OAT for Engine Break-In

[Samir13k]

Hello All,

After a long and painful annual and overhaul, it’s finally time to get the M20G back in the sky. We have been patient for a few weeks now waiting for weather worthy of being flyable, and tomorrow is looking promising. The only problem I’m seeing is that around the 9am to noon window when we plan to be up there, we are expecting the ground OAT to be 8 degrees (F) at 9am and 15 degrees (F) at noon. 

Ive been trying to call the overhaul shop all day to see what their recommendation is (and will continue to do so) but I haven’t gotten an answer or call back.  I wanted to get external opinions as well on whether it was reasonable (or wise) to attempt engine break-in with these OAT’s, or if it’s not a good idea. I will have a far more experienced Mooney CFI with me to assist

The engine is a Lycoming O-360-A1D, with Lycoming OEM Balanced Steel Cylinders

I did have the Reiff XP engine and oil sump heaters installed, so I assume it will be best to plug those in overnight, even if the plane is sitting in a heated shop overnight?

Thanks in advance as always, any and all tips to get the best break-in experience in the M20’s will be appreciated

[Fritz1]

definitely plug in the Reiff, should get everything to 120F, minimize taxi, take off as soon as CHT and oil temp permit, ask the shop if they ran the engine for at least one h, then break in is almost done and nothing to worry about, low temps should help because engine develops more heat during break in, I would stay within gliding range of the field, others will chime in

[hammdo]

I flew mine in the 20s° F last year… pre-heat the engine before going out — we did that and she broke in fine:

-Don

[toto]

1 hour ago, Samir13k said:

Hello All,

After a long and painful annual and overhaul, it’s finally time to get the M20G back in the sky. We have been patient for a few weeks now waiting for weather worthy of being flyable, and tomorrow is looking promising. The only problem I’m seeing is that around the 9am to noon window when we plan to be up there, we are expecting the ground OAT to be 8 degrees (F) at 9am and 15 degrees (F) at noon. 

Ive been trying to call the overhaul shop all day to see what their recommendation is (and will continue to do so) but I haven’t gotten an answer or call back.  I wanted to get external opinions as well on whether it was reasonable (or wise) to attempt engine break-in with these OAT’s, or if it’s not a good idea. I will have a far more experienced Mooney CFI with me to assist

The engine is a Lycoming O-360-A1D, with Lycoming OEM Balanced Steel Cylinders

I did have the Reiff XP engine and oil sump heaters installed, so I assume it will be best to plug those in overnight, even if the plane is sitting in a heated shop overnight?

Thanks in advance as always, any and all tips to get the best break-in experience in the M20’s will be appreciated

The only concern I would have is about minimizing ground run time with below-freezing OATs.  If this is the first run, definitely get it as warm as possible with your preheat.

Not sure about taking a passenger on the post-mx flight.  Check 91.407(b).  I've always done these solo.

For initial break-in flights, I orbit the airport at 2500' AGL for the first hour, then land and inspect.  My understanding is that about 90% of the break-in happens in the first 20 minutes or so.  Those early minutes are critical.  Your steel cylinders will take ~10 hours for the CHTs to settle.

[Fix]

I would make sure to Pre-Heat engine properly and the make sure that my Oil Temp was around 170-190F when flying and good temps on CHTs.

 

[Samir13k]

Thanks everyone. Aircraft is in the MX hangar and will be plugged in to preheat overnight as well. Looking forward to finally flying after a few months. Will have a very seasoned Mooney pilot do the initial flight.

4 hours ago, Fritz1 said:

definitely plug in the Reiff, should get everything to 120F, minimize taxi, take off as soon as CHT and oil temp permit, ask the shop if they ran the engine for at least one h, then break in is almost done and nothing to worry about, low temps should help because engine develops more heat during break in, I would stay within gliding range of the field, others will chime in

Watson Aero’s site says they run the engines 60-90 minutes on a test stand prior to shipping the engine out

• Finally, to ensure the engine will perform better than new and meet our high standard of quality, we test it thoroughly on our in-house test cell. Our testing helps to ensure correct piston ring seating, and measures engine RPM, temperatures, and pressures so we can confirm the performance and conformance to Factory standards. Each engine receives an average 60 to 90-minute test run.