Great series of photos, and tells a lot.
sludge doesn't usually accumulate where it is formed, sludge in oil solubility drops with temperature...
Look at the bottom end photo in particular...
See the lines next to the bearing exits, where the comparatively higher temperature (from bearing friction) oil flung from the bearing exits has nearly no mess ?
Front main, where the block is comparatively cooler from coolant inlet, and oil fresh from sump ?
Top end, could almost say that the inlet side is more sludged than the exhaust.
sludge doesn't usually accumulate where it is formed, sludge in oil solubility drops with temperature...
Look at the bottom end photo in particular...
See the lines next to the bearing exits, where the comparatively higher temperature (from bearing friction) oil flung from the bearing exits has nearly no mess ?
Front main, where the block is comparatively cooler from coolant inlet, and oil fresh from sump ?
Top end, could almost say that the inlet side is more sludged than the exhaust.