Alfa Romeo Twin Spark engine

Dual ignition in conjunction with gasoline engines means that each cylinder has two spark plugs are used in order to ensure a more uniform, more complete and thus more energy-efficient combustion of the fuel - air mixture. The two spark plugs here may also be of different types.

Basics

Especially for motorcycles with a large stroke per cylinder dual ignition is increasingly being used, as well as in -line four- cylinder Alfa Romeo with the name Twin Spark. In the 1920s, Mercedes -Benz used in the supercharged cars of the W 06 series have a dual ignition. The two Porsche 911 types 964 and 993 ( non-turbo ) and the Porsche 550 were also equipped with such a system. Mercedes she built from 1997 in V6, V8 and V12 engines again, but later renounced it. Unlike Alfa Romeo and Porsche ignition was there out of phase to minimize with the aim of the noise level and emissions.

Function

A dual spark plug assembly ( More broadly, a complete dual ignition system ) is since the 1910s in the aircraft engine used (eg in the Mercedes D III ) and is now in piston engine aircraft duty. To increase operational safety, these engines must be able to work in case of failure of an ignition system on. Characteristic of this magnet - check is before the start: this provides the pilot with brake applied a predetermined engine speed, and turns one after the one and the other from the ignition system. This happens in the runup -area away from the airfield traffic so as not to jeopardize waiting aircraft by possible with the propeller air stream carried stones. Alternatively, the variant is widespread, extending obliquely to the magnetic classified check in the line of waiting aircraft; and wherein the other aircraft are not hit by the air stream. In the magnetic - check is to pay particular attention to an identical drop in speed on both ignition circuits: A speed difference indicates a Zünddefekt in one of the units down, which does not cooperate at least one cylinder in one of the two shutdowns. The magnet - check takes its name from the magneto ignition, an ignition system from the old days of Motorenbaues that works independent of the battery.