New piston old rings?

[Brent Nowell]

would you guys consider this?
Say if you just broke in a set of rings over the last year and compression is great and you get a new pop up piston would it be wise to use the old rings and not the new?

Or is this blasphemy in the engine world?

I suppose for this to actually work properly the piston ring pins would have to be in the exact same place as the old piston?

 

[dmb2613]

it will be fine , what's a set of rings cost 10 bucks

 

[cus_deluxe]

i wouldnt worry. its a chainsaw, not the space shuttle haha.

 

[Huskybill]

Caber rings are cheap if you shop around. I’d install new rings, break it in. Put the compression readings in a log book and I would check it every six months if the saw is used a lot or once a year if it’s not used that much. Once the compression starts to drop you know to replace the rings. I’m sure we all would love to hear the results of its longivitey.

I do things once and do it right. If it fails then we know it wasn’t the new rings.

I did the same with dirtbikes if it failed many hills and valleys away from the truck it’s a long hard push. I never broke down thank god. We ran the gas pipeline in mass. You can ride farther than we could see. Many many miles. Your bike better run right.

Just like when my saw is sharp and gassed up when I have the tree knotched and I start the back cut it better not fail.

 

[s sidewall]

Just install a new piston, rings are already seated to the bore. Just install them in the same location.

Steve Sidwell

 

[Huskybill]

Save the old piston and rings as backup?

 

[jltrent]

I don't even use the same hog rings over and I darn sure would not use worn piston rings on a new piston. Kinda defeats the purpose.

 

[rupedoggy]

Got some picky hogs there.

 

[Brent Nowell]

Well it has nothing to do with the money and everything to do with the superior compression the old rings have. Sidwell thx!

 

[huskihl]

Well it has nothing to do with the money and everything to do with the superior compression the old rings have. Sidwell thx!

I'd compare pin locations. If that checks out, and they're good fresh broken in rings, and the same thickness (1.5mm vs 1.2), it won't hurt anything.

 

[s sidewall]

If I just got a new set of rings seated and broke in, I'm not gonna want to start over again, especially if they aren't worn out. What's wrong with the piston by the way?

Steve Sidwell

 

[cuinrearview]

HL had Cabers on sale for about half price last week.

 

[jltrent]

If I just got a new set of rings seated and broke in, I'm not gonna want to start over again, especially if they aren't worn out. What's wrong with the piston by the way?

Steve Sidwell

I was going to ask the same question......IF you have good compression after already testing the old rings in the saw on the new piston then why the original question. If they were the right rings they sure would not hurt anything. FOr around $10 if I am going to buy a new piston I want good rings to install while I have it torn down as usually that will make better compression after a few tanks. Glad it worked out for you as a saw will run on 120 psi, but usually new ring and some run time will increase that and maybe by much as 30psi depending on the cylinder condition.

 

[Huskvarna hotellgäst]

Well it has nothing to do with the money and everything to do with the superior compression the old rings have.

An unusual dilemma. As I understand it, you're replacing a perfectly good piston with nicely bedded-in rings.
The cylinder wall is hardest, then the iron rings, then the alloy piston.
It's not as simple as this but the cylinder wears away the the rings outer surface and the rings wear away the ring lands, so in theory, you could successfully re-use the rings....(I'm not completely sure I've been helpful )

 

[Yotaismygame]

Doesn't take long to break in new rings....

If the ring sits in the same spot I don't see why it matters. But would I do it... no

 

[grizz55chev]

If I just got a new set of rings seated and broke in, I'm not gonna want to start over again, especially if they aren't worn out. What's wrong with the piston by the way?

Steve Sidwell

He’s installing a pop up, I’d go with new in this case.

 

[Brent Nowell]

An unusual dilemma. As I understand it, you're replacing a perfectly good piston with nicely bedded-in rings.
The cylinder wall is hardest, then the iron rings, then the alloy piston.
It's not as simple as this but the cylinder wears away the the rings outer surface and the rings wear away the ring lands, so in theory, you could successfully re-use the rings....(I'm not completely sure I've been helpful )

Yes you have, thank you.

Yes i am installing a pop up, there’s a thread in the modded work saw forum.
Gonna use the rings that came with the piston, as another said it’s not long for break in, I’m over complicating things lol. Thanks for all the responses

 

[old guy]

Doesn't take long to break in new rings....

If the ring sits in the same spot I don't see why it matters. But would I do it... no

It took 13 tanks to break in my 572, that was using Shaefers 9000.

 

[Yotaismygame]

I see peak comp numbers after one or two tanks.

 

[drf255]

If the ring pins aren’t 100% on the money, you wont see the benefit of keeping the old rings.

If the popup is AM, It’s likely they are a bit off.

Personally, I’d add a new top caber and retain the old lower ring. Better upper ring tension and the benefit of a looser/less drag lower ring with the same heat dispersion.