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I've read that Husqvarna has a cast iron impeller which is heavier than a "typical" impeller.
I think I read on a few instances, but I also spoke to a small engines mechanic at a Husqvarna dealer (He is a friend of mine) about that and he says that the heavier impeller would give it a better performance after it gets going since it would have or keep a "momentum" ?

Can someone explain this better.
Is this true?
Would a heavier impeller have an impact on the blowers performance?
 

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I think it's probably a yes and no question. Think about swinging a hammer around on a rope. then think about swinging a a sledge. Which one do you think make the most impact? Which one is easier to swing...... same deal. The sledge will definitely have more power once you finally get it going. It will be tougher on the engine to keep it going. Does the engine have the staying power in deep heavy stuff with the heavier impeller is the question. I'd like to think they considered that in the design....
 

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The "momentum" thing I don't buy. Not that it isn't true, I just don't think it would matter.

It's probably not practical to test this but try to imagine: suppose that with the machine in normal operation (meaning engine @ full speed and auger/impeller engaged) you disengaged the impeller clutch and immediately shoved the machine into a foot of wet snow. How long would the impeller take to stop? A fraction of a second?

Now imagine what would happen if the impeller weighed, say, twice as much. How long would that impeller take to stop? IMHO it would be a slightly longer fraction of a second.

My point being that the loads a snowblower impeller sees vary in timeframes of seconds or minutes, and a the extra weight of a cast iron impeller just isn't likely to matter in that context.

But I can see a couple of other advantages. It would make the front of the snowblower a bit heavier for those who want that. And it might be stronger, meaning the vanes would be less likely to bend back when they have to deal with rocks and things. OTOH cast iron is much more brittle than steel, so in such a case it's also possible a cast iron impeller would crack whereas a steel one would bend.
 

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"Which one do I think will make the most impact"? The one that lands on your head after swinging it around on the rope... :laugh:

I think it's probably a yes and no question. Think about swinging a hammer around on a rope. then think about swinging a a sledge. Which one do you think make the most impact? Which one is easier to swing...... same deal. The sledge will definitely have more power once you finally get it going. It will be tougher on the engine to keep it going. Does the engine have the staying power in deep heavy stuff with the heavier impeller is the question. I'd like to think they considered that in the design....
 

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seeing that the impeller doesn't freewheel on the impeller shaft it shouldn't make a difference if the impeller is cast or not
 
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A heavier piece of metal would add a slight amount of extra "flywheel" effect, but since it's an impeller, and there are forces acting on it to slow it down all the time, (snow) I somehow doubt that this would make any difference in performance. While is spinning slower with load, the engine has to provide that much more power to get it back up to speed. Now, a larger diameter impeller might make a difference, but cramming that into an existing housing might be a challenge

I need another coffee, hard to think like a flywheel or an impeller this early
 

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A heavier piece of metal would add a slight amount of extra "flywheel" effect, but since it's an impeller, and there are forces acting on it to slow it down all the time, (snow) I somehow doubt that this would make any difference in performance. While is spinning slower with load, the engine has to provide that much more power to get it back up to speed. Now, a larger diameter impeller might make a difference, but cramming that into an existing housing might be a challenge

I need another coffee, hard to think like a flywheel or an impeller this early
seeing that the impeller is belt driven about any flywheel effect would be taken up by the belt slipping
 

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Either that, or it'll just add to the flywheel effect of the motor.

I guess for me, I might rather have a cast-iron impeller if the alternative was a poorly-constructed steel one. But if the other option was an impeller made of reasonably thick steel and braced well, that's what I'd choose.
 

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An idea like this probably comes from the marketing department.

Marketing: "Will a heavier impeller result in better performance?"

Engineering: "Well, its a complicated question..in theory more weight will result in slightly more torque, but an imperceptible amount, and it depends on engine strength, because the engine has to overcome the weight, and belts are a factor, and many other things will impact the question, and also..." (rambles on for 10 minutes)

Marketing: "But it will technically result in more power?"

Enginnering: "perhaps, in theory..but probably not enough to be meaningful."

Marketing: "ok, thanks!"

Advertisement: "Our heavier impeller results in better snow throwing performance!"

I am NOT saying any manufacturer has done that! ;)
The above was fiction..
but I can see things like that happening, in every industry and with any product.

