If theres something so wrong with bearings that one is smoking, oil isnt getting to that bearing - either oil level or flow blockage. Was the original reason for replacing pistons and cylinders a sudden appearance of bits of metal / piston in the oil ? The engine will probably feel stiff with the spark plugs out if a bearing is failing. It was interesting at Techenders a while back there was a reasonably freshly professionally rebuilt T4 engine with oil temperatures climbing up to motorway temperature while idling..
