Saving Old Seagulls

I don’t have these supply lines, so I’ll stick with my last reply! But presumably that means the later boxes (such as my present 10:21 featherweight) are happy on a slightly heavier oil than sae 140, although I imagine the engine gets to the point where it develops less power at the prop because it has to deal with the heavier oil

What did you think of the pulse oximeter point?!
Donald

I wonder if you'd get false positives from smokers, asthmatics, ex-miners & at what point in the drama does lung impairment become measurable.

That's an interesting thought, which box has the most drag, (2 oil seals, SAE 80) (no seals, SAE 140) or (worn bearings, worn shafts, thickened lube)?

It would be more difficult to measure the extra drag from the V seal when under load as you'd have to put 40lbs push on the prop shaft.

Thank you for that - all very good points, to which I definitely do not have the answers, and which I have to resist the temptation to chase them with speculation.....!!
Till the next time
Donald