This is for all the frustrated builders of fire eater engines. In the Duclos design, and I expect some others, The flame is a critical and hard to determine item. Any change from the original burner design may not run. If you have a good running Duclos fire eater and make small changes in flame position, you get major change in speed. Big changes in flame position and the engine stops.
When you have completed the build, spin the flywheel (it should spin easily) and if everything is right, you get an audible pop. If the timing is incorrect or the valve is not sealing, you don't get the pop. Small timing changes can be made on the valve rod where it connects to the slide valve.
If the engine pops reliably, concentrate on the burner and flame. Even the length of exposed wick makes a difference. When you have everything right, this is an engine that will start every time with one spin and needs no warmup.
As a BTDT, I threw away my doorknob burner because all the alcohol evaporated out of it when sitting on the shelf. I made a new leak proof burner with O ring seals and spent the next several weeks trying to get the engine to run again. The length of the wick tube turned out to be the critical dimension.
When you have completed the build, spin the flywheel (it should spin easily) and if everything is right, you get an audible pop. If the timing is incorrect or the valve is not sealing, you don't get the pop. Small timing changes can be made on the valve rod where it connects to the slide valve.
If the engine pops reliably, concentrate on the burner and flame. Even the length of exposed wick makes a difference. When you have everything right, this is an engine that will start every time with one spin and needs no warmup.
As a BTDT, I threw away my doorknob burner because all the alcohol evaporated out of it when sitting on the shelf. I made a new leak proof burner with O ring seals and spent the next several weeks trying to get the engine to run again. The length of the wick tube turned out to be the critical dimension.