Ralph,

I'm inclined to agree. As combustion temps go up, the colder plug may start to glow and enhance ignition. That's the theory, now on to prove it.

I've had the experience where a small glow engine would stop. Two seconds later, the starter was applied without glow heat and the engine fired right off. Three seconds later though, would give a no go. Clearly the element wasn't glowing. However, residual heat along with compression heat along with the catalytic effect of the platinum filament allowed a start. Never thought of it at the time but it would have been useful, maybe, to play with heat ranges when doing this stunt. What might we learn? That's been added to the to do list for this season.


AV8TOR,

Agree that one plug is not good for all conditions. Maybe that's where multiple plugs might have some benefit? I'd guess though that with all the R & D the engine companies have done over the years, they would have discovered the validity of this scheme. But what if they just never bothered? Here we have a gas/meth/nitro mix working very well in many cases. Something the engine companies never thought of it seems. And doing this in big engines might translate very well to small engines like a .15, for instance. Consumption of expensive glow fuel in a .15 isn't that much an issue but what if, with the smaller cubes, for whatever reason yet to be discovered, we can go with less nitro? Less methanol? That seems counterintuitive but who knows.

I've been making Biodiesel and with a little luck, I seem to have made some good product. One of the tests to determine this is to mix 10% fuel with 90% methanol and see how much is absorbed. If some fuel drops out, you have that percentage not converted to Biofuel. However, my product will mix with methanol in any ratio. This leads me to the speculation that we may have a new, hybrid fuel/engine. A diesel that uses a glow plug but is far more tolerant of compression ratio.

What for? Well, a pure glow engine delivers its best power at high rpm on smaller props. Small props are less efficient so running a diesel with more torque allows a larger prop with its attendant higher efficiency. Many have tried to make fixed compression diesels and the issue is always that even ambient temps will affect the optimum compression ratio. With a glow/diesel hybrid, this handicap might be reduced or eliminated.

So we have a hybrid fuel large gasser. We may also stumble on a hybrid diesel. Fun to try anyway. Will keep all posted on our progress.

And about plugs. On the 1/2A forum, I posted a method for making heads to take turbo plugs as used on RC cars. This can be done with a drill press and some simple hand tools. Might there be some benefit to using a turbo plug on a gasser/glow hybrid? Don't know but that's another addition to the to do list.