I was thinking if the bearing is worn egg-shaped, the plastigage even if torqued down carefully without movement might not detect the max wear if it wasn't oriented right. So if it was predictable where the wear would be, then I was thinking the crankshaft orientation and position of plastigage on it could be determined. However, I'm not sure what forces were more likely to have caused bearing wear - IE: high centrifugal force from the overrev (peaking at TDC between exhaust and intake stroke; pulling "up" on the piston/rod), or damage caused by the piston valve interference would be approaching TDC but would be in a downward direction on the piston/rod.
I am recalling now sometimes after driving the car very hard, seeing alarmingly low oil pressure at hot idle, IE: lower than normal even.
May I recommend an oil temperature gauge? I generally put one on anything that's driven hard. It tells you SO much more than a water temp gauge can.Marcel
I've heard good things about leak down tests.
Regarding wet compression test - no bentley does not state you can't do it. In fact, it explicitely states you can. According to my bentley (covering '77-'84 Rabbit / Jetta Diesel) it states: "To determine whether the piston rings are causing low compression squirt a small quantity of SAE 40 oil into the low-reading cylinder(s) through the injector hole(s), and repeat the compression test. ..."
Mark the Miser - on a leakdown test, to rule out the rings, engine oil is added. But unlike the compression test, the pistons are not moving up and down, it's just the rate of air leakage that is being measured, so the oil would definitely stay down around the rings where gravity would make it go. It would only help seal the rings. It would not get splashed around inside the combustion chamber by moving pistons and could not possibly help seal valves. It would indeed be more definitive test than a "wet compression" test.
I am thinking that based on my compression test, I've got some problem that's definitely not starter, electric, or fuel injection related.
Common sense says if the machinist screwed up the valve job, it wouldn't be exactly even on all cylinders. But at the same time, it is possible...