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Dipstick interpretation

PostPosted: Sat Aug 06, 2022 5:34 pm
by Bryan Cotton
So after dumping oil all over the Waiex belly on my last flight, the dipstick still reads full. I'm thinking I just overfilled it by a gallon or two and it will slowly dump out the breather. Anybody have relevant experience?
oil streak.jpg

It really looks like most of it is coming out the breather.

Re: Dipstick interpretation

PostPosted: Sat Aug 06, 2022 6:17 pm
by sonex1084
Here is what I have been told. The cam sits under the breather plate. As the cam rotates, it throws oil up through the breather tube. A normal VW has a metal louvered gasket to help prevent the slush of oil from the cam, but AeroConversions says not to use it. I don't know if what I relayed to you is factual, but I know it makes sense to me. I have my dipstick marked at 2 qts, 2.5 qts and 2.75 qts. The space between the 2.5 qt mark and 2.75 qt mark is small while the space between 2 qt mark and 2.5 qt mark is much larger. It takes much more used or missing oil to register a drop between 2.5 and 2.75. A couple more flights and you will probably notice a difference.

Matt

Re: Dipstick interpretation

PostPosted: Sat Aug 06, 2022 6:35 pm
by Bryan Cotton
Thanks Matt! I actually made a baffle for mine.
Image

This is from page 112 of my thread:
viewtopic.php?f=39&t=578&p=38208

I only marked 2.25 and 2.75 qts as per the manual. So it sound like if I blow out some more, I'll actually see a reasonable level on the dipstick.

Before the second flight, the oil was at the top of the squashed tube, a little higher than my 2.75 qt mark.

Re: Dipstick interpretation

PostPosted: Sat Aug 06, 2022 6:43 pm
by GraemeSmith
You are wiping the stick first? And waiting for the oil to fully drain down AND COOL before dipping? (Sorry - gotta ask).

Then:

Pull out stick
Wipe Clean of oil that was drawn up tube by capillary action/or cooling
Insert stick and immediately withdraw.
Read.

--

I'm coming to the conclusion that my Aerovee is "sweeter" at 2 1/2 quarts. If I put in the last bit to bring it up to 2 3/4 - it immediately goes overboard via the breather, even with an oil separator to return oil to the engine. Though this observation can be confounded by flying quite a lot of acro which can/or doesn't chuck oil overboard in baffling ways I have not quite figured out yet...

And it is confounded a little more by my added PEtersen oil filter and pipe work which add another 1/2 quart volume to the system. So in order for the engine to "see" the expected oil level at 2 3/4 quarts - I actually put 3 1/4 quarts of oil in the sump. When that is hot - it is visibly expanded and higher up the dipstick. I have to measure cold for any real comparison.

Re: Dipstick interpretation

PostPosted: Sat Aug 06, 2022 6:47 pm
by Bryan Cotton
GraemeSmith wrote:You are wiping the stick first? And waiting for the oil to fully drain down AND COOL before dipping? (Sorry - gotta ask).

Then:

Pull out stick
Wipe Clean of oil that was drawn up tube by capillary action/or cooling
Insert stick and immediately withdraw.
Read.

--

I'm coming to the conclusion that my Aerovee is "sweeter" at 2 1/2 quarts. If I put in the last bit to bring it up to 2 3/4 - it immediately goes overboard via the breather, even with an oil separator to return oil to the engine. Though this observation can be confounded by flying quite a lot of acro which can/or doesn't chuck oil overboard in baffling ways I have not quite figured out yet...


Graeme,
I have found that if I immediately withdraw the stick, I can't seem to see it. I noticed this when I did my initial calibration at 2.25qt. So I have been doing as you say, except I leave it in for a while and then pull it out to check.

As for the rest - yes. I let it cool for a few hours and I wipe off the dipstick each time.

Re: Dipstick interpretation

PostPosted: Sat Aug 06, 2022 9:45 pm
by gice96
Bryan Cotton wrote: I'm thinking I just overfilled it by a gallon or two and it will slowly dump out the breather.



Wait, a GALLON or two?

Re: Dipstick interpretation

PostPosted: Sat Aug 06, 2022 10:13 pm
by Bryan Cotton
gice96 wrote:
Bryan Cotton wrote: I'm thinking I just overfilled it by a gallon or two and it will slowly dump out the breather.



Wait, a GALLON or two?

Welcome to the forums! If you go back and read my 3710 posts you may get a feeling for my sense of humor.

Re: Dipstick interpretation

PostPosted: Sun Aug 07, 2022 10:00 am
by Scott Todd
That's about the right amount for one flight Bryan. Keep flying it!

Re: Dipstick interpretation

PostPosted: Sun Aug 07, 2022 10:03 am
by XenosN42
This is the procedure I have used.

After a flight I remove the dipstick.
Before the next flight I insert it and read the level.

I think this works well because the oil in the tube has a chance to drip down into the sump. Otherwise you are reading the level in the sump and whatever attaches to the stick as you insert it and withdraw.

Re: Dipstick interpretation

PostPosted: Sun Aug 07, 2022 10:29 am
by Bryan Cotton
XenosN42 wrote:After a flight I remove the dipstick.
Before the next flight I insert it and read the level.

Thanks Michael! I'll try that.