VAF Forums

VAF Forums (https://vansairforce.net/community/index.php)
-   Traditional Aircraft Engines (https://vansairforce.net/community/forumdisplay.php?f=21)
-   -   What happens if you don't change your engine oil? (https://vansairforce.net/community/showthread.php?t=149804)

g zero 05-24-2017 07:51 PM

Oil
 
At 25 hours I'm down a quart and a half . Instead of adding I pump out the remaining 5-1/2 quarts and refill with 7 Fresh . At 50 hours it gets drained , screen checked and new filter . Cheap way to have fresh oil constantly

Mel 05-24-2017 07:57 PM

You might try running at 6 qts. instead of 7. Many engines throw out a quart if over 6.

chrispratt 05-24-2017 08:05 PM

Quote:

Originally Posted by Mel (Post 1175319)
You might try running at 6 qts. instead of 7. Many engines throw out a quart if over 6.

They're called Lycomings, Mel :-)

Years ago I spoke with a friend who worked sales for Lycoming. He told me to run the engine between 5 and 6 quarts. Anything above 6 will get thrown out. That was 10 years ago. I've run the engine between 5 and 6 ever since. I add a quart about every 13-15 hours to get back to 6 qt. The belly stays pretty clean.

Chris

YellowJacket RV9 05-24-2017 08:24 PM

I have to add 7 qts to an empty sump to get to the 6 qt mark on the dipstick. But, anything over that does indeed end up on the belly, so I don't fill beyond that mark.

Chris

g zero 05-24-2017 08:28 PM

Oil
 
Quote:

Originally Posted by Mel (Post 1175319)
You might try running at 6 qts. instead of 7. Many engines throw out a quart if over 6.

I agree with that

Mines an angle valve , holds 8 . I never fill it passed seven .

nigelspeedy 05-25-2017 01:34 PM

Absoulute value limits for contaminants?
 
Anyone have any absolute values that can be used as limits for the various contaminants in Lycoming engines?

Cheers

Nige

ccrawford 05-25-2017 07:51 PM

Have you looked at Lycoming SB 480F?

lr172 05-25-2017 10:43 PM

Your engine is producing a pretty stable amount of metal. Each healthy engine will make a certain quantity of metal per hour due to wear, variable on factors, such as RPM, load, number or starts per hour, etc.

You should to expect to double the quantity of metal in your oil if you double the run time on the oil. It's not that the extended usage interval caused the metal wear, but that the oil was there twice as long to collect the metal the engine was producing. Your engine produces about 1 PPM of iron per hour. Therefore, a 25 hour interval will show ~25 PPM and a 50 hour interval will show 50 PPM.

I am not advocating extended oil changes, but not for metal reasons. Generally, it is the fact that lead and soot will, at some point, overload the oil's ability to hold it in suspension and it will deposit the excess in the engine as sludge once you reach this saturation point.

Larry

BCP Boys 05-26-2017 05:44 AM

duration of time
 
You also have to consider how long does it take you to fly 25 or 50 hours. I've easily flow 25 hours in a couple of weeks at times and at other times in the past when I flew a gas guzzler and fuel was $7 to $8 per gallon, I flew 25 hours in a year.... Obviously the time span has to be considered.

turbo 05-26-2017 07:05 AM

Quote:

Originally Posted by YellowJacket RV9 (Post 1175324)
I have to add 7 qts to an empty sump to get to the 6 qt mark on the dipstick. But, anything over that does indeed end up on the belly, so I don't fill beyond that mark.

Chris

sounds like the 6 qt mark is actually the 7 qt mark now. :eek:


All times are GMT -6. The time now is 05:21 AM.