Im putting this engine on the nose of my showtime 50 to replace my 55ax. Does anyone have any expierience with this combo or with the engine in a 6.5 - 7lbs 3D airframe? Im also wondering what a good prop would be for this engine.

Thanks in advance,
Joe

I had a ST 90 on a Pizzaz. The verticle was unreal. It's not a great 3D plane to start with but it was fun. I would run a 13x6 or 12x7 for instant spool up.

David

The ST 75 is a strong engine, but also heavy. I would start around 12 or 13 X 4 and see if it will hang and pull out well. I have no experience with that airframe, good luck!

I would start with a 14x4 Xoar or APC sport (not W).

I hope it will punch out of a hover. I was going to put a st 90 in it but i read that the mid range is slugish and I wont be flying this airframe at full throttle with that big of an engine. So i settled with the st 75 hoping that fuel economy would be better.

St-75
Hp - 2.2 at 16,000rpm
Weight - 20.6 ounces w/o muffler.

55ax
Hp - 1.75 hp at 15,000 rpm
Weight 15 ounces ( I think ) w/o muffler.

Anyways more opinons are welcome.

Thanks,
Joe