why don't we use glow plugs instead of spark plugs?

[noshell]

I've noticed that my friends chinese diesel heater uses a glow plug to ignite the diesel, not a spark plug. Could this be a suitable ignition source to run a liquid fuel engine?

[richardm]

some older turbines like the PT-6 used glow plug And they worked pretty well. However the placement of the plug in the combustion chamber is critical as it must get wet with fuel. And also keep in mind that such a glow plug would be exposed to a pretty strong airflow wich may keep it from getting hot enough

[noshell]

Nice, thanks for that.

I may go that route on the next engine. I've found spark plugs a little bit hit and miss.
Intuitively I would think a glow plug is more consistent.

[richardm]

I guess it depends also on the type of glow plug used. I would give the type a try. www.amazon.ca/truck-parts-Thermostart-E1NN9A436AA-International/dp/B08NDNY4NB

[noshell]

what on earth is that?

[noshell]

some of these tractor glow plugs look like giant light bulb filaments haha

[richardm]

Watch this www.youtube.com/watch?v=_tTwL5Sb4f8

[noshell]

That is bloody brilliant

[richardm]

Brilliant it might be if the plug is correctly located . Some modifications might be required.It might or might not need the external fuel supply if the atomized fuel reaches the hot element....
Or it could be used with its own fuel supply as in the intended use and lighted up before commencing the start..
Just widely opened to experimentation

[racket]

These are what the "kero start" RC turbines use , just a smaller version.

Lotsa flame heaters available for tractors

[richardm]

Hi John! I have 2 of those on hand as I told you last march. Im planning some experiments next winter ..Also bought some nuts to fit it in a mock combustor so to see if some air could be used to feed and blow the flame further away in the combustor.

[racket]

Hi Richard

Yep , a bit of "forced" airflow should get things moving around ...............I never got around to playing with my ones as I had troubles finding suitable fittings for the fuel supply inlet .

Cheers
John

[richardm]

Yeap I had a look when I received it and I had that same thought its been sitting on my bench since waiting for winter time when I revert to my cave... Might have to machine some fittings..or find some on the web maybe.

[richardm]

I tried to remember about those glow plugs that were fitted on the PT-6 Engine back then ( I flew em over 40 years ago) I found this on the web .

www.aviationpros.com/home/article/10383459/pt6-ignition

While reading I realized that one may not need the fuel line to the thermostart plug after all. In the PT-6 those plugs just get wet from the fuel spray. Correct placement in the combustor would be of importance.

The description in the article matches pretty much that of thermostart pug but without the fuel feeding line. I think one could easily do without the ballast system.

[richardm]

Here s what those PT-6 glow plug look like ww2.txtav.com/Parts/PartSearch/PartsDetail/AGF2-6

Makes me think of those cigarette lighters found in older cars.. Just another idea.. Maybe one of those lighters could do the job with the help of little overvoltage. maybe 18 volts instead of 12 from a buck converter?

All it takes is a little imagination a few dollars and time to experiment..