Ішкі жану қозғалтқышында цилиндрлердің тұтандыру реті

The sequence of cylinder ignition in an ICE

The firing order of an internal combustion engine is the sequence of ignition for the cylinders. In a spark ignition (e. g. gasoline/petrol) engine, the firing order corresponds to the order in which the spark plugs are operated. In a diesel engine, the firing order corresponds to the order in which fuel is injected into each cylinder. Four stroke engines must also time the valve openings relative to the firing order, as the valves do not open and close on every stroke. Firing order affects the vibration, sound and evenness of power output from the engine and heavily influences crankshaft design.

The numbering system for cylinders is generally based on the cylinder numbers increasing from the front to the rear of an engine (See engine orientation below). However, there are differences between manufacturers in how this is applied; some commonly used systems are as listed below.

In a straight engine the cylinders are numbered from front (#1 cylinder) to rear.

In a radial engine the cylinders are numbered around the circle, in clockwise direction with the #1 cylinder at the top.

The simplest situation is a longitudinal engine located at the front of the car, which means the engine's orientation is the same as the car's. This illustrates that the rear of the engine is the end that connects to the transmission, while the front end often has the drive belt for accessories (such as the alternator and water pump). The left bank of the engine is on the left side of the car (when looking from behind the car), and vice versa for the right bank of the engine. For a transverse engine located at the front of the car, whether the front of the engine is at the left hand or right hand side of the car is best determined based on the side of the car where the transmission is located (which corresponds to the rear of the engine). Most transverse engine front wheel drive models have the front of the engine at the right hand side of the car (except for many Honda cars). As a consequence, the left bank of a transversely V engine is usually closest to the front of the car. For cars where the engine is installed 'backwards' (i. e. the transmission is closer to the front of the car than the engine, or under the engine), cylinder #1 is located towards the firewall, the rear of the car. This is the case for the Citroën Traction Avant, Saab 99, Saab 900 and many rear engine cars.

Contrary to most car engines, a ship's engines are often numbered starting from the end of the engine with the power output. Large diesel truck and locomotive engines, particularly of European manufacture, may also be numbered this way. Cylinders on V engines often include a letter representing the cylinder bank. For example, a V6 engine could have cylinders A1 A2 A3 B1 B2 B3, with cylinders A1 and B1 located at the power output end of the engine.

Common firing orders are listed below. For V engines and flat engines, the numbering system is L1 for the front cylinder of the left bank, R1 for the front cylinder of the right bank, etc. In two cylinder engines, the cylinders can either fire simultaneously (such as in a flat twin engine) or one after the other (such as in a straight twin engine, where either an even fire or an odd fire configuration is possible for a four stroke engine). In straight three engines, there is no effective difference between the possible firing orders of 1 2 3 and 1 3 2. Straight four engines typically use a firing order of 1 3 4 2, however some British engines used a firing order of 1 2 4 3. Flat four engines typically use a firing order of R1 R2 L1 L2. Straight five engines typically use a firing order of 1 2 4 5 3, in order to minimise the primary vibration from the rocking couple. Straight six engines typically use a firing order of 1 5 3 6 2 4, which results in perfect primary and secondary balance. However, a firing order of 1 2 4 6 5 3 is common on medium speed marine engines. V6 engines with an angle of 90 degrees between the cylinder banks have used a firing orders of R1 L2 R2 L3 L1 R3 or R1 L3 R3 L2 R2 L1. Several V6 engines with an angle of 60 degrees have used a firing order of R1 L1 R2 L2 R3 L3. Flat six engines have used firing orders of R1 L2 R3 L1 R2 L3 or R1 L3 R2 L1 R3 L2. V8 engines use various different firing orders, even using different firing orders between engines from the same manufacturer. V10 engines used firing orders of either R1 L5 R5 L2 R2 L3 R3 L4 R4 L1 or R1 L1 R5 L5 R2 L2 R3 L3 R4 L4. V12 engines use various different firing orders. In a radial engine, there are always an odd number of cylinders in each bank, as this allows for a constant alternate cylinder firing order: for example, with a single bank of 7 cylinders, the order would be 1 3 5 7 2 4 6. Moreover, unless there is an odd number of cylinders, the ring cam around the nose of the engine would be unable to provide the inlet valve open exhaust valve open sequence required by the four stroke cycle.

To minimise vibrations, most engines use an evenly spaced firing interval. This means that the timing of the power stroke is evenly spaced between cylinders. For a four stroke engine, this requires a firing interval of 720° divided by the number of cylinders, for example a six cylinder engine would have a firing interval of 120°. On the other hand, a six cylinder engine with an uneven firing interval could have intervals of 90° and 150°. Engines with an even firing interval will sound smoother, have less vibration and provide more even pressure pulses in the exhaust gas to the turbocharger. Engines with an uneven firing interval usually have a burble or a throaty, growling engine sound and more vibrations. The main application of uneven firing intervals is motorcycle engines, such as big bang firing order engines. Examples of odd firing engines are most four stroke V twin engines, 1961 1977 Buick V6 engine, 1985 present Yamaha VMAX, 1986–present Honda VFR 750/800, 1992 2017 Dodge Viper V10, 2008 present Audi/Lamborghini 5.2 V10 40v FSI, Aston Martin 5.9 V12 1999 2018 and the 2009 2020 Yamaha R1 (inline four engine with a crossplane crankshaft).