What oil is best? and what ratio?

[mrxlh]

Ever tried only running the bottom ring? There’s not much there to help with any added pop

Try it using the top ring…

 

[huskihl]

Try it using the top ring…

I have. Depending on what the customer wants, sometimes I leave the bottom one out

 

[mrxlh]

Something to consider is that the ring gap between the 1st and 2nd ring is the same, so the amount of blow-by is also the same. Whatever is getting past the top ring, is also getting past the second ring..

The amount of blow by is not the same from a single ring to a double ring. Everyone measures compression, not leak down, there is a reason why they went to 2 rings. What leaks by under compression fouls the next charge, what’s being compressed in the bottom end also leaks by on the way out as unburned NMHC.

 

[jakethesnake]

Any good? I mentioned it before but that raisman full synthetic they sell at hL seemed to be pretty good stuff. I used it up and found a few bottles of this stuff I had hoarded. Current blend

 

[PissRev]

View attachment 368192Any good? I mentioned it before but that raisman full synthetic they sell at hL seemed to be pretty good stuff. I used it up and found a few bottles of this stuff I had hoarded. Current blend

It's very good. It's basically the same thing as Citgo air cooled oil. I've burned a pile of it.

 

[Wilhelm]

Sachs-Dolmar 105 1988-2006. on pump gas (then leaded, regular, non-ethanol) and 15W40 tractor 4-stroke engine oil at 25:1 and UP.
I bucked firewood logs with this little 40cc top handle saw.
I had no idea what a sharp chain is and burned up bars and wore through the chains tie straps before wearing out the cutters.
PH had never been torn down!
No horsefly's nor mosquito's either.

Carbon buildup?
I didn't even know something like that existed back then!

When in doubt, add more oil!
Better to flush a 2-stroke PH with too much oil rather than run it on straight gas.

I am still running Makita red 50:1 oil @ 40:1.

Last year I tried some blue Dolmar full synth that I got from Andrew @ajschainsaws with a saw purchase and it is good - wouldn't mind having some in stock of that.
Also tried some Würth and it burns my nostrils and makes me cough really bad - I am NOT gonna get any of that!

At this point I am considering to source another full case of red Dolmar/Makita oil and be set for the next decade or so.

 

[full chizel]

* I'm not starting an oil war. Please don't take it personally. I'm trying to have a legitimate discussion with reasonable adults.

Did you forget where you were FFS?

 

[Duce]

but seriously, it would be an interesting experiment. take a new 572 or whatever and run it on 30 weight and see what happens.

You buy that 572, send it here and I will run it that way. No problem!

 

[Duce]

I understand that. I was more or less refering to friction changes. Just wondering if one would respond better, or if they would be the same. If one would have bigger reaction to less friction. I might just be spitting in the wind.

In my snowmobile I have switched from the factory single ring to double ring for the added heat transfer. The single rings had problems on long hard pulls of over heating and flaking. But, you do loose a little power and faster reving with it.

Might just be useless rambling on my part.

Single ring Husky 372's is thicker than 2 rings epa piston. Does that make a difference?

 

[Duce]

I have. Depending on what the customer wants, sometimes I leave the bottom one out

Do all single ring pistons have a thicker ring?

 

[Duce]

View attachment 368192Any good? I mentioned it before but that raisman full synthetic they sell at hL seemed to be pretty good stuff. I used it up and found a few bottles of this stuff I had hoarded. Current blend

How many oils are bottle at same plant. Same formula, same color, close to same labeling. Father-in-law worked at Milford jelly plant and produced jelly labeled under many different brands, he set up label machines. Later a Howell plant offered him more money to set up their labeling machines, bottled oils, additives, waxes and cleaners for many different brands. Husqvarna and Dolmar bottles and contents looked the same, much like that bottle.

 

[Powerstroke Cowboy]

Single ring Husky 372's is thicker than 2 rings epa piston. Does that make a difference?

Yes. A thinner ring has less friction compared to a thicker ring. Think surface area.

 

[Duce]

Yes. A thinner ring has less friction compared to a thicker ring. Think surface area.

How about heat transfer from piston to cylinder?

 

[MustangMike]

Two rings will provide more friction but will also seal better than one ring.

Think of it like this, if the ring gap lets 10% pressure by, and the second ring lets 10% pressure by (note: these are made up #s) the net to get by is only 1%.

I'm not saying what is better in a specific application ... just providing some info.

 

[Mastermind]

Two rings will provide more friction but will also seal better than one ring.

Think of it like this, if the ring gap lets 10% pressure by, and the second ring lets 10% pressure by (note: these are made up #s) the net to get by is only 1%.

I'm not saying what is better in a specific application ... just providing some info.

You sound like an accountant Mike.

LOL

 

[Powerstroke Cowboy]

How about heat transfer from piston to cylinder?

Dual rings have more contact (surface area) with the piston. So they should have a better ability to pull heat off the piston.

 

[Mastermind]

Like Kevin said earlier, the two ring pistons are really more about heat transfer than anything else.

Here's another thing to swish around in your brain.

Why does Stihl use a form of air injection on many saws....but not on the 500i, 661, and 881?

 

[Duce]

Like Kevin said earlier, the two ring pistons are really more about heat transfer than anything else.

Here's another thing to swish around in your brain.

Why does Stihl use a form of air injection on many saws....but not on the 500i, 661, and 881?

It's all about the money. They will not last as long and you buy another.

 

[farminkarman]

Like Kevin said earlier, the two ring pistons are really more about heat transfer than anything else.

Here's another thing to swish around in your brain.

Why does Stihl use a form of air injection on many saws....but not on the 500i, 661, and 881?

Idk, probably need all the air from the fan for cylinder cooling.

 

[Mastermind]

Idk, probably need all the air from the fan for cylinder cooling.

Spot on. Rather than be overly concerned about the air filter needed to be cleaned regularly, the engineers at Stihl realize that these bigger saw engines need all the cooling power that the flywheel can provide.