Glow Plugs

[wesr_05]

What does all the differnet hot cold and medium glow plugs mean.

 

[gnarkill]

Hot glow plugs are generally used with fuels with a low nitro content. Cold are used for fuel with a high nitro content, and a medium plug is good for fuel with about 20% nitromethane. Although any plug will work with any fuel, It's life span decreases.

 

[olds97_lss]

The temp of a glow plug in combination with the compression and nitro content of the engine alters when the mixture explodes in the combustion chamber. It's a way to change the timing of the engine.

Higher nitro fuel explodes easier than lower nitro fuel. Usually 20% down to 10% nitro can use a hot rated plug and get decent combustion at the right time. 25% on up generally requires a cooler plug.

If the plug is wrong on the hot end, the fuel will combust as the piston is coming up, so it will rob power due to the engine constantly fighting itself to run.

If the plug is wrong on the cool end, it will combust after the piston has reached the top of the stroke and is on the way back down. This will cause poor performance as well since some of the "bang" is blowing out of the exhaust.

 

[Tombomb]

Didn't I read somewhere you also use hot plugs in the summer and cold plugs in fall winter?

 

[neobart]

If anything it's the reverse, but I use the same plug year round.

 

[olds97_lss]

Didn't I read somewhere you also use hot plugs in the summer and cold plugs in fall winter?

Well, to me, it seems irrelevant. Since the glowplug is directly related to compression/nitro content. Ambient temps don't play a part in either of those.

I run the same medium plugs year round.