Quote:
Originally Posted by ROLLGUY
Believe it or not, you may be correct. After pondering the situation, I went out into the garage and decided to completely remove both bearing halves and tighten up the rest of the caps. You guessed it, the crank spins freely. I only used one half of the bearing (harvested from an engine yesterday), but then used BOTH halves from the parts engine in my garage. Evidently the bearings I got yesterday were in fact undersized. Lesson learned: use the entire assembly, not just part!
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The real lesson is to read the back of the bearings and use plasti gauge every time.
Quote:
Originally Posted by ROLLGUY
Here is the other problem I am having with this engine. After sorting out the main problem, I plastiguaged all 5 rods, and they all are well within spec. The oil clearance is something like .39 to .79, and they all are around .51. I can't imagine what would have caused the rod knock with the new bearings. I showed one (the worst) to my engine guy, and he said they are fine. Is it possible that there could have been some bearing material on the crank the first time that would cause a knock? If so, it would have been polished off. I don't want to put the engine back together and find out the knock is still there. The car is a low mileage coupe with perfect body and interior. It would be a shame to put an engine back in with a knock.
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Built up bearing material won't cause excessive clearance ( bearing knock )
You have other issues like a wrist pin or broken piston skirt.
You can check for loose pins by turning the engine so the piston is on it's way up, stop then push the piston from the bottom. If you feel any movement, the wrist pin bushing / pin is bad.