Scot
 

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For what it's worth... from their sales literature, it seems they're promoting its durability, not its performance:


And it's got 4 blades! Like 2 weeks ago, and not like last week's model that had 3. :icon_whistling:
 
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I'm with the shouldn't make a difference camp as far as performance. Having a lighter impeller allows the engine to speed it back up sooner should it get loaded and start to drop RPMs.
I'd also rather the impeller jammed and the belt spun or the pin breaks rather than the "sledge" (rotational mass) seeing if the impeller lives or the chunk of ice, newspaper, brick, branch, ... does :wacko:

I would hate to crack it or break a chunk off as cast is a pain to try and weld. I like steel better from a repair standpoint too.
 

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For what it's worth... from their sales literature, it seems they're promoting its durability, not its performance:


And it's got 4 blades! Like 2 weeks ago, and not like last week's model that had 3. :icon_whistling:
My craftsman is a husqvarna in red paint. It's got a 3blade, steel with welded in gusset plates, and it seeme to be pretty durable so far. I wonder how many people break impellers?
 

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Seems very few bend them. Thank shear pins or the small roll pins that let go first !!
 

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Impellar size ,shape ,and speed would have a performance effect but not weight. Light or heavy the impellar speed is related to sheave rpm and there is no slip there. I wouldn't want to be the guy removing a cast iron impellar in one piece
frozen to a shaft, or be blowing snow in -20 weather and introduce anything solid into the impellar.
 

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I wouldn't want to be the guy removing a cast iron impeller in one piece frozen to a shaft.
What??? No spirit of adventure. Just think of all the new phrases you could coin during the process!
 

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A few things concerning Husky's cast iron impeller is for one they have a 12" impeller and Ariens is 14" so I would doubt a big discrepancy of weight between the two. Cast iron has good compressive strength but relatively poor tensile strength but the fact you can melt it in any shape can overcome its tensile shortcoming. JMO
 

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The distance the snow is thrown is directly related to the speed of the snow particles when they come off of the impeller, whether the impeller is heavy or lightwweight, and that speed should be the same as the impeller speed at the moment the snow separates from the impeller. A heavy impeller won't run at a faster rpm and would work the engine harder than a lightweight impeller. If you had 2 identical snowblowers - one with a heavy impeller installed, and the other with the light impeller, I think the governor would control the engine speed to the same rpm regardless of which impeller is installed, consequently, given the same snowblowers, and throwing the same snow, but with 2 different weight impellers, won't change the throwing distance. One engine will work harder than the other in the process, however.

If you install an impeller kit, you lengthen the impeller radius by the length of the rubber sticking out beyond the edge of the original impeller, and consequently that add'l impeller radius results in add'l speed at the outer edge of the impeller given the same impeller rpm, so the snow flies further.

Another way to look at this question is to compare snow throwing distance to how far a golf ball can be hit. Most drivers have the same coefficient of restitution, so consequently, the statistic everybody talks about, related to how far the ball can be hit, is club head speed. No one in the golfing world ever talks about the weight of the club a golfer uses as an indication of how far the ball is hit. The weight of the club, however, affects how fast you can swing the club, and consequently, how fast the club head speed is. I've never heard anyone say that if there are 2 golfers who have the same club head speed, that one of them can hit the ball further than the other because his driver is heavier.

Time for a good stiff drink.
 

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It probably cast steel not cast iron. And if it's the same thickness as the regular welded impeller then there no significant weight difference.
 

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The distance the snow is thrown is directly related to the speed of the snow particles when they come off of the impeller, whether the impeller is heavy or lightwweight, and that speed should be the same as the impeller speed at the moment the snow separates from the impeller. A heavy impeller won't run at a faster rpm and would work the engine harder than a lightweight impeller. If you had 2 identical snowblowers - one with a heavy impeller installed, and the other with the light impeller, I think the governor would control the engine speed to the same rpm regardless of which impeller is installed, consequently, given the same snowblowers, and throwing the same snow, but with 2 different weight impellers, won't change the throwing distance. One engine will work harder than the other in the process, however.

If you install an impeller kit, you lengthen the impeller radius by the length of the rubber sticking out beyond the edge of the original impeller, and consequently that add'l impeller radius results in add'l speed at the outer edge of the impeller given the same impeller rpm, so the snow flies further.

Another way to look at this question is to compare snow throwing distance to how far a golf ball can be hit. Most drivers have the same coefficient of restitution, so consequently, the statistic everybody talks about, related to how far the ball can be hit, is club head speed. No one in the golfing world ever talks about the weight of the club a golfer uses as an indication of how far the ball is hit. The weight of the club, however, affects how fast you can swing the club, and consequently, how fast the club head speed is. I've never heard anyone say that if there are 2 golfers who have the same club head speed, that one of them can hit the ball further than the other because his driver is heavier.

Time for a good stiff drink.
im sure glad it doesnt snow golf balls.:wavetowel2:
 
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