# Impeller speed



## bcjm (May 29, 2015)

I have a Ariens 1032 I repowered with a 13hp Honda GX390 few years ago. It did not throw snow as far as I was hoping for. I bought a Ariens ST824 this year to use instead. The 824 throws the snow pretty well. I am happy how it performed. 

I had some free time today so I took a look the 1032. First thing I did was to compare the rpm of the impellers. I used a cheap laser rpm meter from Amazon. Put a strip of the reflection tape in the impeller and measured both machines. The 824 measured 580 rpm and the 1032 measured 850 rpm. This is the first time I use the meter. I had a hard time get a consistent reading initially until I used a bigger strip of the reflection tape. 

Does anyone know how fast the impeller suppose to spin?

I also measured the rpm of the Honda crankshaft using the aluminum duct tape instead of the reflection tape. It got a stable reading of 3200 rpm. The duct tape is much cheaper than the reflection tape. 

I think the problem is the tension of the belt. It is kind of loose. The impeller rpm must be much slower under load. Does anyone know a good way to test the snowblower without snow?


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## Blackfin (Jan 25, 2016)

bcjm said:


> I have a Ariens 1032 I repowered with a 13hp Honda GX390 few years ago. It did not throw snow as far as I was hoping for. I bought a Ariens ST824 this year to use instead. The 824 throws the snow pretty well. I am happy how it performed.
> 
> I had some free time today so I took a look the 1032. First thing I did was to compare the rpm of the impellers. I used a cheap laser rpm meter from Amazon. Put a strip of the reflection tape in the impeller and measured both machines. The 824 measured 580 rpm and the 1032 measured 850 rpm. This is the first time I use the meter. I had a hard time get a consistent reading initially until I used a bigger strip of the reflection tape.
> 
> Does anyone know how fast the impeller suppose to spin?


For the 1032, using some googling and some assuming, it looks like the auger pulley comes in at ~9.5" diameter and the crank pulley (for the auger shaft) at around 2.75" (assuming the re-power preserved the original crank pulley size.) Assuming the pitch diameter for both pulleys tracks, the drive ratio is 3.45:1. With a 3200RPM crank speed you'd see ~926 RPM at the impeller. Lots of assumptions, guess and variables here though.

How's the belt? You think it's kind of loose. Did you keep the original pulley on the crank or did you go down a size (e.g. 2.5")? A smaller pulley would account for the reduced auger RPM from expected (850 vs 926) and it would also account for the looser pulley if you stayed with the OE belt.

850 is pretty good impeller speed. If it's not throwing well and it's also not eating belts (as may happen to a too-loose belt) you might look into the gap between the impeller and the housing which can be 1/2" or more. Impeller kits can do wonders to close that gap and improve the performance of the impeller.


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## bcjm (May 29, 2015)

I used the original pulley on the crank so the impeller should maintain the original speed. The gap between the impeller and the housing is about the same as the 824. I say bigger than 1/4 and less than 1/2. If everything else are the same and The impeller spins faster than the 824, I assume it should throw the snow further. 

I had to change the belt length since the crank is higher. I might have to get a belt just a bit shorter since it is out of the adjustment.


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## nwcove (Mar 2, 2015)

are both impellers the same diameter ? ( impeller tip speed )


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## RedOctobyr (Mar 2, 2014)

Looking at the Ariens service manual I had for my ST824, the specs listing include the ST1032. I'm looking at model 924084. 

It lists an engine RPM of 3600, impeller RPM of 1100, and auger RPM of 110. All the machines in the specs section list these same impeller/auger speeds, including the ST824. 

Given your engine RPM of 3200 instead of 3600, that should scale down to an impeller RPM of 980 RPM. So something doesn't sound right, especially on the ST824. Maybe the tach is reading incorrectly? If the belt was actually slipping that much, with no load on it, it would have to be REALLY loose, and I'd expect you might hear it. 

With the engine off (!) and the auger engaged, can you turn the impeller by hand without the crankshaft turning? That would give a sense of how much torque the belt is transferring. 

To be honest, if the engine RPMs are known, and the pulleys are stock, then I'd assume any grossly-unexpected impeller RPM readings are more likely to be measurement errors, vs things truly turning at maybe half of the expected RPM. Especially if you were having trouble getting steady readings. And in particular if the belt is transferring decent torque, given that you currently don't have a load on the impeller, so there is very little reason for it to be running slowly/slipping. 

