[orangputeh]

it's almost impossible to attain a perfect seal as the inside housing is NOT a perfect circle . You can get pretty close. and important step is breaking in your pads. if you do it "dry" the pads will melt from the friction and may be damaged , split , etc and may have to be redone.

so you should use some kind of lubrication ( i use fluid film but other lubes will work ) and proceed slowly at first so the pads will wear in. I have posted this before. I have two Honda HS80's that I experimented with. One with kit and one without and waited for a wet slushy snowfall.

we had about 6 inches of it so tried out both blowers. the one without the kit clogged up every 3 feet or so. the one with the kit threw the snow and water 10-15 feet. under dry powder conditions the results were similar. the one without the kit threw the dry powder very well as it always did but the one with the kit threw the snow further.

the efficiency is improved. you in effect have a water pump now.

 

[Ziggy65]

it's almost impossible to attain a perfect seal as the inside housing is NOT a perfect circle . You can get pretty close. and important step is breaking in your pads. if you do it "dry" the pads will melt from the friction and may be damaged , split , etc and may have to be redone.

so you should use some kind of lubrication ( i use fluid film but other lubes will work ) and proceed slowly at first so the pads will wear in. I have posted this before. I have two Honda HS80's that I experimented with. One with kit and one without and waited for a wet slushy snowfall.

we had about 6 inches of it so tried out both blowers. the one without the kit clogged up every 3 feet or so. the one with the kit threw the snow and water 10-15 feet. under dry powder conditions the results were similar. the one without the kit threw the dry powder very well as it always did but the one with the kit threw the snow further.

the efficiency is improved. you in effect have a water pump now.

Do you think the impeller mod is worth doing if you have about 1/4" gap?

 

[squid3083]

You're mistaken :kiss:

I used 2 ply baler belting (from Tractor Supply) and, for me, it was a perfect balance between being supple enough to match the contours of the housing wall and strong enough to last a lot of use. Plus, being supple means the belting can be pushed right up against the housing wall completely closing the gap. I did experiment with other materials and most were far too rigid.

https://www.tractorsupply.com/tsc/product/wcco-belting-baler-belting-2-ply-4-in-x-60-in

For the slippery stuff I use white lithium spray. I do have a job lot of it to use but have still found it the best.

Here is a picture from inside my housing showing the belting bending just enough to hug the housing wall.

Well you are right and wrong at the same time lol

I can see that it bends and is more supple then my mud flap.

But the area we were talking is making the inside bend width wise inside the impeller, not just the big flat part of the impeller but the left side of the impeller. (hope you understand)

I can do that with my mud flap but there is a gap. But can probably do it with your belt strap ... depends on thickness nag how well it can hug that curb.

As for hugging the outside of the impeller. It was touching directly, and offerred too much resistance to my taste. So I went with very minute gap and almost no resistance.
Less wear and strain on belts and motor.

Don't have exact measurment but my mud flap seems twice the thickness so does'nt help for the bending but should be very sturdy.

 

[SkunkyLawnmowers]

Do you think the impeller mod is worth doing if you have about 1/4" gap?

I know you were asking somone else but......

Mine was clogging with a 5/16" gap. With the impeller mod - no clogging at all.

I have a theory that tighter impeller end gaps actually accelerate and promote clogging. Can't prove it yet but I am working on it!

 

[orangputeh]

Do you think the impeller mod is worth doing if you have about 1/4" gap?

it all depends on past performance in my opinion. have you had problems with clogging? do you coat the inside bucket and chute with a non stick product? I have only done about a dozen but in each case the cap was at least 3/8th of an inch.usually more so the mod was a good improvement . I haven't done them on the bigger Honda HS1132's because hardly have any issues with clogging.

1/4 inch is not bad . i'm not sure the increase in efficiency would be noticeable. did you post what HP and size your machine is?

 

[squid3083]

Do you think the impeller mod is worth doing if you have about 1/4" gap?

