Posted by Krzysztof Lis on April 4, 2008
Wood gas is an interesting fuel for internal combustion engines. It can be used in almost all four-stroke engines, both compression ignition (diesels) and spark ignition engines. In this article you’ll read how to use wood gas in engines.
Spark ignition (gasoline) engines
In gasoline engines the fuel is ignited by an electric spark made by spark plug. If you substitute the gasoline / petrol with some other fuel, like LPG for example, the engine runs fine. So why not fuel your engine with wood gas?
For engines with carburettor you simply turn the gasoline flow back to the fuel tank. You add wood gas / air mixture (of proper composition!) in the same place where the air was originally introduced. The mixture is compressed inside the engine and then ignited by spark plug.
For engines with fuel injection you need to buy some electronic device that’ll “cheat” the injection controller. Such a device is a part of LPG or CNG conversion sets. When you stop the gasoline flow in the engine, the injection controller will probably stop your engine or do something even more stupid.
Compression ignition (diesel) engines
Fuel in diesel engines is ignited by itself, because it is injected to the engine when air is under high pressure and hot. Wood gas will be introduced as in gasoline engines, in a form of wood gas / air mixture. Compressing it will not lead to ignition, so you need to leave a small dose of diesel fuel to be injected to the engine. This dose is called pilot charge. It can be petrodiesel, biodiesel or even vegetable oil. It will be ignited and ignite the fuel mixture. This way you can save up to 80% of diesel fuel or even 95%, if you substitute the injection nozzles with smaller ones.
Oh yeah, there’s also another way to ignite woog gas in diesel engines. You can substitute the whole injection system with ignition system (ignition coil, spark plugs instead of glow plugs). But if you decide to try this, you wouldn’t be able to use diesel fuel in this engine anymore.
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