Search Email

A     B     C     D     E     F     G     H     I     J     K     L     M     N     O     P     Q     R     S     T     U     V     W     X     Y     Z





The history of the ignition (1)

When we speak of the history of ignition, what we're practically doing, is accompanying the progress of the petrol engine, for good reasons, also called the Otto-engine. Actually, we should begin even earlier, with the Frenchman Lenoir, and his atmospheric gas engine. Since it is here that one can speak of a continuously running machine.

The Lenoir-engine is typical for having one ignition each, at TDC above- and BDC below the piston. Thereby, two platinum wires each end in the combustion chamber, this can safely be imagined to be the first spark plug, and this in the year 1860! With this stationary engine, the power supply did not have to come from an accumulator or a battery, one could take the current directly from a type of generator.

Here, also for the first time, the ignition coil appeared, with primary- and secondary windings. The fundamental difference to todays equipment: Up to 50 sparks per second were continuously produced and through a high-tension switch, distributed to the correct spark plug. Thus, Lenoir also invented a sort of distributor, except that this one didn't rotate but shifted back and forth between two contacts.

The atmospheric gas-engine does not require an exact ignition-point, because there is no point where the mixture is compressed to the maximum. It is an uncompressed air-fuel mixture which, after the ignition, moves the piston. Not a partricularly effective process. This is why the Lenoir-engine is famous for its relatively low performance and its heavy engine-weight. Because of the noise development caused by the multiple ignitions, one speaks of a 'buzzer-ignition'.

Already Otto's and Langen's atmospheric gas-engines, after 1864, were superior to Lenoir's engine as far as the performance to weight ratio was concerned. This is particularly valid as far as the four-stroke-engine, built after 1876, is concerned. However, this was first ignited by an open flame, which burnt in a seperate chamber, near to the cylinder-head. Whenever an ignition was necessary, this chamber was opened to the cylinder-head. We'll see later, that this process, as simple as it would seem, certainly had its disadvantages.

Daimler, who had worked at Deutz, basically stuck to the principle of the ignition. Due to the fact however, that at speeds of over 200 RPM, it apparently no longer worked, indeed, possibly even extinguished the flame, he then installed a glow-pipe, which was heated from one side and transferred only the heat to the combustion chamber. Of course, this is a continuous ignition, which basically, only works below a certain RPM and under certain strain conditions. Daimler and Maybach undertook any number of test-runs, before their engine actually ran at approx. 650 RPM.

It is said that Maybach apparently, never liked this type of ignition at all and was particularly afraid of e.g., the fire-risk linked with it. After all, underneath the actual burner itself, a bowl was installed for the purpose of pre-heating the burner before it was put into operation, plenty of possibilities for operational errors. Of course, the burner was fueled with petrol, or more precisely Ligroin. Indeed, we are dealing with an engine that had to operate in wind and weather, not particularly favourable for the reliable running. 05/12

Next page