What brand do you have that has 1/4 gap ???
Is it min 1/4 all around ??
This is my first mod lol but with what I've seen the bigger gap, the better result, mine was 3/4.
Huggggggeeeee difference and changed auger belt and auger cable.

the more round shape you have opposed to egg shape, the better.
Would expect if you have min 1/4 all around, and you trim it very close or touching barely with lubrication , You should see a difference.

 

[squid3083]

I know you were asking somone else but......

Mine was clogging with a 5/16" gap. With the impeller mod - no clogging at all.

I have a theory that tighter impeller end gaps actually accelerate and promote clogging. Can't prove it yet but I am working on it!

Glad you answered, excellent example !!!!

 

[squid3083]

For the slippery stuff I use white lithium spray. I do have a job lot of it to use but have still found it the best.

Just finished a can of lithium spay yesterday. Wasn't sure it would be the best or last with all the snow and ice going through the housing and the impeller.

Doing a test outside and going to hardware store BMR to buy a can this afternoon.

 

[squid3083]

I know you were asking somone else but......

Mine was clogging with a 5/16" gap. With the impeller mod - no clogging at all.

I have a theory that tighter impeller end gaps actually accelerate and promote clogging. Can't prove it yet but I am working on it!

Did you see a big difference in the normal snow for throwing distance ???
And what brand of thrower do you have ??

 

[SkunkyLawnmowers]

Did you see a big difference in the normal snow for throwing distance ???
And what brand of thrower do you have ??

I have a HSS724AWD - that's a 2017 24" 2 stage wheeled Honda - aka Parker

I would love to give you more feedback & data but unfortunately since doing my modification we've hardly had any snow at all, just an inch or two in the last few seasons. However, I can say that I have maybe used him twice since the mod in slushy wet icy goop and absolutely no clogging. Before the mod, in those conditions, he would clog within minutes.

 

[Tony P.]

Do you think the impeller mod is worth doing if you have about 1/4" gap?

The impeller mod. is very much a matter of diminishing returns. Correcting a gap from 1/4" to zero is often negligible compared to going from 1/2" to 1/4".

Beyond that, the answer depends on how you define 1/4" gap. The housing isn't perfectly round, so a 1/4" at the narrowest point will be less beneficial than a 1/4" correction where the gap is 3/8" at other points.

In addition, using a lubricant provides some benefit, as well.

Finally, there's a reality here that any snow blower will work better under some conditions than it will under others.

 

[DickR]

I'm in my third season with my Husqvarna ST227P (254cc engine). It moved even "good snowman" snow fairly well, although too wet and I'd wind up re-blowing a lot of the snow in the wide part of the driveway outside the garage, where it flares out to pass also by the side of the garage. But after a storm that dropped an inch or two of snow and then enough rain to leave a half inch of slush at the bottom, I had to handle the mess with the push plow. Otherwise the blower would clog too often, and in between clogs the soggy mess would dump out just a couple of feet to the side. After stalling too long and putting up with doing the slushy jobs by hand, I bought the materials and did the impeller job.

Following a link from another thread on impeller mods, I bought a 3-ft roll of 4" wide 1/4" SBR; the label reads "70 S Shore A, Black, Smooth Finish, No Backing." I found a source of 40x80 mm stainless mending plates online, and from the hardware store I got 1/4" stainless bolts with locking nuts.The bolts are 3/4" long, but I should have used 1" to make it easier to get the nuts on in tight quarters. Below are pics I took this afternoon, with the chute removed. The top two pics show the bolt head side, as the impeller blade is about to pass the chute area. You can see how I bent each plate up to hold the rubber piece as it turns up the curvature of the blade. The first also shows where I notched the rubber where it passes over the chute bolts. The third pic shows the back side of the blade, where the nuts are fastened, and the stiffening groove in the blade. The groove was convenient for starting the bolt holes. I suppose drilling twice in the groove weakens the blade, but that would be offset by having the plate/rubber sandwich bolted on. I used a new 5% cobalt bit at slow speed for the drilling, with the chute off, with an old round cold chisel placed through a chute bolt hole to hold the impeller from turning as I leaned on the drill. A strong magnet was used afterward to clean up the bits of drilled out steel from the housing. The first and third pics also show that the rubber turns up the end of the blade, but not all the way to the tip. The end of the rubber does go outside the chute opening, so I'm not concerned about spillover there.


