Bill,I like it designed by Gene Turner, and I have a set of plans for it
I'm not so sure you need a more horsepower, the T-100 & Skypup both have similar span loadings. And a Research (NACA) shows span loading is a good indicator of performance at altitude. And the Skypup flew ok at Grand Junction with a Cuyuna 215Bill,
I am waiting for my plans to arrive. Due Monday. I’m thinking that it will need more than 20 HP. If is 4500 ASL here
So I need to find a 30 HP (or so) engine at 60 lbs or so. A half VW would be great but they’re difficult to keep below 90 lbs. did you get your plans from Mr. Turner?
You forgot the very common "Brick Lifting Thermals" (BLTs) that are present during those time periodsFWIW, I absolutely cannot ecommend test flying the Mariah (or any ultralight) at California City or Mojave unless it is in very calm conditions. "Normal conditions" at these airports are not often favorable to ultralights.
There have been recorded reports found in ancient scrolls, speaking of calm conditions at these two airports, but these reports are usually found in the same sentence as reports of the Loch Ness Monster, Bigfoot, the Narwhal, the Kraken, and World Peace.