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oil dipstick calibration

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prkaye

Well Known Member
My oil dipstick came with no markings on it. I was told by Aerosport that this is the way they come - they are supposed to be manually calibrated by adding oil 2 quarts at a time and marking the dipstick each time.
Unfortunately I've already added full oil to the engine, so I'll have to wait for my first oil change to do the lower markings.
Question - how on earth do I mark the dipstick? On production airplanes I've seen the dipsticks with the tiny markings engraved on the stick... I don't have the equipment to do that sort of engraving...
 
Just use a file for the marks. If you have a dental lab near you they could engrave the numbers with a bur. Don
 
Marking Dip Stick

I used my tubing cutter to mark 4, 6, and 8 qt lines.
I just very lightly scored the stick. Simple and Low Cost
 
In a 4 cyl lyc you only need 4 marks (2,4,6 & 8). Pretty easy even without numbers, but if anyone knows how to mark a nice numeral on a round stick without whacking the **** out of your stamp, let me know. I've tried engravers, but I can't do it. I Just scrawl.
 
I filed a flat into the rod at each level and then stamped the number in the flat. Works well because the oil hangs in the flat and new oil is hard to see.

However...I didn't factor in the oil that is trapped in the filter when I did the fill-and-mark routine, so my marks are all a bit high.
 
Oil in filter included?

Does the number on the stick include any oil that might be trapped elsewhere in the system (like in the filter, etc)? I'd assume it does.... (?) Or should it only indicate what's actually in the sump?

This dipstick needs to know, since its time to mark mine.
 
Bill Wightman said:
Does the number on the stick include any oil that might be trapped elsewhere in the system (like in the filter, etc)? I'd assume it does.... (?) Or should it only indicate what's actually in the sump?

This dipstick needs to know, since its time to mark mine.
Click to expand...

It should indicate all. Why not mark the stick at your first oil change. Start off with the required amount of oil....... 7 or 8 quarts. Mark the stick with a sharpie at the top level so you can check consumption during your first few hours.

At your first oil change, add only 4 quarts and a new filter. This is your lower limit. Now run the motor for a few minutes so everything gets full of oil. Shut it off and let it set a few hours. Make your first mark. Add the next quart or two and mark for that etc, etc, etc.

I used HF 1/8" stamps for the number and the line. To stamp the round rod, hold it in a vise with the rod extending over the top of the bench and have it rest on a bucking bar or other solid surface, Start with the punch centered on the stick..... tap easy with the hammer as you lean the punch around the rod. Try it on some scrap first......................:)
 
OK so maybe to bracket both ends of the range, I could put in 4 quarts then run the engine a minute or two. Shut down, allow sufficient drain-back time, and note the level on the stick. Then add another 4 quarts and note that level.

That would properly show the 4 and 8 quart levels, with the correct amount of oil trapped. Sound good?
 
fl-mike said:
I filed a flat into the rod at each level and then stamped the number in the flat. Works well because the oil hangs in the flat and new oil is hard to see.
Click to expand...

This is the best idea I've read all week. I am so stealing it. :)

mcb
 
I believe the procedure with my TMX-0360 was to mark the dip stick as you added the oil for the first time. Check with your engine manufacture to see what they recomend.
 
I marked for the oil in the pan which I believe is the oil the engine companies count as a filter is not standard on the engine. This way the oil in the pan is what is used to lube the engine and the extra is in the filter.
I put 7 qt in at oil/filter change. I run the engine and it is a bit over 6 qts. If it is any higher then 6 qts on the stick (in the pan), the amount above 6 gts is usually on the belly of my plane after a 1 hour flight because it is expelled through the breather.
 
how much oil?

Reviving an old thread, since I'm going to need to mark my dipstick "soon".

One question is what constitutes the "right" amount of oil? Not just "6 quarts", since I guess the engine does not care, but there seem to be several factors to consider:
  • oil pickups in the engine that should be covered by a certain volume of oil;
  • having too much will cause a lot of resistance;
  • need to anticipate the oil burn rate so you don't run out of oil on a long cross country;
  • etc.
Apologies if this analysis has been done, and I have not yet found it.

My current plan is to drain everything, put it in a couple of quarts at a time, mark the stick, and then later, after break-in, determine the "right" amount of oil for my engine based on the burn rate at different volumes, down to the "minimum".
 
The stick is measuring oil level in the pan, not oil that is elsewhere.

A couple of extreme thought examples.
If I had a six quart filter full of oil and an empty sump, what would you want the stick to read?

Or a further stretch,

I have 2 quarets in the sump and 4 quarts in the baggage compartment, what should the stick read?
 
The factory marks are stamped so as not to create a stress riser. Filing and cutting with a tube cutter will create stress risers on an engine part that surely vibrates as it is supported on one end only
Put in six quarts, note where it reads and that is where you want to be. Done
 
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