I 100% agree with your engine assessment opinions Mr Wallace.
The flathead opposed Onans and Briggs ARE fuel hogs with very limited compression increase possibilities. Poor, torturous gas flow pathways. Huge HC’s emissions making internal quencing surfaces.
However there was once a very good set youtubes of an inland central California fellow’s woodgas DIY system conversion build up of a cast iron flathead B&S generator unit. He was happy with it.
And on the old Lister Engine Forum there was a guy with a Latin screen name converted a Dodge Slant 6 in his basement with boosted compression and timing changes to 1800 RPM run on street natural gas easily able to quietly, smoothly, generate a solid verifiable live 30 kW electrical if/as he needed AND give him a lot of pumped hot water H for his home heating.
His next steps was to farm for exhaust water heating. His engine radiator, and engine external heat warming his basement to rise up into the undersides of the occupied floors above. Toasty warm feet for the family.
He used to laugh at many of the 950 pound CS Lister single cylinder guys struggling with their hop-away and ground shaking problems. I think they finally banned him off?
I did intentionally buy a new 2800 watt Yamaha Inverter-Genrator unit as the smallest I felt I could reliably woodgas fuel off of my own personal Victory hearth gasifier. The engine is a Yamaha 172cc single cylinder four stroke. This operates variably between 2800-4200 rpm depending on electrical loading. The internal inverter converting the wild three-phase generated AC (~150-300 vac) to stable regulated 60 hertz, single phase,115 VAC output.
My gasifier is the original #1 prototype smaller internal sized hearth versus the enlarged production Victory hearth models. I have very much the same internal volumes and spacing as your biult up Ben Book system. And I have lots, and lots of exprieneces with this particular unit.
You CAN do this with yours too.
Just have to wood inputs fuel and operate for the low gasifer heat/volume loading as I had described.
A multi-cylinder engine, hard drawing gasifier experience is easy. Easy to get heated up and gasifing well. (Easy to heats overload to too hot, too; with big engines demanding!)
Contrary to wishes&hopes: it is the little ones are HARD on every step of it.
tree-farmer Steve unruh
tree-farmer Steve unruh