The last pic shows the can of spray stuff that Tractor Supply sold me when I asked about what they'd recommend to make the inside of the bucket non-stick. It seems to do the job well.


After finishing the job, I took the machine outside and started the engine. After a bit of warmup, I engaged the drive, and I did notice a brief bit of laboring as the impeller was driven around the housing. I didn't run it for too long that way. I figured that the roughness of the housing interior, due to small stones and other crud from two years of blowing, would file down the edges of the rubbers pieces in short order.


Given the snow drought we're having here in NH this year, the only test of the modified machine was in 4-5" of very light snow. Whether it performed better on that stuff is hard to say, as that type of snow sort of aerates quickly ten feet out of the chute and disperses. I'm waiting for something heavier to fall. We've had maybe 3" of light snow today, but tomorrow we're due for some sleet and freezing rain, then maybe back to snow at the end. I'll wait for the end of that, then see what happens to the combination of snow and ice.


An earlier post commented on improved chute velocity. I thought I'd add my own. With an unmodified impeller, snow/slush right at the tip of the impeller should be near the speed of the impeller itself. But right next to the housing, the drag of the housing would slow the speed of the snow considerably, to a fraction of impeller speed, notably when the snow is really sticky or slushy. In between impeller and housing, snow speed would be somewhere in between, falling off rapidly outside of the impeller tip. This layer of reduced-velocity snow/slush likely is what leads to increased chute clogging. Thus it's easy to imagine why having a rubber piece sweeping up snow right to the housing would nearly eliminate that low velocity layer and improve the throw. I doubt that the slightly higher velocity of the very tip of the rubber compared to that at the tip of the impeller blade has a lot to do with the improvement. I think it's mainly the elimination of the low-velocity layer that does the trick.


[Moderator: given that this thread has grown in length considerably and is mostly about impeller modification and not really specific to Honda blowers, should it be moved to the maintenance/repair forum?]

 

[Ziggy65]

I know you were asking somone else but......

Mine was clogging with a 5/16" gap. With the impeller mod - no clogging at all.

I have a theory that tighter impeller end gaps actually accelerate and promote clogging. Can't prove it yet but I am working on it!

Thanks for the response. Let me know how your investigation goes.:smile2:

it all depends on past performance in my opinion. have you had problems with clogging? do you coat the inside bucket and chute with a non stick product? I have only done about a dozen but in each case the cap was at least 3/8th of an inch.usually more so the mod was a good improvement . I haven't done them on the bigger Honda HS1132's because hardly have any issues with clogging.

1/4 inch is not bad . i'm not sure the increase in efficiency would be noticeable. did you post what HP and size your machine is?

The machine is a 1967 10000 series Ariens with original 5hp tec/ 24". It has never really had problems clogging, but just spews the really wet stuff a couple of feet. My main goal would be increasing throwing distance of "normal" snow, it throws around 20 feet or so presently.
I spray chute and bucket with fluid film, which does help and plan on sanding and painting the chute this spring. Installed a tach on it a month or so back, as well as new carb and belt. The RPMs had been running around 3200, probably for many years. Increased RPMs to about 3450 and the old girl definitely throws snow farther now. Haven't really been able to give it a real test for lack of snow the past month or so.

My main blower is a Ariens 28 SHO and performs fine with out the mod, but I had an MTD for a short time that had a gap of at least 1/2" and the impeller kit I installed made a huge difference in it's ability to throw snow.

I know the old Ariens is a little under powered and would benefit from a taller chute, so I don't expect same performance as the SHO or a Honda. My gut is telling me I won't notice much difference, but I am always glad to listen to others opinions and experiences.
Thanks

 

[Snowbelt_subie]

We arent working on the space shuttle they are just snowblowers.

Put some rubber on the impeller get it as close as you can and you will be fine.

It works wonders on all blowers I've done them on ariens, mtds, hondas. They all have noticeable improvement and no clogging.

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[Spawn.Qc]

Hey guys, you can take my opinion with a grain of salt, I’m just a high school history and sciences teacher, not a rocket scientist!

