I did the third oil change in the IO-550 Legacy and here are the issues I've had in the past 140hrs:
Small problems and fixes:
Both front and rear tabs on the pax top aluminum baffle shelf (goes across #5 #3 #1 cylinders) that hold the aluminum vertical baffle holder broke off.
Cylinder #5 is hottest, and is cooled better by cutting a hole in aluminum behind the alt. (get below the thinnest part of the cylinder fins)
Cylinder #2 is next hottest, air is again stopped at the thin fins, this time by the oil cooler box. cut a hole in the oil cooler box so air can flow
around the cylinder.
Starter adapter slipped on hot starts and was replaced under warrantee.
Oil vernatherm broke and was replaced under warrantee.
Rudder cable to push rod assembly became sloppy and was removed and rebuilt with more parallel surfaces decreasing 90^o offset free play.
Had to repaint wing leading edge from rain damage.
Rob Logan bad modifications:
Center tank vent issues
Gap everything before paint... lots of gap, paint is thick!!! (popcicle stick gap everywhere)
Com antenna switches impose an unacceptable line loss
Remote oil filter on engine shakes too much.
Cowl ram air blows / cools #4 and I'm not convinced the net effect was worth the effort.
Oil air separator into oil holder, overboard or into cylinder head, remains a question.
Two 100 watt landing lights need big wires and +20amp breaker.
My electoral design overloaded the "second" alternator, so I moved all lights to the primary alternator.
The new hyd pump (gear up in 3sec rather than 6sec) is very cool, but required larger relays & wire. (load is really 35 amps, even tough its rated at 70 amps @12v)
Rob Logan bad fixes and pictures:
Hot start is old news to most of you, but this is the process I learned from an ovation driver and works well in the Legacy:
Push throttle, prop, and mixture full forward high boost for 5sec pull throttl full back and then forward 1/4" start (with cross tie)
Push prop, and mixture full forward, pull throttl full back and then forward 1/4" start (while slowly advancing the throttl) as soon as it fires: low boost work the throttl back to idle low boost off, if failed to start, prime like cold, but only 3 sec
After 4 of above:
Pull throttl and mixture full back high boost for 30+ seconds go to hot start process.