Replace pistons or keep old ones.

[shanebo]

The 258 block I am working on has about 88,000 miles. I am pondering if i want to keep the old pistons or get new. They look fine and have no sign of cracks or warping...the wrist pins feel very good.....but hey...they still got 88,000 miles more than a set of new ones. I plan on keeping this car for a very long time. Im on a budget but I dont want to cut any corners and have to do this again a few years down the road.

[Smitch]

I dont want to cut any corners and have to do this again a few years down the road.

You may hace answered your own question!!

[rohnk]

If you can spare a little money, I'd go ahead and change them out or put a stroker kit in. Since your down that far anyway, you might as well.

But I'm pretty good at spending other people's money!    Good luck!

[eaglefreek]

If taken care of 88k miles is nothing for a AMC 6. You may not even need to do anything but change the timing gear, oil pump, water pump and gaskets. In my experience, engines from the factory that haven't been opened up and treated well, will typically last way longer than a rebuilt engine. I choose not to rebuild an engine unless absolutely necessary.

[Sunny]

I've seen people reuse pistons without a problem, but if I was going to tear it all apart anyways, I'd at least bore it out, and put larger pistons/rings in it.

Eaglefreek is right though. 88K isin't very much if it was well taken care of.

[shanebo]

It wasnt overly well taken care of...The oil looked like black pudding....the head gasket was shot. I already had the block down to the machine shop It was hot tanked honed and balanced.... Looking at the pistons they look all right but i am sure going to be p***ed off If I get it all back together and in the car and just to have piston problems 6 months down the road.....I think your right about replacing them. If ever there was a time to do it its now.....with the engine down to the block...not such an easy fix once its back in the car....

Thanks for that little nudge to get me going in the right direction.

[Draekon]

I would think that you would be alright with the old pistons if you cleaned them up and installed new rings.  Pistons themselves don't tend to have many issues in street motors compared to the other components in the engine.  Of course new pistons would be a nice insurance measure.

[shanebo]

Anyone know what the going price for new pistons are...and where is a good place to get them? They will be stock size. The only thing done to the cylinder sleeve was a good honeing. The machine shop said stock rings and pistons will fit just fine.....Thanks

I may keep the stock ones depending on the cost of the things.

[carguy87]

You can get complete rebuild kits with rings, pistons, all the gaskets, bearings, and timing set anywhere from $260-$370 depending who you buy from.

[shanebo]

Thats not too bad...Ill have to look around...thats a small price to pay for peace of mind.

[thereverendbill]

summit has them listed from 28 bucks to 208 bucks for the pistons

[shanebo]

Ive found several sets on evil-bay but im always somewhat leary about buying from a stranger across the country...It can go either way...I have been took for a ride before and got stuck with somthing that was completly different than what I needed. Ill have to check out summit.

[Jurjen]

What you can do is is have the pistons and bores measured and when they are well within limit, and only install new rings.
A good indicator is that when you can still see the crosshatch in the cylinder walls.
Another good indicator is lowering the piston in the bore (w/o rings) and support it from the bottom. When you can tip it over from left to right then it is worn too (you can hear this tipping over when the engine is cold: piston slap). It should a tight fit.
Before installing the pistons with the new rings, I use waterproof sandpaper (grid 240) to fresh up the crosshatch; this will make sure that the new rings are properly bedded in.