Thanks everyone, lots of helpful info.
I did think of this, and might just put a momentary switch on the wire that grounds the plug. Wouldnt hurt to have a way to shut the thing off…
We may both be confused, what configuration do you use on your air and gas valves, Koen? Are they plumbed the way I have it set up above, or do you put your “throttle” valve below the T and have woodgas coming unrestricted into the T opposite the air intake?
Do you have a picture of this setup? I am not sure I am following you entirely, but it sounds like you are changing the timing of the engine by using an independent power supply to fire the plug? I am not an expert on small engines, so I dont quite understand how the change in timing will change how the engine behaves. Now I am curious, though.
This may well be the case, I am more of a DC guy, so alternators are a little bit confusing to me. I suppose It would have a system to prevent the engine from overcharging the start batteries that it is designed to charge.
As for the diversion loads being a waste of precious woodgas, I disagree. My primary diversion is a 20 gallon hot water heater that preheats water for my propane on-demand heater, and once the thermostat kicks that off, I start space-heating my shed where my shower is. I am not sure if it is really very efficient, but If i can burn less propane I consider it a win.
This seems like a very good point, which I had not considered. I might actually think about mounting the intake manifold directly to the frame I am going to build, and then use a section of flexible hose to make the final connection to the engine. What do you think of that idea? That might make it easier to swap out valves and reconfigure everything anyway.
I went with the brass ball valve because it seemed the least prone to having parts that would melt. I know that in theory the charcoal gas should not be hot, but I wasnt sure if it would be better to err on the side of caution. At some point the engine is going to start running poorly if the gas is too hot, right? Has anyone tried to measure the upper limit for gas temp before an engine either stops running or gets damaged?
Haha, I was looking at a 24" model, but now that you mention it… I DO want to be able to roll 36" material!