Oil usage/burn

[Trippster]

Ok, this may be very fortunate for me, but we use/burn almost no oil at all. We flew 6 hours to OSH and 6 hours back and an additional 2.5 hours and still have not needed to add oil. In fact, it still shows 8 quarts on both engines barely at all below the line.

Is this normal? Are we just very fortunate or what? It just seems to me that we should be needing to add oil more often, but I'm thrilled that we don't. In the last 120 hours, we've only added about 1 quart a side between changes or about 1 quart every 25 hours.

Thanks,

Tripp

[mshac]

My front engine is like yours. I think I added two qts over the last 25 hours. The rear engine though is another matter, due to leaks.

[TomM]

My rear engine is coming out in November due to all the leaks. Have replaced the oil filter adapter with a Wolf remote filter which did make a big difference. Also replaced all the push rod tube seals and valve cover gaskets several times and removed the unfeathering accumulator - all of which were leaking. As bad as it sounds, I have cut the oil leaking "down" to a quart every 5 hours....makes a mess of the engine compartment, rear cowling and stab.

It is wet about everywhere and since we have done all we can with the engine in the air frame it is time to pull it and replace everything short of splitting the case. It is not wet on top or at the crank seal - just everywhere else

Front engine is better by over twice that of the rear engine.

So consider yourself lucky to not lose any oil!!

[edasmus]

"Is this normal?"

From my experience, the range on "normal" oil consumption is quite wide. I would guess, and this is truly a guess, that your oil consumption being as low as it is, is likely way lower than most engines out there. There is certainly nothing wrong with your engine in that regard. You could probably look up the maximum usage allowed by Continental for our engines. Off hand I do not know what that is but it is quite high. It might be on the order of a quart every two hours or so. I think that is what Lycoming recommends also. It might vary with the engine model also.

I just had both my engines overhauled in the last year at Poplar Grove Airmotive. My old front engine was consistent at a quart every 7 hours and the old rear was a quart every 9 hours. The overhauled front engine has settled on a quart every 10 hours and the overhauled rear engine was placed into service a week ago and has 6 whole hours on it so it's consumption is to be determined. In those 6 hours it appears to have used a half quart, most of that occurring on the first hour.

More important than the consumption of oil would be a CHANGE in the consumption of your oil. Whatever your number is, if that is remaining consistent, then it is a reasonable assumption that no dramatic changes have occurred on the innards of your engine.

Having said all this, my old front engine showed no sign of any change right up until the flight that a couple of rings broke and a chunk of the number 5 piston went out the tail pipe. That flight lasted about 30 minutes after the failure and my oil consumption in that 30 minutes jumped to 6 quarts per hour. Yes, it was down 3 quarts in the 30 minutes it took me to get down. The engine was running fine 99% of the time with occasional momentarily roughness.

If anyone is wondering why it took so long to get down, I was gathering data from my JPI so I could have something useful to say to my mechanic besides "every once in awhile, the engine starts shaking."