EJ255 rebuild question

[1-3-2-4]

So I need to rebuild this motor and it's been sitting in the truck of my Legacy GT for about 2 months I haven't taken the pistons out but it was close to around 230k I think miles before the rod spun and before that the ringland cracked on one of the pistons..

 

So long story short I'm getting a new crank and bearings but my concern is the piston clearance.. It was not stock and was running a 16G turbo Now I "plan" on doing the pistons myself but leaving it up to the shop to measure but that's where I get confused on how I know which piston sizes to order?

[Fairtax4me]

Depends on the condition of the cylinder walls.

 

If the walls are scored and the block needs to be bored out, order pistons to match the overbore size. If they can just deglaze the cylinders to get the hone back, run standard size.

[1-3-2-4]

Depends on the condition of the cylinder walls.

 

If the walls are scored and the block needs to be bored out, order pistons to match the overbore size. If they can just deglaze the cylinders to get the hone back, run standard size.

Yeah hopefully the walls are in decent shape

[Quidam]

You want to cut any and all wear out of the cylinders. Turbo will blow through any thing less. Hone it and see how it looks. You can get such hones at Auto Zone and such for a deposit, refunded when returned.

 

It's a real challenge to get a block and all the small passages cleaned out If the bearings go like that. Might ruin all your new work if it's not clean.

 

Cracked pistons, scored cylinder walls, bearing pollution, not good. The oil pan is sheet metal pieces welded together, your call but some would just replace it as it's hard to clean as well.

 

You can certainly try though.

 

hth

Edited February 17, 2016 by Quidam

[Rooster2]

With 230K miles on the motor, possible or probable cracked pistons, scored cylinder walls, and good chance motor shavings went everywhere to plug passages, I think I would throw in the towel on the engine, and go with a different motor. Just my 2 cents worth.

[1-3-2-4]

So I was messing with the motor while in the trunk and it's for sure the rod bearing for piston 3 that's no good.. when at TDC if you push the piston it has a little play..

 

Now as far as scuff.. seeing as it had 23 PSI going to it about midway travel is some wall marks but it's for all them.. I took a video of it