today at the track the car started destroying plugs after each run. it would drive fine, perhaps a little on the rich side and i would turn it off myself by stopping the flywheel, rather than letting it run out of fuel. but each time i went to restart it, the plug had blown a coil. it did this with the original OS A3, then an OS 8 and finally a nosram p4 or r4 i forget sorry. the filament looks fine and the guys at hobbyhabit couldnt see a reason for it either. does anyone know what it might be?

How old is your conrod?

When an engine starts eating plugs, it might be a sign that the conrod got to much play.......

its only about 4 litres old. and i've always run it slightly rich. our trac doesnt have a huge straight, so if that is it, i'd be suprised. the car does run fine its only after i stop it that the plug is dead.

what is the motor temping at after a run?

But you've also used this conrod for the break-in of the engine?.....
Well time will tell, if you break your conrod in the next 1-2 litres of fuel, it probably was the problem.......

A glowplug will always keep working even if it loses it's "electrical" connection, so if the wire breaks and doesn't come loose, it will work, but after stopping the engine, and restarting it, the plug will not glow......