Nope, it causes instability in whole structure that engine is connected to, which already uses FLT_MAX, but haven't tested with this new heavier version yet, but when I have time must try all sort of things. Propeller itself is actually fine, no issues there, but engine is what causes things to go crazy, need to play also with engine parameters, I did lower inertia and friction a lot as well as power, but it just was too much for first lighter version.
maybe unstable because it is using FLT_MAX so the engine shakes the rest of the vehicle without any dampening on enging nodes
I think node weight was lot lower than Blijo's paperboat, I had it something like 2.4grams per node (test making box with 2.4gram nodes and put then engine to that, it will challenge you ), this is really pushing what game engine can do, that is main reason, but surely jbeam might be possible to improve further. It has now heavier nodes and might be able to handle some kind of engine, but haven't tested.