Originally Posted by
BroomstickPilot
Well that's my view anyway.
You're entitled to your view - just don't try joining any Yak syndicates though - if you want to destroy an Ivchenko, make sure you own the whole thing and not just a share of it!
You're correct in that if you do have a significant hydraulic lock, the resistance to pulling the prop through increases to the point that you can inflict damage on the engine if you insist on trying to force it round - at which point it is certainly time to pull some plugs (and if you don't pull it through, you won't know about it).
Leaving even small amounts of oil pooling in the lower cylinders can lead to small hydraulic effects which have been blamed for the propensity of the Russian spark plugs - invariably in the lower cylinders - to blow out the ceramic cores. The cylinder may well continue to fire after a fashion on the other plug, and make a god awful noise in the process - as well as leaving the shattered end of an HT lead in the engine compartment, and if you're really unlucky, the gasses escaping via the blown-out plug can be drawn back in and choke the engine - at least one example has ended up in a field that way.
Your engine need not be be worn for oil to start pooling in the lower cylinders - it might just have been designed that way.