Cylinders replaced

[geneticistx]

Hi there,
we had the cylinders replaced on our O-350 engine and we will be flying for 25 hours on mineral oil. Any performance or other notable approach to breaking in the cylinders for the first 25 hours?

thanks

[TrilliumFlt]

Just curious, are you sure it's an 0-350, I'm only aware of a Lycoming 0-320/0-360 or a Conti IO-360. In either case discuss this with your AME some have very strong thoughts and ideas. However, in general have a read in the relevant engine service manual for the manufacturer and follow its guidelines.

[photofly]

Can't speak for the particular engine, but run it, and run it hard. Minimize idle time on the ground (while still warming the oil), then fly at at least 75% power (leaned) for as many of those 25 hours as you can.

+1 for following the manufacturer's instructions, too.

[TrilliumFlt]

I'll add that if you're doing the brake in now, Fall into Winter a proper pre-heating is a "must do". Is there an installed pre-heating system on the engine, Tanis, Rieff etc. Not only do you need to pre-heat the oil you need to warm the crankcase as well and depending on the OAT this can take some time if it's seriously cold soaked.

[PilotDAR]

If you're flying a break in flight, yes, manufacturer's recommended practices, but probably high power, with as few power changes as possible for the first few hours. Boring as it will be, fly circles around your airport, not a cross country flight. It took me a couple of customer break in flights to figure this out. When you suspect a problem, you would like to be close to home! Through my own lack of forethought on this, I once glided a C 206 30 miles home with the engine at idle power, watching it's instrument indications very carefully, after getting nice clean engine oil all over the windshield. I should have been close to home!

[BGH]

When I broke in a IO520D in our 185 I was briefed by the mechanic before start & pretty much had him do all the checks as we taxied to the runway.
Minimum delay at the hold line.I flew the plane & he flew the engine until the temperatures settled down,we stayed close to the airport in case something came up.
I flew the next 25 hours after that at about 75 or 80%.

Daryl

[geneticistx]

TYPO O-360

[geneticistx]

Thanks to all