The ignition sequence of the automobile engine, or the working sequence of the engine, refers to the sequence of the work process of each cylinder of the multi cylinder engine.

Today’s automobile engines are basically reciprocating four stroke engines. Only one stroke of them generates power by doing work, and the other three strokes consume power.

In order to make the engine run smoothly, in addition to setting a large flywheel to store energy and balance speed, each cylinder should work evenly. Therefore, each cylinder of multi cylinder engine must work reasonably in a certain order.

What are the basic principles of engine working sequence? The basic principle of engine working sequence is: the work interval angle of each cylinder shall be balanced as far as possible, and the included angle of the two cylinders working continuously to the corresponding crank shall be equal; The two cylinders doing continuous work shall be as far apart as possible, preferably alternately in the front half and rear half of the engine, so as to reduce the continuous load of the crankshaft main bearing on the one hand.

On the other hand, it can also avoid the phenomenon of scrambling when the inlet valves of two adjacent cylinders are opened at the same time, so as to make the intake distribution of each cylinder uniform; For V-type engine, the left and right exhaust cylinders shall work alternately as far as possible.

The working sequence of the engine is determined by the crank arrangement of the crankshaft. Crank is the basic type of crankshaft. One crank pin, two left and right crank arms and two left and right main journals form a unit crank.

The opening time and duration of the valve on the engine, the ignition sequence of the distributor and the injection sequence of the fuel injector should be matched with it to make the engine work normally and run smoothly. The following is the working sequence of some common engines.

The firing angle of the in-line engine is 720 / 4 °. The four cranks are in the same plane. The engine operation sequence is 1-3-4-2 or 1-2-4-3.

Basic principles of engine working sequence

Firing sequence and crank arrangement of in-line six cylinder engine: the firing interval angle of four stroke in-line six cylinder engine is 720 ° / 6 = 120 °, and the six cranks are arranged in three planes respectively, and the firing sequence is 1-5-3-6-2-4.

Basic principles of engine working sequence

The in-line six cylinder engine has another working sequence, 1-4-2-6-3-5,. The first is usually called the right form and the second is called the left form.

Basic principles of engine working sequence

The firing interval angle of V-type six cylinder engine is still 120 °, and the three cranks form 120 ° to each other. Working sequence r1-l3-r3-l2-r3-l1. Facing the cooling fan of the engine, the right cylinder row is represented by R, and the cylinder numbers from front to back are R1, R2 and R3 respectively; The left cylinder is represented by L, and the cylinder numbers are L1, L2 and L3 respectively. It can also be briefly described as: 1-6-3-5-2-4

Basic principles of engine working sequence

The firing interval angle of V-type eight engine is 720 ° / 8 = 90 °, and the four cranks form 90 ° to each other. There are basically two working sequences: r1-l1-r4-l4-l2-r3-l3-r2, l1-r4-l4-l2-r3-r2-l3-r1, or 1-5-4-8-6-3-7-2 and 1-5-4-2-6-3-7-8.


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