jalpaug

I thought they were used only to start the engine and then the fuel ignited from compression. A guy pointed out the other day that there are different heat ratings for different glow plugs. What does that mean? He seemed to think that the wire keeps glowing hot the whole run and the plug can have an affect on the temp that the engine is running at. Can anyone clear this up for me? Thanks

CHassan

My Feedback: (13)

The plug will have no bearing on the temp your engine runs.

I'll send you to I8tweety's post in another thread.
http://rcuniverse.com/showthread.php...55&forumid=215

Or if you are llike me and normally to lazy to click and read the thread, here is some of the highlights
What's the physical difference?

A "cold" plug has a thicker wire and fewer coils than a "hot" plug.



When do I want to use a "cold" glow plug and why?

You should run a cold plug if you are operating your engine at higher temperatures (say 260 degrees and above for argument sake). The thicker wire in the plug requires higher combustion chamber temperatures to reach proper operating temperature (to get the coil in the plug to stay hot enough). This also helps keep the glow plug from burning out (when compared to a "hotter" plug).


Why would I ever want to run a "hot" glow plug then?

If you are running your engine at cooler (and more engine friendly temperatures), the thicker wire of the cold glow plugs may not retain sufficient heat to make your engine run properly. If the coil in the glow plug is not warm enough, the fuel in the combustion chamber will ignite slower and later in the cycle reducing performance. You can experience sluggish acceleration from an idle along with a propensity to stall.


When selecting a glow plug, decide what temperature range you want to run your engine at and tune your engine accordingly. Putting in a "cold" glow plug will not reduce engine temperatures. If you were running 300 degrees before, you will run 300 degrees after (on a positive note, the cold plug will last longer than a hot plug at that temp range).

Krusty

The plug wire does continue to glow after the igniter is removed once the engine is running and throughout the whole run. If you were able to see inside the exhaust port while the engine was running, you would see the "glow" reflection of the glowplug on the top of the piston. Way back when, before mufflers were required, the exhaust port opened directly into the atmosphere.