1 or 2 piston rings?

[stihl only]

I asked the same question a while back and the replies boiled down to:
1 ring – tighter tolerances,
2 rings – looser tolerances, thus two rings to stabilize the piston,

and I forget which one was more efficient at heat transfer.

Well the skirt is what makes the piston stable and with the rings right next to each other, an extra one wouldn't make it a bit more stable.

I'm not a book learned engineer but in my mind, two rings=twice the surface area to transfer heat.

 

[stihl86]

Does that mean a two ring design is 50% more efficient at transferring heat?

 

[Lakeside53]

You need to factor in the thickness of the rings... most single rings are 1.5, 2 ring 1.2, and the thermal resistance of the contact area (whch is 2x in two ring designs). Bigger blowers (stihl) tend to have 2 1.5 rings - and long life; they run at max HP for entire tanks which is why they are "beefier" in design.

 

[04ultra]

Just like most other things,.........just keep getting made cheaper .

Like most Huskys .....1 ring....