The ignition theory goes like this, the engine piston compresses a mixture of air and gas, which heats up to a fairly high temperature due to the compression, but this temperature is not yet sufficient for ignition, but when a particle of gas comes into contact with the hot surface of the glow plug, it ignites and from here the fire spreads to the remaining gas. More heated spark plugs should cause a large pre-ignition, and less heated ones a smaller one. I would regulate the power and revolutions of the engine as before, the revolutions with the throttle, and the power with the ratio of gas to air, the operating philosophy of the diesel engine.
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very interesting aspect…indeed in tilmans book swiss gengas is written about higher compressed modyfied engines for woodgas…there is to avoid every sharp edges to avoid glowing edges, that makes uncontrolled gas ignition…the idea with the pre-heating candles is great…ignition by controlled glowing …you will do it if it is doable!
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I have some confusion about converting a diesel to sparked ignition. Where does the juice to fire the plugs come from? You can control the timing with something like a crank trigger ignition but it seems you would still need the coil and some sort of distributor, wouldn’t you?
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Today, the tractor worked for 4 hours, a lot of the time in low revs without load, and then fully loaded in high revs, it was towing a large trailer on steep terrain, of course, without a cardan drive on the back of the trailer, it won’t work,… the glow plugs will have to wait
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How do match tractor speed with pto driven trailer wheels?
Do you back off the springs on the shaft clutch so it can slip a little?
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Don, the gear ratio is fine in all gears, even reverse, because I switch the cardan lever to the drive position “through the gearbox” (preko mejnača), the down position, the clutch is for safety.
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Don, some tractors, like Zetor and my Tomo have a pto powered from the gearbox, meaning the speed is based on wich gear you drive in.
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This is what gas ignition looks like after a long stop with a glow plug
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Some engines use glow plug ignition. I don’t know how it works, but in the 1970s I remember a neighbor boy had a model airplane that did this. It burned rubbing alcohol, and it was wire controlled. It would fly around and around in a circle with the boy in the middle. He could only make it go up and down and faster or slower. My question is: how do you control ignition timing?
Rindert
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Rindert, in one of the previous contributions I tried to explain how I imagine setting the ignition time by controlling the temperature of the glow plug. Well, maybe it’s just an illusion, until I try it, I don’t know anything.
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In the next thread I mentioned the video about the shutdown, I increased the playback speed 10x, 15 minutes after the shutdown, flammable gas is still coming out, which even the wind does not extinguish, this is the cleanest and most calorific gas that I can produce, because it is produced without adding air, the air supply is completely closed. Even during operation, very little air enters the gasifier when it is heated to the working temperature, because due to the hot reservoir there is a large expansion of gases in the upper part.
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“He was working so well, but you tore him apart, you crazy head”. Such and similar thoughts are intertwining in my brain, well, some effort and time must be invested to convert Fergi to 100% wood gas. “Crowd in front of the goal”, that’s how I could call the thicket of pipes, at the part where I would like to install the glow plugs and then the spark plugs. I moved the oil filter lower, I have to make the exhaust manifold differently, slightly modify the pipes from the fuel pump to the injection nozzles,… 
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Where do you find your energy Tone? I find myself postponing any modification as long as the wood is burning and the wheels are turning. (Notice the poetry 
)
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Someone has to “sacrifice” for “progress” in converting a diesel engine to wood, and let it be me. Lately I’ve been just fantasizing because there’s no right time for such work, but now that I’ve disassembled the tractor, there’s no going back, I’m very interested to see how it will behave when ignited with glow plugs, if it works, then it’s a win for the diesel motorbikes.
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Tone,
You are a true developer/inventor. You will make changes even when it is working. 
Rindert
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Tone,
I am interested. You said you will control ignition timing with glow plug temperature. Good.
Will you supply exactly equal current to each glow plug? Will there be a knock sensor? Perhaps 4 knock sensors?
Rindert
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Rindert, I plan to connect the glow plugs in parallel and regulate the current strength according to the PWM system, first of course I will set it manually, I hope that no special electronics will be needed, otherwise I will install spark plugs.
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Tone I had not noticed that when you turn on the gas the fan is stopped and that it is the thermal inersia of the gasifier which produces all this gas. amazing
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Tone I’m jealous of your results. this is what the aluminum bath nozzle looks like after just one test
the droppings that we see on the side of the nozzle is a flow of aluminum. the stainless steel pipe has pierced and the bath is emptied
the bottom nozzle was covered with slag
I brushed it. It seems in good condition
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Tone,
This is only my analysis.
Your tractor was running without pilot diesel fuel being injected at all. How is this possible? The woodgas must have been ignited by hot spots in the combustion chambers.
Now if you add hot glow plugs yes your engine will run, but those hot spots will still be there and the glow plugs will not change anything. Also if you add a spark ignition system, the hot spots will still be there, and you will still not have ignition timing control.
We must remove the hot spots somehow. Perhaps by cleaning the the combustion chambers. There are ways to do this without taking off the head.
Rindert
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