Yes, it's wet sump. I don't know the run time potential yet, my guess is 90 minutes or more with this airframe. This is the worst type of airplane possible for duration testing, as you have to really fly it all the time. For that I would prefer a huge 3 channel design that I can trim to fly in a big circle overhead, hands off. I could save some weight if I modify a propane cylinder shorter, as I carry much more fuel and tank than needed for normal flying.
I have also a converted Honda GX35 (also wet sump) that doubtlessly would have made greater power on the propane, but I wanted the novelty of flying a plane with this flathead engine.