Oil Consumption and Breather Tube

[Bill.Peyton]

Now that I have around 45 hours on the engine I still find that I am consuming around 1 qt every 7 hours. I have been topping the oil off at 10 quarts. I am thinking that I may be running too high an oil level.
I ordered one of the air/oil separators, but I am now thinking that I don't want to install it until I find the root cause of the problem.
I am also concerned with the angle of the breather which is pointing forward per the plans.
What experience is out there regarding oil level and consumption and breather tube installation on the 540 D4A5?

[aerhed]

Bob, you'll have a lot better luck at 7 or 8 qts. I usually run them at 7.

[Strasnuts]

Bill, I can't remember if you asked me this question a little while ago but someone did and now I am paying closer attention to my oil consumption. When I change the oil I put in 10 quarts. I have 2 quarts extra from the case and I usually have 0 quarts by 50 hours. At about 20 hours I show 9 quarts so I add one more at 25 hours and let it come back down to around 9 to 9-1/8 before the oil change is due again. It seems like 9 quarts is the magic number for me.
So I guess I use 1-1/4 to 1-3/4 quarts per 50 hours holding it close to 9-1/8 total.
As far as the breather tube goes, I like how mine works. It faces forward and shows a dime size drip on the hangar floor after sitting from 1 night to whenever. It seems to work fine and there is no oil residue on the firewall, however, there is a little residue on the louvers. Not saying this is good or right just another point of reference.

[N15JB]

At oil change I fill to 8 qts. and by 25 hrs. I am at 7 qts. or a little less. Oil temp and pressure have been great all summer. I started out filling to 10 qts. but spent a lot of time cleaning the belly. I have a clean belly now, as my wife will attest.

Jim Berry
Rv-10

[RV10inOz]

We run around 7, and fill up at 6.

10 hours per Qt.

Your results are normal.

[10builder]

I'll second the comments above. For the IO-540, anything above 8 quarts ends up on the belly of the aircraft. I don't think I even add any between oil changes anymore, which equates to about a quart and a half every 25 hours.

Brian Sutherland
N104BS (s/n 40308) 485 hours

[Wally]

I managed a flying club for 25 years and for 14 years, we had a Beech Sundowner with an 0-360K engine. It would not retain over 5 1/2 qts.

Had one pilot check the oil prior to a cross country flight of around 200 miles. Found it low and added until it was up to 8 qts. Half way back he stopped for fuel and found the oil was down to 6 qts. He called me in a panic! Asked him to check the belly of the plane as he would find two qts located there!

Three hours on an 8 qt fill up and it would be down to 5 1/2 and remain there, sometimes until time to change the oil.

This was the first engine that I had experienced this with. Our mechanic told us that every engine has a "sweet spot" and will not retain much over that amount.

Wally
RV-4 prepping for paint

[rocketman1988]

Agree with that, my current 172 holds 8 but anything over 5 ends up on the belly...

[N42AH]

Given all the conversation of where to maintain the oil level so it won't be "overfilled" and blown overboard. Here is my question for those that do have an oil air separator. I for example run my O360 at 6 quarts, if I had an oil air separator installed and ran it at 8 quarts would the oil air separator work such that the extra 2 quarts that would be normally blown overboard, be returned to the engine or would some of it be blown out no matter what?

My thinking is that having the 2 additional quarts available for the engine would be a good thing.

I have been considering getting Anti Splats Oil Air separator. What is your experience if you have this oil air separator?

[Ron B.]

I have an oil seperator on my 0-360 and my opinion would be no. It helps but if you were to put 8 qts you would still lose some.