Hello,

I have a newly built (sleeved, rods, pistons) turbo B18C1 (only 6psi boost) in my EJ8 civic, the motor recently developed a piston slap and I've just finished pulling and stripping the motor apart after finding metal in the oil filter.

Piston #1 has some severe scoring on one of its skirts and left some damage on the bore. All crank mating/bearing surfaces look to be in good shape. The main bearings have some discolorations from heat. All the other pistons look to be in good shape and all rods look fine as well.


The motor has overheated once (temp gauge in the red) and it lost a significant amount of oil once, after the turbo oil return fell off (never saw a drop in oil pressure from my gauge).

The knocking noise happened after a spirited drive but the temperature gauge never budged from halfway and oil pressure was normal.

What do you think the cause is and how should I proceed with rebuilding?

 

Take to someone who actually knows what they are doing to build a engine. Your piston to wall clearance was obviously wrong. Next step would be inspect all the bearing journals (cams and crank) for scoring, then bore the cylinders to the almost .5mm bigger, get some bigger pistons and then hone the block to the proper piston to wall clearance. Due to the metal that was introduced to the motors internals and lack of oil, you may have some serious issues. Everything needs to be torn apart and carefully checked over including the oil pump! Have the crank inspected at a shop when you go to get the block taken care of.

 

Any pics of the other pistons/bores, or the bearings? Hard to tell just on the picture but based on the damage on the piston skirt and what I can see on the cylinder, looks like you're going to have to bore out the wall and get a larger set of pistons... Also unsure if the builder is to blame or not since you had the overheating and oil loss issues, and the other pistons/bores look fine.

Agreed with MaxCapacity that you'll need to disassemble the full engine and clean out all the oil galleys. Replace the pump as recommended. Sorry man, good luck.

 

All machine work was done by Active Engines in Toronto. Would have hoped they got the piston to wall clearance correct but I should have double checked myself it seems.. All the other bores appear fine but have some slight scuffing/wear (no where near as bad as this #1 cylinder).

Motor has been fully torn apart now, I have attached images of the other cylinder bores. #s 2,3 and 4 are showing some scuffing (can't get my fingernail to catch on these, images attached) and the main bearings showed some discolorations and a metal fragment was found on a main bearing.

All journal surfaces seem to be in good shape, but I am not a professional and will bring it to someone who is.

Can the oil pump be cleaned/reused?








Attached are images of the other bores.

 

I didn't mean to sound harsh in my last comment.. just unfortunate as to what happened.
Looks bad but I've seen worse. I'm rebuilding a friend's sleeved block aswell that has worse damage than yours due to same problem but his didn't over heat and lose a oil line. The shop he took it to messed up twice on his block so I have it now.
Your oil pump can be re-used if the pump gear inside looks and feels fine (with no metal particles embedded into it or any scoring) after opening it up.
That really sucks though, after all you put in it and now this. Hope after its fixed up you actually get to enjoy it to its full potential and get some years out of it.