One ring vs two

[Jughead]

Husky does it.BUT on some single ring huskys i see a lot of blow by on the pistons.blow by = compression blowing oil film lower on the piston during the up (compression) stroke.
Then again we have thin ring pistons where both rings doesn't even equal the thickness of one single thick ring.
Then not all single rings are thicker for example husky puts a 1.5mm ring in the 357xp the same ring fits the stihl 028 super.etc.etc.etc.
I have been thinking of running a single ring in my next 026 build for my buddy steve just for experimentation purposes.i can get side by side comparisons with a double ring in the other i'm building.if it bites the dust? I'll just rering it with two.
As far as assembly vs single or double.i prefer assembling a single ring saw.that second one to me is a pain in the ass to stuff in.

 

[Mark71gtx]

I like two rings. It is like an insurance policy. One if them is bound to hold compression, lol...

 

[Moparmyway]

Instead of just stuffing yer pie eating hole, hows about weighing in (carefully) about any experience(s) you might have relating to the residual oil in the bottom end when comparing one ring verses two ?

 

[Mastermind]

Thoughts on the discussion?

 

[Keith Gandy]

When I do a 51.4mm XPW top end, I leave out the lower ring.

It's too close to the transfer port to allow any widening at all. Those ports need to be widened just to be as large as the 50mm jug.

I noticed that the other day when John got a xpw in the shop and we noticed the skirt edge was even with the transfer edge. I told John u couldnt widen the transfer any at all

 

[jmssaws]

I think residual oil can be directly linked to how the saw was ran before inspection, I doubt that it has much to do with how many rings are on a piston but I'm gassing up two 230lb 066's now,one with both rings and one with a single.

Gonna make some hard cuts with a 36" and check cylinder temps.

 

[bwalker]

Without mentioning any names of who built something .............

1. Is there an advantage of removing the bottom or top ring ?
2. What gains would I expect to see if I removed one of the two rings ?
3. Is there any truth to the "rumor" that removing the lower ring results in a dry bottom end ?
4. What losses should I expect to have with the lower ring removed ?

I believe point 3 to be completely false.

 

[Moparmyway]

I think residual oil can be directly linked to how the saw was ran before inspection, I doubt that it has much to do with how many rings are on a piston but I'm gassing up two 230lb 066's now,one with both rings and one with a single.

Gonna make some hard cuts with a 36" and check cylinder temps.

Will you be able to peek into the lowers of both to compare residual oil ?
Keeping in mind that both saws would need to be operated the exact same way ?

 

[Redbull661]

Instead of just stuffing yer pie eating hole, hows about weighing in (carefully) about any experience(s) you might have relating to the residual oil in the bottom end when comparing one ring verses two ?

busy shoveling and drinking! Beer is great when you shovel snow. Keeps you warm and stuff.


stihl model ms 661 with the bottom ring removed. Running 32:1.

piston top - dry black powder
exhaust port - dry
piston skirts - dry
crank shaft etc - dry
muffler - dry
Piston skirts - look a little beat up.

Right now I am only running the 661's. I know the oil I'm using and I've never seen things look like this with this oil at 32:1. Why this is happening. I don't know.

Same saw, same 32:1 oil, bottom ring back in

piston top - very slightly moist
exhuast port - very wet
piston skirt - very wet
crank shaft etc - very wet
muffler - moist

 

[mdavlee]

I don't widen the intake side transfer on the xpw. The ring placement sucks but in a work saw I leave it.

 

[Moparmyway]

busy shoveling and drinking! Beer is great when you shovel snow. Keeps you warm and stuff.


stihl model ms 661 with the bottom ring removed. Running 32:1.

piston top - dry black powder
exhaust port - dry
piston skirts - dry
crank shaft etc - dry
muffler - dry
Piston skirts - look a little beat up.

Same saw, same 32:1 oil, bottom ring back in

piston top - very slightly moist
exhuast port - very wet
piston skirt - very wet
crank shaft etc - very wet
muffler - moist

Were the two seperate runs with the saw operated and shut down the same way ?

 

[Mastermind]

I don't widen the intake side transfer on the xpw. The ring placement sucks but in a work saw I leave it.

Probably for the best.

I'm a firm believer that two rings will get the heat out of the piston, and into the fins better.

But.......most XPWs I do are saws that are not really worksaws in the true sense of the word.

 

[jmssaws]

Will you be able to peek into the lowers of both to compare residual oil ?
Keeping in mind that both saws would need to be operated the exact same way ?

A chainsaw can be operated close to the same but that's why comparing saws is really impossible to do,there are so many variables it's insane, my two saws are built as close as I can make them but my single ring saw is a good damn bit stronger than the other and it's not because of one ring,I've ran it with 2 rings,Its just simply a stronger saw,whatever reason that may be.

 

[Moparmyway]

A chainsaw can be operated close to the same but that's why comparing saws is really impossible to do,there are so many variables it's insane, my two saws are built as close as I can make them but my single ring saw is a good damn bit stronger than the other and it's not because of one ring,I've ran it with 2 rings,Its just simply a stronger saw,whatever reason that may be.

I agree, sometimes a chain is like that too .............. one is monumentally better than the other, yet both were done the same with the same specifics.

I am more curious as to the residual oil in the lower end on both when they are operated as close to each other as you can

 

[P.M.P.]

Not sure we covered this.Does one get more compression using 2 ring piston or 1 ring in the Husky 50mm?
Or let me put it this way more compression in a 371 or 372 which typically has more in stock form?

 

[jmssaws]

A high compression saw in cold weather can kiss my ass! I've broke the pull rope twice on my red light saw and haven't got it to hit yet.

I need some wire rope or a kick starter or a young weak minded individual to start these damn things.

 

[Moparmyway]

A high compression saw in cold weather can kiss my ass! I've broke the pull rope twice on my red light saw and haven't got it to hit yet.

I need some wire rope or a kick starter or a young weak minded individual to start these damn things.

I know EXACTELY what you are going through .................. exactely !!!
Do you have a rescue handle ............. ?

 

[jmssaws]

I've checked compression many many times comparing one ring to two and there's not much difference once broke in. Two new rings will make more than one new rings but after a tank there's not much difference.

 

[jmssaws]

I need to purchase stock in the company that makes this rope for stihl,maybe recoup some money.

 

[jmssaws]

I know EXACTELY what you are going through .................. exactely !!!
Do you have a rescue handle ............. ?

I like the old plastic small stihl handle,I've got a box of elastic ones that couldn't "handle" it. Get it? Lol