2.3L ('83-'97) 91 2.3 I pulled from a junkyard, hows the piston walls?

[MaD]

I pulled this engine from the junkyard to open it up and learn a bit about how to rebuild a 2.3 how does the piston walls look? I'll upload more pictures later. Cleaned up the pistons a bit, one of em has little holes in it.

 

[scotts90ranger]

Well, not sure on the cylinder walls, can't see crosshatching but that engine has been rebuilt before and has .020" oversize pistons installed... the cylinder walls look straight though so I wouldn't be afraid of running them but a hone and new rings wouldn't be a bad idea while you're there...

 

[pentode]

Where are these holes in the piston?

Maybe do the old fingernail test on some of the worst scratches. If there's nothing major and you don't want to do full machine shop treatment, dingleball hone and rings as scotts90ranger said and you'll probably be fine. Holes in pistons, not so much (unless they're oil return holes)

Edit: I can't see any crosshatch either, but since it's been rebuilt it's hard to know what the previous machine shop did - some places are more perfectionist than others.

Looks like you're just using it as a learning experience though so if it's just academic, ignore everything I said other than I'm still curious where those holes are.

 

[MaD]

Where are these holes in the piston?

Maybe do the old fingernail test on some of the worst scratches. If there's nothing major and you don't want to do full machine shop treatment, dingleball hone and rings as scotts90ranger said and you'll probably be fine. Holes in pistons, not so much (unless they're oil return holes)

Edit: I can't see any crosshatch either, but since it's been rebuilt it's hard to know what the previous machine shop did - some places are more perfectionist than others.

Looks like you're just using it as a learning experience though so if it's just academic, ignore everything I said other than I'm still curious where those holes are.

 

[MaD]

I'll upload better pictures

 

[MaD]

Well, not sure on the cylinder walls, can't see crosshatching but that engine has been rebuilt before and has .020" oversize pistons installed... the cylinder walls look straight though so I wouldn't be afraid of running them but a hone and new rings wouldn't be a bad idea while you're there...

Is

Well, not sure on the cylinder walls, can't see crosshatching but that engine has been rebuilt before and has .020" oversize pistons installed... the cylinder walls look straight though so I wouldn't be afraid of running them but a hone and new rings wouldn't be a bad idea while you're there...

Is that a good thing or bad thing .020 oversized piston?

 

[alwaysFlOoReD]

Those are not holes. Those are divots. Holes would go thru to the other side.

 

[alwaysFlOoReD]

Is

Is that a good thing or bad thing .020 oversized piston?

It means that it has been rebuilt before. Not good or bad, just less rebuilds available in the future. Depends on wall thickness and oversize piston availability.

 

[pentode]

Those are not holes. Those are divots. Holes would go thru to the other side.

+1 had some junk run through that cylinder.

 

[pentode]

Is

Is that a good thing or bad thing .020 oversized piston?

It means that it has been rebuilt before. Not good or bad, just less rebuilds available in the future. Depends on wall thickness and oversize piston availability.

I don't know for certain but I'd be surprised if you could go much bigger than .030 on that engine so the next overbore might be your last as alwaysFlOoReD mentioned.

 

[scotts90ranger]

New rings and a ball hone do wonders on engines, unless there's big scores in the cylinder walls I wouldn't be worried at all... the engine in my '90 has pretty good ridges at the top of the cylinders that I just left there like 8 years ago when I built it, honed it and have just been running it, a lot of people are persnickety, janky stuff works fine .

if you want to play with it and get the full experience I would pull the pistons and do all the things, get a cheap hone (ball or stone, whatever, the walls look straight, if you don't have anything I wouldn't spend a lot unless you want to do more, I got my ball hone free from work since they were replacing it...) and new rings (they sell them by bore size, since you have .020 pistons get those. Once you get the rings and get ready to put it together put the rings in the cylinders they'll go in and push them about 1" down the cylinders and check the gap which should be 0.003" per 1" bore if I remember right and adjust as necessary (google is your friend on sizing rings). Aside from that new bearings and you should be good to go...

 

[SenorNoob]

That piston looks like something small and hard (metallic or maybe carbon build up) bounced around in there a few strokes. Or someone gouged it while cleaning carbon build up off to get the pictures...

Theoretically that would cause hot spots on the piston surface. In reality before it became a problem you'd have already melted something else... LOL

This is the engine currently in my truck: (I know 4.0, but the principle is the same.)

I took off a serious ridge of carbon at the top of the cylinders with a red Scotch-Brite pad soaked in penetrating oil. That was the only work done in the bottom end. I've been daily driving it for almost exactly a year now. Engines are WAY more forgiving than the books would have you believe.