BillS

Glow Plug - Heat Range
Has anyone found a way to determine the heat range of a glow plug. There are over 20 in my flight box and it would be good to use them since the price has gone out of sight.


Bill

jeffie8696

Is it that you can not identify them?

downunder

Generally there's no way to tell. Some (OS, Enya) mark their plugs while some others (Taipan for instance) colour code the insulator. The rest are pot luck . Probably the only way you might get some idea is to run an engine on a mild fuel (zero or maybe 5% nitro) with a known hot plug and check peak revs. Then repeat with your unknown plugs. Any plug giving lower peak revs will be cooler than the known plug although the difference may be very slight.

BillS

I did find an OS heat range chart and it is helpful. OS does identify the plug with heat range marked on the hex.


However most plugs are not identified by the manufacturer.


Bill

jeffie8696

Merlin Plugs uses a color coding also.

proptop

My Feedback: (8)

Generally speaking, a warmer plug will have a larger fillament cavity, and the coil's wire will be smaller gauge wire...a cold plug, will, quite often have a small hole/fillament cavity and a larger / heavier gauge wire. (something that's easy to check, just for quick eyeball guesstimation purposes...)

BillS

That is good information that I didn't know.


Bill

BillS

More good information. Thanks


Bill