Glow plug ?

Originally Posted by nebrs13

what are the alloys in them

http://www.scrapmetalforum.com/scrap...ark-plugs.html

Glow plugs have a solid platinum helical wire filament recessed into the plugs tip. Typically they are used in very small combustion engines such as you find in model cars, airplanes and similar stuff. The ignition is accomplished by a combination of heating from compression and heating from the glow plug.
Glowplugs are also used in diesel engines -i found this out when i wondered why it was so ****ed expensive to replace them!

They aren't used in typical petrol/gas engines as they work through spark ignition and not compression combustion.