100 hours
Posted: Sun Sep 24, 2023 10:58 amThis past week I hit 100 hrs on my 912 powered Onex. It started out as a stock 80 HP engine, and I later upgraded it to about 95 HP with 912S cylinders and pistons (reduced to 9:1 compression). I get an average climb in excess of 1100 fpm from 1000-4500 ft, and about 1300 fpm initially. Easy cruise is 140 mph at 4.5 gph, and 150 mph at the max allowed continuous RPM of 5500. The engine has been well behaved, and the only issues I really had are cracking exhaust pipes. I think I've got that fixed finally with enough stainless ball joints.
The cowl will be a works in progress for as long as I can put off having to fill/sand/paint it :-) The temps have never been an issue, despite doing a few things against the common practice. My oil cooler is sealed against the back of the radiator, and I'm using a very inefficient scoop. The max temp I see is 220F for oil and cylinders, and that's in a long climb when the summer temp is over 90F. At this point the scoop is still just bolted on, which has allowed me to try a number of different sizes and shapes. I could even keep it that way to have a summer and winter scoop.
The airframe itself has been trouble free, though the main gear is starting to show signs of spreading after about 200 landings. I've got an email into Sonex about that now. Since I only have 4.5" of prop clearance in level attitude with my 60" prop, I can't afford to lose any more. I never do conventional wheel landings to minimize the risk of a prop strike, and because I've never found them to be necessary or desirable in any plane I've owned. Full stall landings aren't possible due to the short main gear, so all landings are sort of tail low wheel landings.
The cowl will be a works in progress for as long as I can put off having to fill/sand/paint it :-) The temps have never been an issue, despite doing a few things against the common practice. My oil cooler is sealed against the back of the radiator, and I'm using a very inefficient scoop. The max temp I see is 220F for oil and cylinders, and that's in a long climb when the summer temp is over 90F. At this point the scoop is still just bolted on, which has allowed me to try a number of different sizes and shapes. I could even keep it that way to have a summer and winter scoop.
The airframe itself has been trouble free, though the main gear is starting to show signs of spreading after about 200 landings. I've got an email into Sonex about that now. Since I only have 4.5" of prop clearance in level attitude with my 60" prop, I can't afford to lose any more. I never do conventional wheel landings to minimize the risk of a prop strike, and because I've never found them to be necessary or desirable in any plane I've owned. Full stall landings aren't possible due to the short main gear, so all landings are sort of tail low wheel landings.