Twin Spark. "Double spark") is an ignition system with two candles per cylinder. The system was introduced by Alfa Romeo to reduce fuel consumption and engine power distribution with greater efficiency. Twin Spark invention
Twin Spark invention
The Alfa Romeo Twin Spark technology was first used in the Alfa Romeo Grand Prix car in 1914. In the early 1960s, the company started a new stage of development, which the company applied in the development of its racing cars Alfa Romeo GTA and TZ to achieve more power and elasticity of engines without increasing the volume.
The owners of the Alfa Romeo with their six-cylinder engines and Twin Spark have to buy 12 candlesticks for them
In the early and mid-1980s, Alfa Romeo has introduced this technology into its serial vehicles to increase capacity and meet the new stringent emission limits in the exhaust gas.
Twin Spark system
In the modern Twin Spark, this is a duplicate ignition system that has been used on many Alfa Romeo cars. The main design feature of the Twin Spark system is the use of two spark plugs for the blending of a mixture in one cylinder. The 8-valve engine installed in this system was installed on the Alfa Romeo 75, 164 and 155 models. The 16-valve Twin Spark ignition engines picked up Alfa Romeo 145, 146, 155, GTV, Spider, GT and others.
Twin Spark ignition system
Early engines, equipped with the Twin Spark ignition system, did not differ from the engines of other manufacturers. The first generation of the ignition system with two candles on the cylinder of Alfa Romeo developed and applied for even fuel combustion for one stroke of compression. The Twin Spark ignition has resulted in fuel savings and stable engine performance under different loads. In the 1980s, the system was applied on 8 valve engines with one distribution shaft. Twin Spark provided two consecutive flashes over a single working cycle divided in hundredths of a second.
The [ [ Twin Spark]] system has been actively used by Mercedes, particularly for a small Smart with an engine of 0.66 liters of 3 cylinders and 6 candles
For early Twin Spark systems, two separate coil-off circuits are used for each circuit. The ignition bell runoff was equipped with two working contacts. We were in contact with each other. Each rotor pin matched its "electrode ring" in the ignition control lid.
The electrodes in the lid of each group of candlelight are located not strictly within each other, but with a small indentation that corresponds to the direction of rotation of the Trambler's thumb. Thus, the upper contact of the jogger took place opposite the "his" electrode in the cover for the hundredths of a second before the bottom. Thus, a slight delay was realized between the first and second candles, which aggregate the mixture in the same cylinder.
Alfa Romeo Twin Spark
Later, the development of Twin Spark went hand in hand with the introduction of progressive solutions of the Italian engineers into the design of the engine itself. On the later eight-valve engines Alfa Romeo (90s and 2000s), the combustion optimization of the fuel-air mixture was ensured by the simultaneous burning of the mixture at two points by two candles. This technology has enabled the flame front to spread out of the two epicentre points on the conditional vertical lines through the intake and exhaust centers. The flame front at two places is less than a distance, allowing the Italian engineers to reduce the timing of the ignition. The reduction in this parameter greatly affects the efficiency and impact of the engine, because when the angle of advance is reduced, the piston moves to the top of the dead point and compressing the mixture is less resistant (flash occurs a little later). In addition to the fuel economy, in the eight-valve engine Alfa Romeo 8V, two identical candles were able to be applied with the lower part of a very large diameter of 44 millimetres. This means that the ventilation of the combustion chamber after the outbreak has become much more effective.
When the ignition comes out of one coil, which means turning off half of the candles, the Twin Spark engine will not shut down
In the 16-valve Alfa Romeo with the Twin Spark engineers, the engineers placed one candle in the center of the cylinder. In order to place the second spark plugs in the combustion chamber with four valves per cylinder, the developers decided to use a smaller diameter candle installed in the side part of the combustion chamber. Although the effect of the second candle on the combustion of the mixture is inferior to that of the first, its application has ensured the idling of idling at a highly depleted mixture (prior to 1801 AFR!). In fact, this means that the engine can develop an impressive torque at a low speed, and smoothly, without ropes, work in a small load, using the minimum amount of fuel. For example, the engines of the Alfa Romeo TS 1.6, 1.8 and 2.0 use candles with a diameter of 10 to 14 mm. The main use is the iridium candle Long Life with a platinum electrode and an interval of up to 100,000 kilometers.
The duplicated Twin Spark ignition system was used on the Alfa Romeo engines until 2009 and was no longer relevant only to the production of Alfa Romeo JTS engines with direct injection.
Twin Spark Ignition Features
The main feature is the need to purchase two sets of candles to replace. However, this factor has proven to be without prejudice to the reliability of the system, which has proved to be a good one.
Interesting facts about the Twin Spark system
In the early 1980s Japanese company Nissan worked closely with Alfa Romeo. Some models developed by Nissan were in Europe under the Italian brand. For example, the Nissan Pulsar N12 model was issued as Alfa Arna.
Nissan, in turn, used the twin spark ignition on some of its engines. A good example is a four-cylinder CA series engine, such as the CA18S in Nissan Bluebird.
