Building an engine FOR woodgas and/or ethanol

In a few months I’ll be taking a spare Ford 300 inline six to the machine shop. My plan is to build it with high compression in order to optimize it for running on woodgas or E85/E100. My goal is to see how much horsepower we can recover compared to running on gasoline. I also want to have a proven vehicle that will run exclusively on fuels I can make.

Anyone look at the flame travel of woodgas vs ethanol as compared to gasoline? Slow? Fast?

What about cams? I want to go as high a compression as possible. Talk of how high a lift and duration goes over my head. Been years since I was into that stuff. No, make that decades.

My truck is OBD-1 but I may swap it out for something like a Megasquirt non-proprietary engine control system.

I haven’t been around much lately so please point me to other threads if this has been discussed elsewhere.

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Both burn slower and need similarly high compression. The point of diminishing returns is around 13-14:1.

We usually lack torque more than overall power. I’d go with an RV style cam. Port the heads, put some headers on it and a good flow manifold and exhaust, anything to get more flow to the motor.

If you’re going all out for woodgas performance, a complex fuel management system isn’t needed. Just find a carb that can handle the ethanol, and you’re done. Spend the extra time making the woodgas delivery system work properly, it will pay off.


Thanks, Chris! I was thinking the flame travel was the same. Therefore, maybe a greater lift and longer duration. Good to know about the compression ratio. From what I have read, 12.5:1 isn’t too tough to attain. Above 14 sounds like parts made of unobtanium.

The local race engine shop is really interested in my research. They will do the machining plus let me build the engine under their direction, using their tools. That way I get to learn AND save some money from a turnkey engine.

By the way, my next project is a Perkins 4 cylinder diesel in a Ford Explorer. A guy in New Orleans had the 3.9 liter Perkins 4.236 engine in a Ford pickup but decided to go back to a gas engine. So… rather than scrap it, he outright gave me the engine, cross member, radiator, everything. Just need to rebuild the engine as it developed a rod knock. I’ve been running cooking oil for over a decade and look forward to having a bone simple diesel in a non-truck. Got plenty of trucks!

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Only substitute for cubic inches is more cubic inches, over square engine, put the dish in the pistons instead of the head… compression has been discussed, Hell, if I did it i’d have a mag distributor, manual tranny and make is so I’m the one advancing/retarding the timing like in the olden days.


Since woodgas prefers low rpm, try to advance opening your inlet valve and a little valve lifting.
Depending your hydrogen content , your flame speed is not going to be slower then gasoline, hence it might be even faster.
OBD 2 system has also a knock sensor / timing adjusting, not sure if a OBD 1 has it.

dripping ethanol in your hot gas, downstream, performs miracles for octane boosting in a high compression engine

try to have an ignition system with one coil per cylinder and at least avoid sparking when not in compression stroke ( some systems do spark each TDC)