pa24-250 oil consumption

[Brad Birdsong]

I have a 1959 Carburated 540, pa24. If I fill the engine with 10 quarts oil with a new oil filter and run the engine three hours I am down to seven quarts. The oil remains clear and no metal in oil filters. Also, no belly blow or blow by in air filter. I have a new air oil seperator. Good compresion and no high oil temps. very odd. Engine runs great but can't figure out where the oil is going. It levels out at seven quarts and will run for a long time at that level. Can someone messure there dip stick length so I can make sure I have the correct dip stick. Any suggestioins or ideas on this problem?
Thanks, Brad

[Ray B]

Hey Brad, My '60 250 does the same thing! So I only put in 8 qts after oil/filter change. Ray B

[Brad Birdsong]

Thanks Ray. I am an Automotive Mechanic and this kind of thing drives me crazy. Watching the oil pressure real close.

[Ray B]

Brad seven quarts of oil in the 0-540 is plenty. The minimum is down around 3 qt .( and remember the filter holds nearly a quart that does not show on the stick). Next oil change put in 5 qt and ck the dip stick. Then 1 qt at a time to ck for accuracy . If it's not reading correctly let me know and I'll measure mine, might even have an extra dip stick in the shop. Ray B

[N3322G]

Brad,

FYI on my twin the dipstick goes to 8 qt, minimum is 2 qt. After an oil change I put in 6.5 qt per side which yields 6 on the dipstick due to new filter filling. Then I regularly keep the oil at 6. Works great. I know it is not the same engine but it appears to be a similar issue. This has been working for 41 years.

[Brad Birdsong]

The 250 runs too strong to have a seriousproblem. Just spent 45k on it so I hope the engine is still ok. Thanks for the posts. I'll update as time goes on. Still, oil does not evaporate.
Brad

[steen]

No, but it does vaporize.
Lycomings do this and it is normal. The 320's hold 8 qts. but in real life you add at 5 and keep it around 6....any more and it goes away. With the 540, add at 6 or so to keep it
around 7 and the engine is happy.
Oil levels above this get beat into a froth by the whirling crankshaft in the crankcase and gets vaporized and burned or put out the breather as vapor in short order.
On oil/filter changes just put in 8 qts. and add when it gets down to 6.....your engine will love you.
Steen