My take is that under some conditions, a bit of an impeller gap can be beneficial ... bear with here:

Our engine can only produce a finite amount of power, and that power (amount of work accomplished over a given time) is a product of torque (force) and rpm (how often this force is produced every minute)

Now I can see how impeller gap effectively creates a “leak” in the pumping action where we are using engine power to push snow through a duct. For this effect we are trying to :
- accelerate the snow to maximum speed in order to obtain good throwing distance and avoiding clogging...
-maximize the quantity of snow we are removing from the auger box to avoid bogging and overspill as we move, ideally being able to take full swath as we go to fully use this auger width.


Now, although air and snow are consider fluids in mechanical science (I know, air is a gas, snow is a solid) we cannot fully compare our impeller with water pumps impellers...
Our snow blower impellers are more an hybrid between pump impellers and air screw (propellers). This means that a certain ratio of air in our impeller will not cause a drastic drop in pumping efficiency not any increases in cavitation. In fact, due to its very low density, a certain amount of air intakes allows to reduce load, effectively keeping the impeller RPM into its optimal working range. (Engine rpm as well since these two are mechanically linked by a belt)
You can compare the effect of air in the snow/air mixture here with a torque converter in your automatic transmission... (you might not like the mushy feeling of AT in your car, but there is no denying it does multiplies the torque force applied to wheels at low engine rpm!)

Now, can impeller gap mods be helpful? Yes! It can increase throwing distance, it can help prevent clogging (very wet snow behave more like water than dry powdery snow). This is very true in not so well engineered snow blower(I used to have a very bad craftsman )
The down side: you are now at risk of overloading your engine power due to the extra mass (pure snow is denser than snow mixed with air) of the snow that must be lifted and accelerated by your impeller at the passage of every impeller blades...

Would I recommend such a mod on Honda’s and Yamahas? Nope... not on mine... Honda engineers spent a lot of time balancing the ratio of snow/air (efficiency) of the impeller to make sure it grabs enough snow to empty the buck as fast as the auger can feed it while still sucking enough air to maintain rpm and accelerate the mixture to speed in the chute.

So how to know if you can benefit from such a mod?
Use these question:
Could I used extra throwing distance?
Is my bucket always spilling of the side as soon as I take full width swath?
Am I often dealing with water, extra wet snow?
If you answer yes to any of the above, chances are that increasing the scooping volume of the impeller would help you.

Last note of the throwing distance:
Increasing the impeller rpm (pulley ratio) would be more efficient as it will increase both the snow and air moved in the chute.. it will also avoid risking premature bearing damages due to improperly balanced impeller...

All right, I’m braced, you can flame me now...


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[Tony P.]

Our engine can only produce a finite amount of power, and that power (amount of work accomplished over a given time) is a product of torque (force) and rpm (how often this force is produced every minute)

While that's true of the engine, it's not true of the entire snow blower because speed/volume should also be considered.

Spawn.Qc, let me take exception to one component of what I think you're saying: the premise that the impeller modification relates to increasing the volume of snow moving through the snow blower. I don't think that's the issue particularly as the modification increases the impeller blade by only around 3/8".

The fact is that the volume of snow is related most closely to the speed of the snow blower. A snow blower moving twice as fast will handle twice as much snow so the user is always able to control volume, perhaps subconsciously. Likewise, at any speed, the snow blower handles the amount of snow moving into the auger irrespective of whether or not the snow blower has been modified.

So, it's a question of effectiveness, rather than volume. The modification improves the snow blower's efficiency and reduces clogging, which translates into effectiveness. In that way, I believe modifying the impeller also reduces stress rather than increasing it

 

[Spawn.Qc]

While that's true of the engine, it's not true of the entire snow blower because speed should also be considered.

Spawn.Qc, let me take exception to one component of what I think you're saying: the premise that the impeller modification relates to increasing the volume of snow moving through the snow blower. I don't think that's the issue particularly as the modification increases the impeller blade by only around 3/8". The fact is that the volume of snow is related most closely to the speed of the snow blower. A snow blower moving twice as fast will handle twice as much snow so the user is always able to control volume, perhaps subconsciously.

