Dipstick interpretation
Posted: 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?
It really looks like most of it is coming out the breather.
Re: Dipstick interpretation
Posted: 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
Posted: Sat Aug 06, 2022 6:35 pm
by Bryan Cotton
Thanks Matt! I actually made a baffle for mine.
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
Posted: 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
Posted: 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
Posted: 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
Posted: 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
Posted: 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
Posted: 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
Posted: 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.
Re: Dipstick interpretation
Posted: Sun Aug 07, 2022 10:33 pm
by Bryan Cotton
So, using Michael’s technique I’m either just at full or a little below. I’m going to fly another half hour when the weather is good.
Re: Dipstick interpretation
Posted: Tue Aug 09, 2022 11:18 am
by Bryan Cotton
Bryan Cotton wrote:So, using Michael’s technique I’m either just at full or a little below. I’m going to fly another half hour when the weather is good.
Half an hour flight - much less oil on the belly. Seems like progress. I took the dipstick out of the hot engine to let the oil drain down and I’ll check it tonight.
Re: Dipstick interpretation
Posted: Wed Aug 10, 2022 11:42 am
by Bryan Cotton
Oil was a little below full. Probably matched the small oil spot on the floor. I’m getting there.
Re: Dipstick interpretation
Posted: Fri Sep 02, 2022 10:37 pm
by Bryan Cotton
I’m not keen on the stock Aerovee dipstick. So I bought a stock VW dipstick:
https://www.ebay.com/itm/172982182261
It works great! But only when the cowl is off. So I got to thinking if I could make an access hatch it would be awesome. I decided to modify the dipstick so I could minimize access requirements. First I made a shim to jam in the handle.
Then I welded it:
Cut the handle off:
Finally I welded an AN3 bolt to it. I ground the cad plate off, of course.
Next up: cowl access.
Re: Dipstick interpretation
Posted: Mon Sep 05, 2022 10:30 pm
by Bryan Cotton
So I put my cowl on the left side. I took a hole punch to a piece of blue tape, and put that over my dipstick sticky side up. Slid the dipstick out of the tube until it hit the cowl, then slid the tape up and stuck it on the inside of the cowl. Hole location defined!
The hole size is big enough to get the dipstick out. There is the stop that keeps the dipstick from going too far into the tube and that is the part that needs to clear.
I used a piece of baffle seal and just riveted it on one side. I’m thinking the air pressure should push it against the cowl. Or, we will get more airflow into the cowl.
Next up: dipstick extender.
Re: Dipstick interpretation
Posted: Wed Sep 07, 2022 12:17 am
by Bryan Cotton
Here is my threaded aluminum dipstick extension:
Re: Dipstick interpretation
Posted: Wed Sep 07, 2022 12:24 am
by BRS
Dress it up a bit by making a plug for the cowl-hole and fix the stick to that plug. Cut it short leaving just enough for a handle.
Re: Dipstick interpretation
Posted: Wed Sep 07, 2022 7:47 am
by Bryan Cotton
BRS wrote:Dress it up a bit by making a plug for the cowl-hole and fix the stick to that plug. Cut it short leaving just enough for a handle.
I had considered that, but the engine moves and the cowl doesn’t. The extension only goes on to check the oil.
Re: Dipstick interpretation
Posted: Wed Sep 07, 2022 1:10 pm
by Area 51%
I also went with the stock VW dipstick for ease of reading. To get the stick in and out, I drilled a hole similar to Bryan’s, but added a slot to it long and wide enough to allow passage of the completely stock stick.
Didn’t think to add the flap to keep the air in…Next time.
Re: Dipstick interpretation
Posted: Wed Sep 07, 2022 7:10 pm
by Bryan Cotton
Area 51% wrote:I also went with the stock VW dipstick for ease of reading. To get the stick in and out, I drilled a hole similar to Bryan’s, but added a slot to it long and wide enough to allow passage of the completely stock stick.
Didn’t think to add the flap to keep the air in…Next time.
I had considered that as well - and went with what I presented.
So when is next time scheduled for?
Re: Dipstick interpretation
by Area 51% » Thu Sep 08, 2022 9:06 am
Going to start the next project on the first…the first chance I get.