Topic: Oil Level

[David H]

Where do you folks like to keep your oil level?   With my bonanza, I kept the oil level around 9 quarts.   The maximum was 10 but that tenth quart was gone in an hour.   It just went out the breather. That engine, an IO470, had a wet sump.   After that tenth quart flew away, it stayed at 9 quarts for the next 10-12 hours flying time.    With the Gipsy Major, we've got a dry sump and an oil tank.   I had read somewhere that the Gipsy will also tend to dump out extra oil fairly quickly.   I had bought into that theory but now I'm not so sure.    Wouldn't any excess oil simply be pumped back into the tank and not dumped overboard.   The engine only gets the oil it needs from the pump.     I've been keeping my oil level around an inch or two above the halfway mark.   I'm wondering if I should try to keep it higher or lower.   
Thanks
Dave

[john henderson]

We run at between the half and three quarter mark, generally just above half.  Anything above this seems to leave the aeroplane fairly quickly.  Howver, in hot weather nearer the three quarter mark.  If we are doing a long flight- e.g 1.5 hours then three quarters full - just in case.

I agree with you that logically since it is a dry sump tank, oil level ought not to be relevant, but our expereience over a number of years suggests that a high tank level increases consumption!  Maybe crank case pressure and a fulllish tank drives oil up the vent pipe and out of the breather.

[Fitzy]

I am with John on this one.  We run ours between half and three quarter full and use about 1 quart every three hours.  Filling the tank up seems to lead to more going out the drain box.  Hopefully someone will have a technical explanation!

[kenkelso]

The reason it dumps oil out of the breather is that it comes back from the engine scavenge pump frothy and therefore takes up more room. We keep ours just above half unless on a long leg (2 hrs)

Ken G-BWMX

[Rod Blievers]

Thank you Ken for that simple yet intelligent explanation. I too have pondered about "the more you fill, the more you lose" characteristic. Possibly I keep mine too full, justifying it on the basis of operating in  higher temperatures than the UK guys are used to. I always keep at 3/4 minimum and seem to use at a litre in 90 minutes.

Cheers,

Rod.

[Bronco]

I've had my Chippie (WP904) for about three years now. I have never been around another one so don't know about measureing oil. My oil cap has no extension into the oil. Is an extension missing? Where are folks reading the oil level?

[Bob]

It certainly should! I'll try and get a photo

[proplover]

Bronco - Eeeeeek!!!!

There should be a metal rod of around 6inches attached to the oil cap with markings on it, as you screw the cap onto the tank the rod goes into the tank.

[Bronco]

I've owned aircraft for many years and they all had dipsticks. The Chipmunk is a different critter. My first surprise was the need for Whitworth tools.
Back to the dipstick. How does it attach to the oil tank cap?  Could it have become detached (not broken off) and be in the oil tan?
If someone can give me a picture with some measurements I'm sure I can make one. 

[Bob]

Here you go, We have the larger oil filler .There is a small hole one too. The dipstick goes into the cap and is retained with a split pin. I dont have one in stock but could find one...

[Bob]

Michael may have one from his right off...

http://www.caledonianchipmunks.co.uk/forum/index.php/topic,846.0.html

[Bronco]

Bob

Thank you very much for the pictures and measurements. If you have an orginal dip stick extension I would perfer to keep the bird orginal. Are you in the states?
With the information you gave  I could  also make one.   I think I do have the large oil tank cap. My cap must be close to three inches in diameter. Thanks again.

[Bronco]

I guess the next thing I need to know is the material used in the dip stick. It appears to be brass. I'm still wondering if mine may have come loose and be in the oil tank. If the material used can be picked up with a magnet then I'll go fishing. If I can't catch anything I'll get on the lathe.

[john henderson]

Yup its brass!  You knew it would be!  Suggest drain tank and then go fishing with flexi grip or use flex light to look inside. 

[proplover]

Id be worried that it was in the tank somewhere!!!! At least you've got the large tank neck to work with, ours is the pre-mod small one!