Aerovee Dip Stick

[Onex107]

Do any of you have a problem reading the oil dip stick? I can take the reading three times and it's different each time. I now take it out, to break the vacuum, put it back in, rotate it four of five times to get the oil level to settle down to the sump level, then take at least two readings. It will still measure higher on one side than the other. Have you changed the stick? Do you take it hot or cold? what level do you run? Are you returning the blow by oil to the sump? Do you use oil? If so how much an hour? I don't have this problem with my C-150 because the tube is much bigger in diameter.

[mike.smith]

Do any of you have a problem reading the oil dip stick? I can take the reading three times and it's different each time. I now take it out, to break the vacuum, put it back in, rotate it four of five times to get the oil level to settle down to the sump level, then take at least two readings. It will still measure higher on one side than the other. Have you changed the stick? Do you take it hot or cold? what level do you run? Are you returning the blow by oil to the sump? Do you use oil? If so how much an hour? I don't have this problem with my C-150 because the tube is much bigger in diameter.

I can't get a descent reading when accessing the dipstick from the cowl inlet opening. The oil scrapes itself off the dipstick as I raise it and pull it forward. If I really need a good reading I have to take the top of my cowl off (mine is split horizontally). And even then I can't seem to read the front side of the dipstick, only the back side. Weird. Usually I'm checking the oil cold, before startup. I do return my oil through an air/oil separator and back into the valve cover. I have a catch can just in case something backs up, but I have never had any oil make it to the catch can, so every drop is going back to the engine case.

[gammaxy]

I have the same problem reading my dip stick. I think I can get a pretty good reading using a piano hinge pin. The thought has crossed my mind to drill a hole through the cowl just big enough to insert a piano hinge pin directly into the sump for more precise measurements.

[Sonex1414]

I feel your pain. I was thinking that I was the only one with this problem. I would check the level by pushing the dip stick all the way down onto the dip stick tube and pulling it out and checking it. It would read 1/4 inch low. I would put it back in and leave it for 30 minutes and check it and it would read full. What I surmise is happening is that because the dip stick cap is so tight on the dip stick tube is that is by pushing the cap down all the way, it creates enough air pressure to push the oil down the tube about 1/4 inch. What I do now is just put the dip stick in until the cap touches the tube and check the level and add 1/4 inch. At the last oil change I put in 2.75 quarts and the above method correlates with a full measurement. I am going to use this method until the engine stops.

[gammaxy]

I'm glad there's a few of us too. I've even mentioned my dipstick problems to Sonex. Since I didn't hear anything back, I assumed it was just too ridiculous of a problem to justify a response (this guy thinks he can build an AIRPLANE!??!!?) :-D. It makes it difficult to estimate oil consumption, etc. The only reliable way I know is to measure whatever comes out during an oil change.

I hadn't considered that the difficulty is due to a tight dipstick cap, but it makes sense. Until your comment, I thought it was due to the shape and surface texture of the crushed aluminum tube at the end and considered making my own with a more uniformly textured surface. Piano hinge seems to work repeatably, but that might actually be because of the lack of a seal.

[vigilant104]

I've found that a regular black zip tie (about 8" long and 1/4" wide) makes a good dipstick. It's flat, so there's plenty of surface area to permit easy observation of where the oil line is. It's stiff enough to stop when it hits the bottom of the oil pan. I put a nick in the edge to show me where "full" is.

[Sonerai13]

I've found that a regular black zip tie (about 8" long and 1/4" wide) makes a good dipstick. It's flat, so there's plenty of surface area to permit easy observation of where the oil line is. It's stiff enough to stop when it hits the bottom of the oil pan. I put a nick in the edge to show me where "full" is.

I've used this exact same "trick" myself a few times. This is especially helpful when the oil is fresh and new. New oil is so clear and clean that it is very hard to see on the dipstick. The black nylon zip tie works great for getting a look at the oil level.

Also, be aware that there is a tendency for the oil to "wick" up the dipstick due to capillary action when the engine sits for an amount of time. So when you go to check the oil for the first time in the day, pull the dipstick out, wipe it off, and then wait a minute or two (or more) before actually checking the oil. This will allow oil that has wicked up the dipstick tube to drain back down into the sump, and will result in a more accurate oil level reading when you put the clean stick (or zip tie) back down the dipstick tube.

[Onex107]

An interesting thing I see with my Cessna is, after flying and letting the engine cool off, I think the hot air trapped in the oil filler tube contracts and pulls the oil up the tube, in this case one qt. on the stick. Taken the second time it's a qt. lower. That's a six qt. system.
I think the same thing happens in the Aerovee but I'm not sure how much. That's why I pull the dip stick to "break the vacuum" and stir the oil in the tube by rotating the stick to help it settle down to the crankcase level. Just a theory. I'm going to try the add a 1/4 method. Incidentally, I have made a new dip stick by flattening a 1/8 copper tube and crimping it on a cable, like the original, but I drilled a small hole at the one qt., two qt. and full marks. It helps the reading but the oil level is still questionable.
I wonder if a straight stick with a hinge in the middle would work? Instead of the cable. It could be made from metal or a hinge pin.

[LarryEWaiex121]

Guys,

I feel your pain. I don't have an Aero-Vee and now I don't have a Jabiru. I have a Waiex sitting without its nose, waiting for the Camit to arrive.
The issue is the same(yet different) for all of these engines. The inability to get a quick oil level check in normal conditions.
The Jabiru never had a dipstick designed to go in a 3pt configuration so it leaves one to their own devices.
My Waiex always sits on a sawhorse under the tail to keep the top longeron level, allowing for an accurate reading.
When out and about, I use a piece of aluminum cut off of a section of angle that is both rigid and easily readable.
Speaking to the Jabiru, the sump has an angle at the bottom of the dip tube that stops the flat stick and allows one to read their oil level, "accurately", while in the 3pt condition. I used a die grinder with cutoff wheel to crosshatch the surface and retain oil much like the zip tie trick. Simple, kind of crude, but very practical and completely necessary.
Bottom line, I could check oil and know for certain the level and usage. I sure hope the Camit has addressed this matter?

[DCASonex]

Larry,

Check your oil level in tail down position to see how much it varies from engine level, then ask Ian for a dip stick about by that amount longer, about 10 mm in my case. That will make it a bit too long and end will need to be trimmed to keep it from hitting bottom of side pocket on sump, but still very useful with bottom of calibrated area just about at new cut-off point. (Need to cut off may be different with the new sump casting, I have the old one.) Ian ended up doing this twice, once for original dip stick, then again for new one to fit the inhibitor when that was installed. Inhibitor dip stick cap needed an additional O ring anyway, which is now standard.

CAMit dip sticks are flattened on the end with a series of small holes that retain the oil making it very easy to read.

David A. Sonex TD #1327, CAE 3300 #0004