Jowe, the OEL cap is not only a valid fill point, it's really easy and clean to use with a syringe.
Paladin, I followed your suggestions to the letter, using a 10 ml syringe for accuracy and a black plastic tie-wrap (notched on the shiny side) for visibility. You were kind when describing the difficulty of using the bronze pin dipstick. I would call it useless as a dipstick. I was finally able to read it after laying it full mark down on a paper towel and rolling it 1/2 turn to visually compare the full mark with the end of the oil stain on the white paper towel.
The tie-wrap duplicates the function of the dipstick perfectly, total length and full mark location from the tie-wrap "ratchet", designed so that the ratchet part fits into the hole and always stops in the exact correct place. See the first photo.
After filling to 100 ml, the dipstick (tie-wrap) had 3 mm of oil on the tip which was 12.5 mm from the full mark. See the second photo.
After filling to 150 ml, the dipstick had 10.5 mm of oil on the tip which was 5 mm from the full mark. See the third photo.
After filling to 170 ml, the dipstick had 15.5 mm of oil on the tip which was exactly at the full mark. See the fourth photo.
Conclusions:
1) Since the 50 ml volume change from the first to second
measurement changed the level by 7.5 mm (1.5 mm per 10 ml of
fluid), and the 20 ml volume change from the second to third
measurement changed the level by 5 mm (2.5 mm per 10 ml of
fluid), the conclusion is that the level change vs volume change is far
from linear. Surprise, surprise! The geometry of the inside of the
injection pump is very complex.
2) Since the total oil introduced to this clean and dry injection pump
was only 170 ml to reach the dipstick "Full Mark", and many posters
indicate that the pump requires from 200 to 250 ml, I conclude that
there are volumes in the pump that are still currently dry and will
receive and trap oil from the reservoir once it is run and that, like
the engine, it must be topped off after it has been primed or at least
after it has been started and run for the first time after a rebuild.
After priming the engine and injection pump, I'll let them rest a while then I'll recheck the level in the pump and measure the amount to be added to get back to the full mark, if any. Then I'll come back here to post the results.
You may have to scroll to the right to see the tie-wrap dipstick in the first photo.
I don't know why.
Tom Kizer
Levis, Quebec, Canada