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Bob Verhaeghe, Merritt, NC firstname.lastname@example.org
This is my first try at making a spark plug. I was thinking a hand made plug for the RLE engine would be a nice touch. What you see is 10 MM long reach plug. The insulator was made from Delron. (The engine runs quite cool and figured the plastic will hold up at the low temps.) The base was made from cold rolled steel-CRS ( two parts). The center electrode was made from 3/32 music wire. The plug is a rimfire design. and with a 3/16 dia. insulator at the tip, this gives a .046 spark gap. I also recessed the insulator to prevent tracking at the tip. The spark pattern looks good when tested. I'm not sure about such a large gap but time will tell. The initials are for show and shouldn't effect performance,... I Hope!! The next step will be to run the engine with the plug, that will be the true test.
This plug was used at the 2003 Cabin Fever show for it's first test.
The engine was run for over 12 hours in the three days there. When removed
after the show there was a small build-up of carbon but the plug was still working well. There wasn't any sign of tracking at the insulator. I do think a plug of a hotter design would be better. Thinner wall at the end of the base and thinner center electrode might help stop carbon from forming if it ran hotter. The biggest problem is that the engine runs so cool. The fuel used was Ozark stove fuel with 5% WD-40. It did start on the first flip every time and only stopped when it ran out of fuel. The ignition system is a buzz coil by Jerry Howell, Modelelect coil, and powered by four "D" size alkaline batteries. (The batt's. have many hours on them. They are the same ones from day one on this engine) They just keep going and going and going.
All-in-all I was pleased with results and will continue to use this plug in the R.L.E. engine.
I did try the same design at 1/4-32 size in my Green Flash engine but it fouled out after a short time. Repeatedly!! I will be making what I think will be a hotter plug and trying that out soon.
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