Glühkerze OS R5

With a glowplug engine, ignition is initiated by the application of a 1.5-volt power source. When the battery is disconnected, the heat retained within the engine's combusion chamber remains sufficient to keep the engine running. Ignition timing is 'automatic': At higher rpm, the plug becomes hitter and, appropriately, fires the fuel/air charge earlier; at reduced rpm, the filament becames cooler and ignition is retarded.

Particuarly in the case of very high performance engines, glowplugs have to be regarded as consumable items. However, plug life can be lengthened and performance maintained as follows:

•Fit a plug suitable for the engine.
•Use fuel containing a moderate percentage of nitromethane unless essential for contest use.
•Do not run the engine lean, or leave the plug connected while adjusting the needle-valve.
•Use a fuel containing as low nitro as possible.

Apart from when actually burned out, a plug may need to be replaced because it no longer delivers its best performance, such as when:
•Filament coil has became distorted.
•Filament surface has roughened while.
•Foreign matter had adhered to filament or plug body has corroded.
•Engine tends to cut out when idling.
•Starting qualities deteriorate.