So I have a 1981 4x4 dodge 3/4 ton truck I've decided to retire from highway service since I have a replacement. Thinking of removing the cab and replacing it with boiler and engine of some kind. I have a partly built 40 HP ofeldt boiler, Since it'll be wood fired I think I'll add a curtain of pipes around the inside of the firebox as I finish it, making it at least 50 HP. (have to calculate to get a more accurate figure) turning it into sort of a hybrid between the ofeldt and yarrow. I just bought a small antique engine, westinghouse 2 cy single acting, but it's too small for the truck and boiler. Will make a small boiler to go with it for smaller jobs. I have most of the parts to assemble a 40 HP single cylinder engine of the old style kind, 36" flywheel, etc. but I think I'll save that for a military truck/tractor project. So I'm thinking what's the possibility of a custom head for an auto engine with steam valves in it. I have a 2" thick slab of cast iron I could cut head size pieces from. A few engines laying around that could be used. inline 4, inline 6, horizontal opposed 4, V8. the inline 4 may be the easiest. horizontal opposed 4 next, but it would take 2 heads with 2 crossover lines. I have lathe and milling machine. Although the large milling machine I bought is still at a friends shop about 8 miles away. I can use it where it is until I make a place for it.
So what are the problems associated with converting auto engines? Lubrication issues? Has anyone tried a mix of synthetic (amsoil) marine gear lube (designed to operate OK with quite a bit of water contamination) and perhaps a metal base lubricant additive? (which adds powdered bearing metal to the oil.) And what kind of valves could be machined into a 2" thick head? All I can imagine is some version of a corliss valve. Provided they can work under at least 400-500 PSI. Anything better? A balanced poppet would be nice but increase the complexity. Or perhaps I could use the original heads and original poppet valves for exhaust and custom valves for the inlet through enlarged plug holes. That might be the simplest version. Sitting here thinking about it, I just dreamed up a rotary distribution valve that would not have side wear issue like a corliss style, not pressure balanced, but could be greased or oiled externally with drip oilers. It could be cast iron on cast iron, or brass to cast iron. Though brass may be too soft for the pressure involved. A disc that rotates on a seat, driven by shaft through seal packing, holes in disc distribute steam to ports in the seat, small hole near center from portside for grease or oil insertion.
What I'm after is a practical firewood powered vehicle for work service in the woods and farm. I've tried woodgas and don't like it. wood has to be quite dry and chopped up into small pieces. (too time consuming) and the reliability is limited. I like steam a whole lot better, especially since I started out in life interested in it when I first discovered it almost 40 years ago. I have firewood to process in quantity, for heating and biochar production. (some 20 acres to get cleared) for that I'd like the option of generator on the engine for electric chain saw, a hydraulic pump on it to run an attached log splitter, external powering of sawmill, sorghum press, grain mill, grain thrashing when I get a trashing machine built, as well as steaming grow beds to kill weed seed. All kinds of jobs available for such a machine, truck and/or tractor.