Monday, June 27, 2011

Woodgas Carburetor

I have been working on the carburetor. It's not a carb in the true sense, since we are not atomizing liquid fuel. Woodgas enters the engine in gaseous state, so the gas needs only to be mixed with the air in the right proportions. I built a device to do this. Basically a carb throttle and choke, with a side entrance for the woodgas. Here it is painted:

I cut my own gaskets from gasket paper:

And the air cleaner will fit like normal:

I have been planning all along to use an Arduino for automation; this is the main application. I want to have a constant feedback loop from the O2 sensor, telling me if it is rich or lean. Based on that, I will move the choke to allow more or less air. So I need the servo hooked to the choke flap. I finally got around to just that.

The linkage took some experimenting.

I ended up going with a 1-to-1 link to the servo, which I then electronically restricted to 90deg. of movement, matching the choke.

Here's a vid of the "final" version:

Obviously, no O2 sensor yet. I plan to have the manual override in place anyway.