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Author Topic: Comet Chamber/Glow Plug  (Read 4222 times)

Geno

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Comet Chamber/Glow Plug
« on: October 14, 2006, 11:34:13 PM »
The pictures I’ve seen of head plug mounted glow plugs show the tip of the glow plug sticking out ¼-½” into the chamber and right in the path of the injector spray. Does anyone think this would take away from the comet chambers effectiveness and how much? Sir Harry spent a lot of time on its design and I want it to work correctly, but its also getting cold.
Thanks, Geno

slowspeed1953

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Re: Comet Chamber/Glow Plug
« Reply #1 on: October 15, 2006, 01:22:08 AM »
Geno, could please you point me in the direction of any of the pictures you speak of?

Peace&Love :D, Darren

Geno

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Re: Comet Chamber/Glow Plug
« Reply #2 on: October 15, 2006, 12:18:37 PM »
Actually, I only recall one pic and I *think* it was here. The rest is speculation on how it probably is done in other cases.
Geno

biobill

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Re: Comet Chamber/Glow Plug
« Reply #3 on: October 18, 2006, 05:13:55 AM »
Hi Geno. I have an opinion for what it's worth. Perhaps one of the more learned members will steer me straight if I'm wrong but it seems to me that in an indirect injection engine the spray pattern is not terribly critical as most of the combustion takes place in the precombustion chamber. In a direct injection engine it is of far more importance because an uneven spray pattern can cause hot spots on the cyl. walls. As long as the fuel is properly atomized in your precombustion chamber type engine I can't see where the flame front "shape" would make any difference, especially not at 600 rpm. In a high rpm engine maybe or perhaps in an aluminum head head engine with combustion chamber inserts I suppose hot spots could cause the chambers to loosen but they all have a glowplug stuck right in the spray pattern too. And the Lister is solid iron. It would be interesting to see some time lapse photography of the combustion process in a hot engine to see if the fuel actually makes it to the glow plug or if it's already burned. All I know is that in a cold engine it hits that red hot plug and away you go. Yahoo. My setup should be here Thursday if you want to check it out. Bill 
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Geno

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Re: Comet Chamber/Glow Plug
« Reply #4 on: October 19, 2006, 12:38:21 PM »
Good point Bill. Modern IDI heads have glow plugs right next to the injector. I'd like to see your setup as well.
Thanks, Geno