The modification improves the snow blowers efficiency and reduces clogging. In that way, I believe modifying the impeller reduces stress rather than increasing it

A few points on this:

3/8th of an inch over the width of the impeller blade is a substantial area, multiplied by all three or four blade is quite something. At the outside of the the impeller radius is HUGE in terms of impact due to the leverage and blade speed effect.

Now let say: If you scoop 50grams of snow per impeller revolution at 2000rpm , you can move the same amount of snow at 1000 impeller rpm by scooping 100grams of snow per revolution but: the amount of mechanical stress is exactly twice on the parts and engine. Exact same work done, twice as stressful on the parts.. this is why shaft torque was closely monitored in airplane big radial engines.. I digress a bit.

I agree 100% with you that it will reduce clogging. I partially agree with you on the efficiency part. 3/8th of an inch gag or bigger? Yeah, might wanna reduce this gap... closing the gap completely? Not so sure.. some breathing space in that mechanical system is not necessarily an complete efficiency killer... i have faith Honda engineers could have designed those blower with near zero gap...there is a real need for “play” to account for various snow conditions...

Any how, I’m not trying to say that there is no application for the mod, It’s just not a 100% magical mod , as far as I understand physics at play...


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[Tony P.]

3/8th of an inch over the width of the impeller blade is a substantial area, multiplied by all three or four blade is quite something. At the outside of the the impeller radius is HUGE in terms of impact due to the leverage and blade speed effect.

Now let say: If you scoop 50grams of snow per impeller revolution at 2000rpm , you can move the same amount of snow at 1000 impeller rpm by scooping 100grams of snow per revolution but: the amount of mechanical stress is exactly twice on the parts and engine. Exact same work done, twice as stressful on the parts.. this is why shaft torque was closely monitored in airplane big radial engines.

Of course I agree with what you're saying but can't follow how this relates to the impeller mod. Let me know what I'm missing.

The volume of snow and impeller RPMs are a function of the snow depth and snow blower speed, not the size of the impeller blade. When the user sets the speed, the snow blower will collect and move snow at the rate selected irrespective of whether or not the impeller is modified.

Likewise, the volume of snow handled by the impeller is purely a function of the rate of snow delivered by the auger. Increasing the size of the impeller blade doesn't change that.

 

[DickR]

At any forward speed of the blower, the effort provided by the engine will ramp up to accommodate the load. I hear this when I move from a layer of undrifted snow into a drift several times deeper. A blower ought to handle the load well through a foot of dry snow, if only in low forward speed, with the engine delivering the necessary power. Otherwise the machine is underpowered in the first place. So it ought to move just as well through a 2" layer of wet/slushy snow having the same total water content and thus same mass as the dry foot, without overloading the engine. Trying to move the machine through a foot of sopping wet snow would be asking too much (unless the machine is really some beast built for it). Somewhere in between there might be a point where adding 3/8" to the impeller diameter would reach the point of overload.



It's interesting to compare this to centrifugal liquid pumps, for which a mfg provides pump curves. A range of different diameter impellers can be used within any casing. For any impeller diameter and rotational speed, the pump will operate on that curve, and pump head will vary with volume flow. As volume goes down, head goes up. Pump power requirement also will vary along the curve. In sizing a pump, one picks the appropriate curve according to volume and head requirements, and that determines the required driver power.

 

[Shovel]

Hey guys, you can take my opinion with a grain of salt, I’m just a high school history and sciences teacher, not a rocket scientist!

My take is that under some conditions, a bit of an impeller gap can be beneficial ... bear with here:

Our engine can only produce a finite amount of power, and that power (amount of work accomplished over a given time) is a product of torque (force) and rpm (how often this force is produced every minute)

Now I can see how impeller gap effectively creates a “leak” in the pumping action where we are using engine power to push snow through a duct. For this effect we are trying to :
- accelerate the snow to maximum speed in order to obtain good throwing distance and avoiding clogging...
-maximize the quantity of snow we are removing from the auger box to avoid bogging and overspill as we move, ideally being able to take full swath as we go to fully use this auger width.


