David-aviator
Well Known Member
There is a post today about when it may be safe to leave the traffic pattern, the concern being whether or not the engine is OK after 5 hours of boring holes doing the break-in procedure.
As I understand it, the break-in period is running the engine hard to properly seat the rings. If oil blows by the rings before they are seated, the cylinders could glaze with burned oil and the only cure is to disassemble the engine and hone the cylinders to remove the glaze.
My last Lycoming was a 0360-A4M on first run. It was flown about 60 hours on a newly certified aircraft and then overhauled when it hit 2000 hours by Blueprint Aircraft Engines . Blueprint is the company founded by Ed Rachanski Sr., the guy who also caused AvBlend to be certified.
At the time Blueprint had a policy of inviting customers to observe the tear down, which I did. In the process, I asked about the break-in procedure for the new cylinders. They showed me the new Millenium cylinders and said, feel the inside of the cylinder with your finger nails, you can feel the ridges. We hone them before assembly, there is no break-in procedure, just go fly the airplane. And that I did with no problems whatever. The aircraft and engine have since been sold to a friend who flies it very much, also with no problems.
I do not understand why owners of new Lycoming engines, and the clones, have to go through the ritual of seating the rings when it is so easy to not have to do that. What these guys at Blueprint did is very simple and not at all time consuming. I really appreciated it.
David Domeier
Troy, Mo
RV-7A
Currently flying with a Subaru H6
But still in the Lycoming loop
As I understand it, the break-in period is running the engine hard to properly seat the rings. If oil blows by the rings before they are seated, the cylinders could glaze with burned oil and the only cure is to disassemble the engine and hone the cylinders to remove the glaze.
My last Lycoming was a 0360-A4M on first run. It was flown about 60 hours on a newly certified aircraft and then overhauled when it hit 2000 hours by Blueprint Aircraft Engines . Blueprint is the company founded by Ed Rachanski Sr., the guy who also caused AvBlend to be certified.
At the time Blueprint had a policy of inviting customers to observe the tear down, which I did. In the process, I asked about the break-in procedure for the new cylinders. They showed me the new Millenium cylinders and said, feel the inside of the cylinder with your finger nails, you can feel the ridges. We hone them before assembly, there is no break-in procedure, just go fly the airplane. And that I did with no problems whatever. The aircraft and engine have since been sold to a friend who flies it very much, also with no problems.
I do not understand why owners of new Lycoming engines, and the clones, have to go through the ritual of seating the rings when it is so easy to not have to do that. What these guys at Blueprint did is very simple and not at all time consuming. I really appreciated it.
David Domeier
Troy, Mo
RV-7A
Currently flying with a Subaru H6
But still in the Lycoming loop