RV-8 dipstick calibration question

I'm just about to calibrate my dipstick (Superior IO-360; stock oil cooler placement). I'm wondering about whether or not the oil cooler should be pre-oiled. It looks to me that it wouldn't hold the oil; it would just drain into the case anyway. Also wondering about whether the engine pre-oiling is typically done with the oil cooler starting out empty. Suggestions welcome.

I just calibrated my dipstick on a 390. My procedure was as follows.
Put 4 quarts in and lets it sit a couple hours. Confirmed the mark on the dipstick.
Then added quart 5 & 6 one at a time and noted levels.
I did not worry about the oil filter or oil cooler volumes. My reasoning was the dipstick is designed to measure the oil level in the sump & in my setup the oil filter and cooler is always full of oil when regularly flying. ( Besides there is really no accurate way to calculate the volume of cooler and filter)

What I did find on the 390 in a RV-14 taildragger is that the dipstick hash marks were not accurate. I attributed this to the engine not being level being in the 3 point position. I did find that the distance between the different hash marks were correct indicating the difference between quarts.

In the end oil level is really not that critical. Lycoming gives a wide range of operation.

My intent is to fly between 4- 6 quarts. My main purpose in the calibration was to accurately determine a 1 quart increment to determine oil consumption rates.

I would run the engine, perform an oil change, and calibrate it while you are refilling it. I would think you want the calibration while the plane is sitting 3 point just as you would as you’re preflighting it.

Oil Dipstick

I just got my engine running again after overhaul by Aerosport and basically did the same thing as Glenn. My dipstick had no markings so I put in 4 quarts and let it sit for a couple hours, then 5, 6 and 7 the same way. I numbered each of those on the dipstick with a tool my A&P buddy had. My engine just spits out anything more than about 6.5 qts anyway so that’s all the markings I needed. I didn’t worry about filling the cooler or the filter since the dipstick is measuring what’s in the sump.

That's what I did. I wanted to add at 5. I changed oil and filter, added five quarts and started engine to check for leaks and such. Came back the next morning and checked the level on the stick and marked it, then added another quart and marked that.