forced outthrough the open exhaust valve. As the crankshaft continues to turn past BDC, the piston 
moves up in the cylinder, helping to push the 
remaining exhaust gases out through the open 
exhaust valve . A few degrees after 
the piston passes TDC, the exhaust valve closes. 
The entire four stroke cycle repeats itself, starting again as the piston moves down on the 
intake stroke.