I finally got the top overhaul (1) of my Continental O-200A done (new cylinders, pistons, valves, …) and am now breaking in the engine.
I did two test flights of 1 hour each. I didn’t get any instructions by the engine or repair shop, and unfortunately I don’t have the operator’s or maintenance manual for the O-200.
Did I do this right?
Also, unfortunately, I leaned a little on take-off and the brief climb (2-3 minutes) — that shouldn’t be a problem for the break-in, right?
Thanks,
Michael
(1) See this thread for background info.
After a recondition, and again after a top overhaul with 2 new piston-cylinder kits, from memory, I was told to take-off, climb at a shallow angle at high cruise revs, and fly at 3000’ for as long as I could, watching the oil temperature – the only temp gauge on our O200.
Straight oil. There was a little ground running to test, but for the first flight it was as little time on ground as possible.
The current Lyco break-in instructions are here.
These should be followed, because if you glaze a cylinder (even just one) you will be looking at a high oil consumption for perhaps well past 100hrs; in some reported cases indefinitely until the cylinders are removed and re-honed. Here is a thread on a possible solution to glazing, but it is really for the brave
And how important are the first 1-2 hours vs. the following 10-15 hours for the break-in?
In hindsight, I probably didn’t follow the instructions perfectly during these first two flight hours (climbed pretty steeply for about 5-10 minutes with some leaning / used 2500-2550 rpm in cruise, which might be a little too low / needed to taxi 10 minutes longer than ideal for get fuel).
Could this already affect break-in?
It is critical that the first 1-2hrs are flown at a high power, as specified.
If you fly it at say 50-60% then you will glaze cylinders. Don’t ask me how I know For a non-turbo engine, it means no Eurocontrol IFR flights because FL080+ means too-low power.
Any idea how much power is 2550 rpm corresponds to for the O-200A at 2500 ft and 10 degrees C? (I have a climb prop, so speed is only 185 km/h at that rpm with my Jodel.)
looks pretty much ok what you did. The important bit is not to baby the engine but to fly high cruise, which in the case of a O200 mostly means full throttle. Thereafter 75% for the first hours till the 1st oil change.
Honestly I don’t know whether it was that good.
In the first operating hour:
So in the first operating hour, about half an hour was probably spent taxiing or in low-rpm descent. :(
Sorry if I sound like I’m going a bit crazy on these datails, but I’m honestly quite traumatized from all the trouble I had with this airplane since the day I bought it. (And I spent about the purchase price just in fixing it up.)
I would hate to have a failed break-in out of ignorance / lack of instructions / stupidity.
I’m also very surprised that the first 1-2 hours are crucial for the break-in. Why is that the case? I thought it was a 25-50 hour process …
Zorg wrote:
I’m also very surprised that the first 1-2 hours are crucial for the break-in. Why is that the case? I thought it was a 25-50 hour process
As far as I understand the first few hours are the really critical ones. My club did the break-in of two Lycoming engines this year. Lycoming’s Service Instructions call for high and alternating power settings the first 2-3 hours, including 30 minutes at full throttle. After that, the engine should be run at 65-75% power “until oil consumption has stabilised”. There is no mention of 25 or 50 hours, but it is not so easy to determine exactly when “oil consumption has stabilised”. I guess the recommendation of operating at 65-75% for 25 or even 50 hours is to make absolutely certain that oil consumption has become stable. On the advise of the CAMO, we ended the break-in period on one of the engines after about 30 hours with no ill effect.