Now, although air and snow are consider fluids in mechanical science (I know, air is a gas, snow is a solid) we cannot fully compare our impeller with water pumps impellers...
Our snow blower impellers are more an hybrid between pump impellers and air screw (propellers). This means that a certain ratio of air in our impeller will not cause a drastic drop in pumping efficiency not any increases in cavitation. In fact, due to its very low density, a certain amount of air intakes allows to reduce load, effectively keeping the impeller RPM into its optimal working range. (Engine rpm as well since these two are mechanically linked by a belt)
You can compare the effect of air in the snow/air mixture here with a torque converter in your automatic transmission... (you might not like the mushy feeling of AT in your car, but there is no denying it does multiplies the torque force applied to wheels at low engine rpm!)

Now, can impeller gap mods be helpful? Yes! It can increase throwing distance, it can help prevent clogging (very wet snow behave more like water than dry powdery snow). This is very true in not so well engineered snow blower(I used to have a very bad craftsman )
The down side: you are now at risk of overloading your engine power due to the extra mass (pure snow is denser than snow mixed with air) of the snow that must be lifted and accelerated by your impeller at the passage of every impeller blades...

Would I recommend such a mod on Honda’s and Yamahas? Nope... not on mine... Honda engineers spent a lot of time balancing the ratio of snow/air (efficiency) of the impeller to make sure it grabs enough snow to empty the buck as fast as the auger can feed it while still sucking enough air to maintain rpm and accelerate the mixture to speed in the chute.

So how to know if you can benefit from such a mod?
Use these question:
Could I used extra throwing distance?
Is my bucket always spilling of the side as soon as I take full width swath?
Am I often dealing with water, extra wet snow?
If you answer yes to any of the above, chances are that increasing the scooping volume of the impeller would help you.

Last note of the throwing distance:
Increasing the impeller rpm (pulley ratio) would be more efficient as it will increase both the snow and air moved in the chute.. it will also avoid risking premature bearing damages due to improperly balanced impeller...

All right, I’m braced, you can flame me now...


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I will bite.[emoji1]
I will start with the torque converter comparison.
A torque converter redirects the fluid to another set of vanes to increase torque..
An impeller in our machines with snow going around the impeller would be a comparison to a slipping clutch.( Converts to heat as wasted energy)
Maximum work. Peak HP in theory is where we can achieve maximum work (moved snow).
Those tests are done in labs holding the governor open...In real life we have governor droop/ 10 to 15 percent is pretty common..A generator aims for less droop..the less droop however the engine is more apt to hunt.
But just for easy figuring we will use 10 percent droop..An engine set for 3600 will not fully open the throttle until the engine is pulled down 10 percent..Now the engine speed is 3240 RPM..our new peak HP..Is at 3240
Peak torque on most of the engines is 2400 to 2800 RPM..As we lug the engine from our 3240 RPM our twisting force increases until we lug below our peak torque.
Now here is where it gets interesting.
We are accelerating snow from 0 mph to say 50 mph... It takes four times as much power to double our acceleration.
Therefore more work can actually be achieved in theory with a slower Impeller as long as you are not overloading the impeller itself.. A slower impeller passing the same weight of snow in the same amount of time uses less power.. It takes four times as much power to accelerate the snow twice as fast.. As we can see if we use a smaller engine we can slow the impeller a little to make up for the lack of power...Our throw suffers as a result however.
Back to snow going around the Impeller.. snow getting worked around by the impeller and slipping it past generates heat.. that heat is wasted energy.. although it may have have helped keep the RPM up...we would have been better off slowing a better sealed impeller at a reduced RPM handling less of the same snow twice in the impeller.
Force..when we double speed..we have four times the force(stored )..Snow traveling double the speed has four times the potential(Just think of stopping distance on a vehicle) when our snow is moving faster is has much more potential to keep the sticky snow that just passed before pushed out of the way.
This is why when people raise engine RPM they are seeing a major improvement in having less clogs.. although the engine RPM increase may be only 5 percent.





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