Another chainsaw dyno...

[MustangMike]

Thanks guys, that answers my question, a single ring Husky style piston is NOT necessary for great performance in these saws.

FYI, Meteor 460 pistons are slightly heavier and have slightly wider skirts than OEM. Dr. Al and I determined that a while ago.

 

[Bjorn]

Thanks guys, that answers my question, a single ring Husky style piston is NOT necessary for great performance in these saws.

FYI, Meteor 460 pistons are slightly heavier and have slightly wider skirts than OEM. Dr. Al and I determined that a while ago.

stock Stihl piston

 

[Bjorn]

Modified Husky piston,

 

[huskyboy]

Thanks guys, that answers my question, a single ring Husky style piston is NOT necessary for great performance in these saws.

FYI, Meteor 460 pistons are slightly heavier and have slightly wider skirts than OEM. Dr. Al and I determined that a while ago.

From what I can tell after running a few hybrids... the advantage with the single ring piston is that it vibrates less than the 460 piston. The reason being it is about the same weight as a stock 440 piston, which is what the crank was designed for. Crank longevity with the lighter piston is probably better. On the other hand the two ring 460 piston probably has better ring life. Just a guess. Now I don’t know about a performance advantage... the difference we are seeing is the different ways the saws were ported. To really test a performance advantage you would have to swap pistons on the same saw and dyno it.

 

[Bjorn]

From what I can tell after running a few hybrids... the advantage with the single ring piston is that it vibrates less than the 460 piston. The reason being it is about the same weight as a stock 440 piston, which is what the crank was designed for. Crank longevity with the lighter piston is probably better. On the other hand the two ring 460 piston probably has better ring life. Just a guess. Now I don’t know about a performance advantage... the difference we are seeing is the different ways the saws were ported. To really test a performance advantage you would have to swap pistons on the same saw and dyno it.

Hi, I think a singel ring Will hold about the same as a double, because it gets oil on both sides. On double ring its hard to get lubricant betwen the rings.

 

[Fruecrue]

From what I can tell after running a few hybrids... the advantage with the single ring piston is that it vibrates less than the 460 piston. The reason being it is about the same weight as a stock 440 piston, which is what the crank was designed for. Crank longevity with the lighter piston is probably better. On the other hand the two ring 460 piston probably has better ring life. Just a guess. Now I don’t know about a performance advantage... the difference we are seeing is the different ways the saws were ported. To really test a performance advantage you would have to swap pistons on the same saw and dyno it.

That swap is not directly possible if you desire meaningful results. Compression height is different.
Porting specifically for each piston may be different as well.
Best approach would be to take the best performing saws built with each and compare them.

 

[Dieselshawn]

This is why I love dynos. Really cuts down on the test time for testing different parts.

 

[Red97]

Go away for the weekend, find more saws to test when the dyno is fixed.

 

[cuinrearview]

I recognize the claw on that big mother frenchie on the right.

 

[mdavlee]

Go away for the weekend, find more saws to test when the dyno is fixed.

View attachment 248907

That 394 looks I’m like it has a muffler mod I did on it.

 

[huskihl]

That 394 looks I’m like it has a muffler mod I did on it.

We put that together this winter during a Sawsage Monster Garage session. Can’t remember if we did the muff mod or if it was already done.
@Fifelaker will know

 

[drf256]

From what I can tell after running a few hybrids... the advantage with the single ring piston is that it vibrates less than the 460 piston. The reason being it is about the same weight as a stock 440 piston, which is what the crank was designed for. Crank longevity with the lighter piston is probably better. On the other hand the two ring 460 piston probably has better ring life. Just a guess. Now I don’t know about a performance advantage... the difference we are seeing is the different ways the saws were ported. To really test a performance advantage you would have to swap pistons on the same saw and dyno it.

My hybrid has the 272 piston for this exact reason, matching the weight of a 440 piston. The crown has 40 removed from it, and it has one single 1.5mm Caber F-Cast ring vs 2 x 1.2 mm rings. The centered ring pin (over the intake) allows for fingers, which this saw had.

The 272 piston takes up less volume than a 460 slug, so it increases case volume. I expected more low end grunt from this, but the other two made more torque. This hybrid is around 180psi. It was done that way intentionally, as the user lives in the south and uses it for big cuts. As you all know, the more compression and heat, the more the saw will lean out as it gets hot and lose tune.

Mine is running a stock 17b and an OEM winter air filter with the foam element installed.

 

[Deets066]

The benefits of the 272 were originally the ease of running fingers and it let you get more intake. You don’t need to machine a lot to get your trans and intake right with a 46 piston. So that left you grinding down to get 79-80, whatever your target is. To grind the intake with good shape and lower that far, it was very easy to grind through. Thus, the reason for the 272.
I never thought my hybrid vibrated more than a 440 or 460. To each their own though.

 

[Fifelaker]

That 394 looks I’m like it has a muffler mod I did on it.

We put that together this winter during a Sawsage Monster Garage session. Can’t remember if we did the muff mod or if it was already done.
@Fifelaker will know

I did that mm shortly after I got the sawinabox.

 

[Cobby08]

I tried skimming, did you end up having to order parts for the dyno or is this an in house fix?

 

[Cobby08]

P.S. @Red97 boat anchor should be arriving today.

 

[Red97]

I tried skimming, did you end up having to order parts for the dyno or is this an in house fix?

Parts order, would like to have it by the end of the week.

 

[mgr1]

Parts order, would like to have it by the end of the week.

We all want you to have it end of the week.

 

[Red97]

Shipping label was created.

Have 5 other deliveries to deal with this week first. May be a slow saw week...

 

[Dieselshawn]

Should try a saw running a pipe and nitromethane on the dyno

Those saws always seem to make awesome looking videos while cutting wood.

While my pipe and pump gas made less power than the muffler on the 260, the saw sounded awesome and had neighbouring farms phoning in asking what’s going on over there