The ignition sequence is the sequence of the ignition processes of the individual cylinders of an internal combustion engine . It is structurally determined by the type of engine and the shape of the crankshaft . The requirements for the firing order are equally long time intervals between the individual firings and a crankshaft that is easy to manufacture and has minimal stress. By definition, the firing order begins with the first cylinder. The number of ignition points corresponds to the number of cylinders in the engine.
The firing order is indicated in the technical data in the manuals, often also by numbers cast into the engine or a sticker in the engine compartment. With older gasoline engines , it can also be determined by the arrangement of the spark plug cables on the distributor cap .
Direction of rotation and counting direction
For motor vehicles, these two terms are specified in DIN 73021. According to this, the cylinder is "the first cylinder opposite the power output side / clutch". In the case of boxer engines and V-engines, first the left and then the right cylinder bank is counted. (Example six-cylinder V-rear engine installed lengthways, power-emitting side towards the front of the vehicle: left rear is cylinder 1, center 2, front 3 - right rear cylinder 4, center 5, front 6). The firing order is: 1-6-2-4-3-5.
Clockwise rotation : clockwise direction of rotation. Direction of view: on the side opposite the power output.
Left-hand rotation: counter-clockwise rotation. Direction of view on the side opposite the power output.
There are deviations from this standard: For example, with the four-cylinder boxer engines of the Porsche 356 and VW Beetle / Transporter, counting begins "on the power-emitting side in the right cylinder row" (i.e. the 1st cylinder in the front right, the 2nd cylinder in the right rear , left front No. 3 and left rear No. 4). Firing order: 1-4-3-2
In the PSA group (Peugeot, Citroën, DS etc.), the cylinder numbering begins on the side that delivers the power.
Instructions for determining the firing order
In cases in which there are no correctly connected cables and no documents are available, the firing order can be recognized for two-stroke engines by ascertaining the sequence of the top dead centers ; for four-stroke engines, because the crankshaft runs twice per four-stroke process, the sequence in which the compress the individual cylinder (in the simplest case, the spark plugs are removed, the engine is turned the right way around and the pressure in the compression cycle is determined with a finger).
Typical firing orders
- Three-cylinder: 1-3-2 or 1-2-3 Subaru diesel
- Four-cylinder: 1-3-4-2 or 1-2-4-3
- Five-cylinder: 1-2-4-5-3 or 1-3-5-4-2
- Six cylinder: 1-5-3-6-2-4 or 1-2-4-6-5-3 or 1-4-2-6-3-5 or 1-4-5-6-3-2
- Eight-cylinder: 1-6-2-5-8-3-7-4 or 1-3-6-8-4-2-7-5 or 1-4-7-3-8-5-2-6 or 1-3-2-5-8-6-7-4
- R4 engines with crossplane crankshaft: 1-3-2-4 ( Yamaha CP4 , e.g. YZF-R1 from 2009)
- Four-cylinder: 1-3-2-4
- Six cylinders: 1-2-5-6-4-3 or 1-4-5-6-2-3 or 1-4-3-6-2-5 or 1-2-3-4-5-6 ( Mitsubishi 6G7 engine) or 1-4-2-5-3-6 ( Ford Cologne V6, Ford Essex V6)
- Eight-cylinder: 1-6-3-5-4-7-2-8 or 1-5-4-8-6-3-7-2 or 1-8-3-6-4-5-2-7, or 1-8-4-3-6-5-7-2
- Ten cylinder: 1-6-5-10-2-7-3-8-4-9
- Twelve-cylinder: 1-12-4-9-2-11-6-7-3-10-5-8
- Six-cylinder VR engines : 1-3-5-6-2-4 (VAG VR6 engines do not have this firing order)
- V6 engines: 1-6-2-4-3-5 or 1-4-3-6-2-5 (some Audi and VW engines) or 1-4-2-5-3-6 ( Mercedes -Benz )
- V6 engines with cylinder bank angle 90 °: 1-6-3-5-2-4 ( PRV engine )
- V8 engines from General Motors / USA: 1-8-4-3-6-5-7-2
- V8 engines from Ford / USA, Scania / Sweden: 1-5-4-2-6-3-7-8
- V8 engines from the Porsche 928 : 1-3-7-2-6-5-4-8
- V8 engines with 180 ° crankshaft: 1-8-2-7-4-5-3-6 or 1-8-3-6-4-5-2-7
- V12 engines from BMW : 1-7-5-11-3-9-6-12-2-8-4-10
- V12 engines in the Lamborghini Murciélago / Reventón: 1-7-4-10-2-8-6-12-3-9-5-11
- V12 engine in the Lamborghini Aventador: 1-12-4-9-2-11-6-7-3-10-5-8
- Four-cylinder: 1-4-3-2 or 1-2-3-4
- Six cylinder: 1-6-2-4-3-5
- Eight-cylinder: 1-7-6-4-5-3-2-8 or 1-6-4-7-5-2-8-3, 180 ° V-engine: 1-4-3-2-5 -8-7-6 (180 ° V)
- Sixteen-cylinder from the Bugatti Veyron : 1-14-9-4-7-12-15-6-13-8-3-16-11-2-5-10
- Audi A8 W12 engine: 1-12-5-8-3-10-6-7-2-11-4-9
- Richard van Basshuysen , Fred Schäfer: Handbook internal combustion engine. Basics, components, systems, perspectives. 3rd completely revised and expanded edition. Friedrich Vieweg & Sohn Verlag / GWV Fachverlage, Wiesbaden 2005, ISBN 3-528-23933-6 .
- Max Bohner, Richard Fischer, Rolf Gscheidle: Expertise in automotive technology. 27th revised edition. Verlag Europa-Lehrmittel, Haan-Gruiten 2001, ISBN 3-8085-2067-1 .
- Peter Gerigk, Detlev Bruhn, Dietmar Danner: Automotive engineering. 3. Edition. 4. Pressure. Westermann Schulbuchverlag, Braunschweig 2000, ISBN 3-14-221500-X .
- ↑ Horst Bauer (Ed.): Kraftfahrtechnisches Taschenbuch. Published by Robert Bosch GmbH. 24th updated and expanded edition. Friedr. Vieweg & Sohn Verlag, Wiesbaden 2002, ISBN 3-528-13876-9 , p. 435.
- ↑ Yamaha Design Cafe