Question

Given the following events in the table below and knowing that they are provided for a four stroke, spark-ignition engine running at 2500 RPM, please fill out the missing information.

Note that: BTDC=before top dead center, ATDC=after top dead center, ABDC=after bottom dead center, BBDC= before bottom dead center.

Process	Event	Duration (crank angle)	Duration(ms)
Intake	15 ˚BTDC to 60 ˚ABDC
Compression	BDC to 30 ˚BTDC
Combustion	30 ˚BTDC to 30 ˚ATDC
Expansion	TDC to BDC
Exhaust	60 ˚BBDC to 20 ˚ATDC
One engine cycle

Answer 1

Process	Event	Duration (crank angle)	Duration(ms)
Intake	15 ˚BTDC to 60 ˚ABDC	225	15
Compression	BDC to 30 ˚BTDC	150	10
Combustion	30 ˚BTDC to 30 ˚ATDC	60	4
Expansion	TDC to BDC	180	12
Exhaust	60 ˚BBDC to 20 ˚ATDC	260	17.33

a 4 stroke engine completes in a cycle .A top to bottom covers

So for Intake 15 ˚BTDC to 60 ˚ABDC =15 ˚BTDC to BDC+BDC to 60 ˚ABDC=(180-15)+60=225

Compression =BDC to 30 ˚BTDC=180-30=150

Combustion =30 ˚BTDC to 30 ˚ATDC=30 ˚BTDC to TDC + TDC  to 30 ˚ATDC=60

Expansion =TDC  to BDC=180

Exhaust =60 ˚BBDC to 20 ˚ATDC=60+180+20=260

The total sum wont be equal to 720 because of overlapping of each process.

To find out time there is 2500 RPM.Two rotation completes a cycle ()

So one cycle=

for intake

similarly we can compute for other process also