Ervine 53 prop?
The irvine is sweet!
With the APC 12.25-3.75 the engine held my h9 ultra stick in a hover @ 3/4 throttle over 5800 feet fo elevation. This plan is a PIG! over 6lb. the funny thing is, It died today when a snaproll brokeoff the elevator and it went in from 75'
Good thing it's been raining for the last three days, the engines fine! but I dug it out of a 6" hole in the ground mostly wood chips.