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EJ257 Crank walk? Possible to save the crank/piston/rod combo?

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Hey guys.

So in summary trying to diagnose the possible issue of crank walk.

A little bit of info about the engine in question - The engine is an ej257 from an 08 USDM STi, the pistons are Cossworth, the rods are Carrilo super A beams, and the crank is some sort of aftermarket billet crank from the looks of it (I will teardown the rest of the short block later on today). The engine also came with an ACT 6 puck metal clutch and ACT flywheel that had significant damage - Visible heat spots and major valleying radially on the mating surface of the flywheel and pressure plate. Otherwise, the motor had great compression numbers (155-150 psi across all 4 cylinders)

I mounted and zeroed out a dial bore gauge on the front of the crankshaft and it measured out 8.5-9 thou of play. I know this isn't Subaru's procedure on how to measure thrust clearance but I just wanted to show how bad the situation is.

My major question (especially to people with experience with this issue on this platform) is what are the odds that only the #5 rear main/thrust bearing took a dump from the previous owner's abuse coupled with a heavy clutch kit? And what are the chances I could salvage the internals for another good donor block?

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It's going to depend on the strip-down, but rods and pistons should be fine.

With the crankshaft it's going to depend on the major thrust face - it should be possible to clean it up and polish both thrust faces to give a clean, true running surface. This means the distance between the thrust faces is going to be too big, but you can buy custom rear mains/thrust inserts (can't recall which the engine uses) that are thicker to compensate for that and give the correct end play. No specific recommendations, but any of the companies manufacturing EJ bearing should be able to sort you out for a reasonable fee.

When re-assembling for the dummy build, there are a couple of tricks that may be applicable to aid the oil feed to that thrust surface - the easiest is to file a SMALL chamfer on the ends of the bearing shell to the centre grove in the upper shell, which will divert high pressure oil to the thrust face as it sweeps by, and some have drilled a SMALL (1mm) hole through the face of the thrust bearing into the oilway that feeds the rear main (or whichever it's on), to directly oil the interface. Don't know if they're applicable, but might help.

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