How can one detect a broken piston ring (high oil consumption)?

I´d have expected you do your high flight level climbs at about 80 percent max revs as compared to 60 to 55 percent in cruise. So oil going out the exhaust should be quite a bit more at higher revs for one hour. Doing a lot of take offs may also contribute to higher oil bills than easy cruising for hours. Anyway, an oil leak somewhere on the engine should be easily traceable, and if so, in doubt, do a good wash down and only do a half hour flight before carefully checking the engine compartment again for the leak. Vic

Aviathor wrote:

It sounds extremely high to me. Have never seen more than 1 l in 10 hrs. On my trip to Norway past summer I flew in excess of 20 hrs and did not even add oil. It was 7 qt when I left and still above 6 qt upon my return. IO360 A1B1 (?)

It may seem high compared to 1 anecdotal example, but in fact is closer to “normal”, and still well under what the manufacturer calls excessive.

vic wrote:

I´d have expected you do your high flight level climbs at about 80 percent max revs as compared to 60 to 55 percent in cruise.

Ern he said NA, so even with the balls-to-the-wall, by 5,000’ feet your’ already under 80% power but only 1/8 of the total time to climb to FL200.

I said 80 percent REVS, not power, meaning, at high revs you usually see higher oil burn than at cruise revs. just an idea …. Vic

vic wrote:

I said 80 percent REVS, not power, meaning, at high revs you usually see higher oil burn than at cruise revs. just an idea …. Vic

OK, but the problem the OP is dealing with here is with cylinder rings and the problem at lower power or precisely low MP is the lack of cylinder pressure to seal the rings.

I am with Michael on this one. Also the majority of the climb time is at 60% power or less. How much time to climb to FL100 power 100%-60% ad how much Time from FL100-FL200 60% -40% power. It might be even less power. By the way what does you MP show at that altitiude Peter?

By the way till my #5 started burning oil I was getting 1qt/15 hrs That was for 850hrs of flying.

C210_Flyer wrote:

I am with Michael on this one. Also the majority of the climb time is at 60% power or less. How much time to climb to FL100 power 100%-60% ad how much Time from FL100-FL200 60% -40% power. It might be even less power. By the way what does you MP show at that altitiude Peter?

It’s a little bit higher. An NA engine at WOT gives you about 70% power at FL100 and should give you in the order of 45% at FL200.

Just for fun, I made a quick estimate of the average power for a one-hour climb to FL200, assuming a linear decrease in ROC with altitude. It would be about 60%.

When it comes to oil burn I do not believe there is a relation to power. I think it is the high rpm setting that will be noticed later in the oil consumption. It is the number of four stroke cycles that the engine does in one hour: One hour of max rev does twice the cycles than one hour at 50 percent revs , so you should have about twice as much oil gone through the exhaust compared to one hour at half the revs – logic ? Vic