2 ring piston ?

[premix]

Do any of the newer Husqvarnas models use a 2 ring piston? Or are they all 1 ring piston.

 

[Lawn Masters]

I think it depends on the model. I like a 2 ring, but 1 will do the job as well. The number of rings doesnt have much to do with compression, I think it was for better heat transfer from the piston to cylinder walls.

 

[TonyM]

I'm sure the 362xp, 365, 372xp have two rings. Not sure about others.

 

[SawTroll]

I have seen several posts on this, going through the arcives. Have you tried the search function?

 

[premix]

I have seen several posts on this, going through the arcives. Have you tried the search function?

Thanks for the replies. I have tried the search but have got mixed results. I'm interested in a 372 but would like to know if the later ones are a 2 ring piston. It almost sounds like earlier 372 used 1 ring piston a later 372s used 2 ring pistons from my search results. I was wondering if someone had a parts book that might tell me something on the 372.

 

[shalenkur]

any good saw will have two piston rings. if a saw has only one ring I wouldn't buy it.

A saw with one ring is not a heavy-duty saw.

I can't see husky selling one ring saws except in their consumer line, but who knows these days . . .

 

[brent denny]

That is simply not true. Some of the best saws ever made used one piston ring. Jonsered 670, dolmar 7900 etc. I believe the 365 and larger have 2 piston rings. Yes some of the original 371s and 372s had one ring but any one that you get new now will have two.

 

[ehp]

most 372's that were meant for Canada have 1 ring the saws with 2 rings were EPA standard saws. to me it doesnot matter if it has 1 or 2 rings they both work and you will find 2 rings on the bigger bore saws

 

[Mange]

None of the Husky's here has 2, just the EPA and them we export.

 

[shalenkur]

I stand corrected.
It's just that from what I've seen all the commercial-grade 2-cycle equipment I've had experience with has had 2 rings and all the "occasional-use" type equipment I've had apart was one ring. but I'm relatively new to chainsaws, sorry for the mis-information.

Though I'm still partial to dual rings.

 

[rahtreelimbs]

This has been argued before. The Dolmar 7900 has one ring. That didn't stop me from buying it.


The 2 ring is better than 1 ring is moot IMO!!!

 

[Mange]

I stand corrected.
It's just that from what I've seen all the commercial-grade 2-cycle equipment I've had experience with has had 2 rings and all the "occasional-use" type equipment I've had apart was one ring. but I'm relatively new to chainsaws, sorry for the mis-information.

Though I'm still partial to dual rings.

This is no biggie

There is a lot of experimental Huskys with two rings as well, i have a 444sg with that piston with the rings that are so thin you could brake them just by looking a little too hard.
Many "Harry Homeowner" has 2. I have a few macs here fore ex.
I do not think it has anything to do with pro or not as a standard. i think it is personal preference.

 

[Justin Garrison]

I have a stihl 031 that has 2 I thought that was kind of strange for a 30 year old saw,but whatever.

 

[Mange]

I think the 1 ring feature is a Husky idéa, the Stihl's i know of has 2.
Generally speaking.

 

[Crofter]

It could seem that more and wider rings would be an advantage for sealing and wear, but there are other things that may be the limiting factor at high rpms. The rings main sealing power comes from pressure from the gasses above it rather than ring tension. This also has a controlling effect on ring flutter. Decelleration forces are greater on heavier rings and lower rings are in the pressure shadow of any upper rings. Lots of little tradeoffs the engineers have to consider in their design. If the one system were clearly better all around than the other, the one using the inferior would soon be at a reputation disadvange they couldn't afford. That doesn't seem to be happening.

 

[bwalker]

Consider this. Almost every two cycle made today has dual rings with only a few exceptions. The only advantage a single ring has is it gives slightly less drag than a dual ring setup(barely measurable if at all). I dont know how many of you have snowmobiles, but Ski Doo uses single rings pistons on some of their models and they have major issues with them. Many guys replace them with dual rings before they even drive them. Another thing to consider is Wiseco offers a single ring piston for certain dirt bikes. The single ring pistons they sell have a lower servive interval than the dual rings they sell. I have no doubt that dual ring pistons are superior in almost every regard. With that said I think that a single ring piston is acceptable in a saw because of the bore size.
BTW maybe Husky uses single rings on certain saws sold to particular markets to save $?
http://www.2strokeheads.com/Ski_Doo_Rotax_800_Twin_Piston_and_Head_Kit_by_RK_Tek.html

 

[DanMan1]

Here is a pic showing the single ring piston on my new 357xp

 

[canguy21]

The two ring guys make a big deal out how their rigs are much better quality and long lasting. Husky claims less heat due to lower friction and quicker acceleration with a single ring. I have also been told by a Husky rep two ring is old technology and and a good single ring setup seals just as well. Take your pick.

 

[bwalker]

I think your Husky rep is a moron. A dual ring piston will always run at lower temps than a single ringer as the rings are the primary means of heat evacutaion.

 

[spacemule]

Has anyone experimented with ringless pistons on saws? At least on model airplane engines, the ringless piston setup is more expensive and makes more power. The downside is greater sensitivity to dirt ingestion, as it screws the cylinder/piston fit up.