Hi Rob. I have about 400 flights on two lightnings, one with a Titan and one with a Rhino. I have also seen Gordon fly his on a P180.

I think the Rhino at 37 pounds thrust (engine weight 3.75 pounds) is perfect for the plane. Vertical is all you could ask for and plane weight will be in the 38 pound range with a blue box cockpit. Lose the cockpit, put in a TAMS pipe and you will get a weight around 35 pounds. Ehab hit the nail on the head ... this plane is in its element in constant speed IMAC type flight.

The plane flew ok on the Titan, but the loss in thrust compared to the Rhino is noticable. Gordon's P180 gave it a bit more top speed and more vertical from low speed (such as takeoff), but the added thrust wasn't always usable in maneuvers.

The oly at 50+ pounds and an engine weight of 6.25 pounds will hurt the plane. You will need considerable nose weight to offset the extra 2.5 pounds of engine weight, flight times will be shorter, and the landing gear which are the weak spot on this plane won't like all the xtra pounds. The intakes/pipe probably will not allow you to get to the full rated thrust. And you will very rarely have the stick at full throttle anyhow because you won't need it. Unless you are a pilot that absolutely gets off on top speed all the time, I would stay away from this engine/airframe combo.