A valve timing diagram graphically represents the exact timing of valve openings and closings as well as fuel ignition in relation to the crankshaft position. It shows the angular position at which the intake and exhaust valves open and close for both two-stroke and four-stroke engines in petrol and diesel engines. The diagrams indicate the typical timing ranges for events like intake valve opening, exhaust valve closing, and ignition in degrees of crankshaft rotation before or after top dead center and bottom dead center.

1. VALVE TIMING DIAGRAMS
TWO & FOUR STROKE
PETROL & DIESEL
ENGINE

2. LUQMAN AHMED

3. TIMING DIAGRAM
 A valve timing diagram is a graphical
representation of the exact moments,
in the sequence of operation, at which
the two valve open & close as well as
firing of fuel.
 It is generally expressed in terms of
angular position of crankshaft.

4. AGRAM FOR TWO STROKE PETROL ENGINE
A
T.D.C
B.D.C
EPC
EPO
TPOTPC
IGN
35 -50 BEFORE BDC
30-40 BEFORE BDC
30-40 AFTER BDC
35-50 AFTER BDC
15-20 BEFORE TDC

5. DIAGRAM FOR TWO STROKE DIESEL
ENGINE
T.D.C
F.V.CF.V.O
E.P.O 35-50 BEFORE
BDC
T.P.O 30-40 BEFORE BDC
B.D.C
T.P.C
E.P.C
15-20 AFTER TDC15-20 BEFORE TDC
30-40 AFTER BDC
35-50 AFTER BDC

6. DIAGRAM FOR FOUR-STROKE PETROL
ENGINE
T.D.C
IVO
EVO
IVC
EVC
IGN
10-20 BEFORE TDC
30-40 AFTER BDC
30-50 BEFORE
BDC
10-15 AFTER TDC
20-30 BEFORE
TDC
BDC

7. THANKS…………..