How do, Charlie
Yes, some addys to work with would be fine- been headscratching the engine problem- seems to me that contact with a founderer and engine designer would be critical. I envision a straight-four crankcase cast to specifications to accept four Lycoming jugs, plus custom crankcase and camshaft. This way, parts ain't such a problem. You could push the same idea with a 'dub engine, but here I ain't to sure 'bout the HP and RPM situation- I suspect you'ld have to go with Porshe big end hardware and/or a step-down at the prop. The idea is four jugs poking up (most folks don't count these things), air cooled (put the 'radiator' where you want) and lightweight. I was thinking in terms of a 7/8 scale bird, so's a four-banger could be found that would have the poop to pull the beast. By 'streatching' the crankcase you would have something that would even have a similar profile (from a distance). Might lose some weight-to-HP ratio, but not enough to ground the project.
What engines do you know of that would work here?
Gregory F. Howard