The service manual I'm looking at is 00040600. I'd look up your machine on the Ariens manuals website to get your service manual: 
Ariens Application

(You might be able to get a cheaper source for reflective tape by cutting up an adhesive-backed reflective sticker? Like the letters/numbers stickers sold at home improvement stores for your mailbox, etc)


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## Town (Jan 31, 2015)

The current model Ariens engines are set for 3,600 rpm +/- 100 rpm and the resulting impeller speed is 1,010 rpm. The SHO has same engine speed and 1,083 rpm for impeller due to larger crank pulleys. So your engines seem to be running slow and the impellers seem very slow at 540 and 850 rpm. 

My engine is running at 3,500 rpm and the impeller at 1040 rpm. When I get a chance I will increase the engine speed. 

Good luck.


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## YSHSfan (Jun 25, 2014)

If the impeller/auger ratio is 10 to 1, it would be much easier to take the speed of the augers and multiply it x 10 to get the most accurate impeller speed.

Are the impeller shear pins still there, as they may be broken and the impeller might be tight enough to spin "normally" without a load, but it may be "slipping" under load.

Just a thought..


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## YSHSfan (Jun 25, 2014)

The GX390 engine should be running at 3500rpm, at least that applies to the GX390 engines installed on the HS1332 and HSS1332 (if I am not mistaken :facepalm_zpsdj194qh)


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## bcjm (May 29, 2015)

My ST824 is model 924082. My 1032 is model 924029.


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## BTodd (Feb 9, 2016)

The estimates of the impeller speed seem about right on paper, but there are just too many variables when comparing two different machines. Consider the impeller's gap, diameter, and fan area, and even how much snow it is trying to move. 

I had a Troybilt 7524 that would throw more snow when it was loaded up (like across the road into the neighbors driveway). If there was only a few inches, it would barely toss it a few feet.


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## bcjm (May 29, 2015)

It seems that the fan speed should be around 1000 rpm based on manual. I will increase the engine rpm the obtains the desired fan speed. 

I need to double check the fan rpm of my 824. Under 600 seems low.


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## Zedhead (Jan 1, 2016)

Do the impeller mod, and the 1032 will throw like a champ. The HM100 on my 1032 is running a little slower than 3600 RPM, and it throws snow over 40'


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## Shryp (Jan 1, 2011)

It might be easier to get one of those tachs that reads off the spark plug wires.

Remember impeller rpm = engine rpm x engine pulley diameter / impeller pulley diameter.

3600 x 3 / 9 = 1200 rpm.

Most older machines had around 1000-1100 for the impeller and a lot of newer ones are probably around 1200-1300.


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## bcjm (May 29, 2015)

If it throws snow over 25ft without modification after I tighten the belt and increase the engine RMP I will be happy. Drilling the paddles to add a kit seems a lot work.


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## 43128 (Feb 14, 2014)

on all the honda and clone engines I have worked with to increase the engine speed you back out the screw under the throttle lever until you achieve the desired rpm. the screw is spring loaded


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## bcjm (May 29, 2015)

It is not so easy to measure the fan rmp since the laser from the meter have to point to the reflection tap at a 90 degree angle. I did this from the chute pointing down. I was worry I am going to lose few fingers. 

I may have to measure the auger shaft rpm then x10 like someone suggested. Are all Ariens models have a 1:10 ratio between the auger and the fan?


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## 43128 (Feb 14, 2014)

you can see how the screw controls how far you can move the throttle lever in this picture. this is a honda gx390 on a landa powerwasher


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## bcjm (May 29, 2015)

Thank you for the photos.


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## RedOctobyr (Mar 2, 2014)

bcjm said:


> It is not so easy to measure the fan rmp since the laser from the meter have to point to the reflection tap at a 90 degree angle. I did this from the chute pointing down. I was worry I am going to lose few fingers.
> 
> 
> 
> ...


Look up the service manual for your machine, based on model # and serial #, and check the specs table to get your ratio. 

Or count how many times you need to turn the impeller to get 1 full turn of the augers.


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## Blackfin (Jan 25, 2016)

43128 said:


> View attachment 79113
> 
> 
> View attachment 79121
> ...


As an aside, wow, that is one rusty assemblage of parts.

Will be spritzing some Rustcheck on the similar parts of my R210III before putting it into service as a slow blower prime mover.


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## 43128 (Feb 14, 2014)

Blackfin said:


> As an aside, wow, that is one rusty assemblage of parts.
> 
> Will be spritzing some Rustcheck on the similar parts of my R210III before putting it into service as a slow blower prime mover.


yeah, it was sitting outside for about 2 years when i bought it for 50 bucks. also a lot of the rust is from all the soaps/chemical based degreasers. it still starts up on the first pull and runs like a champ though


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## bcjm (May 29, 2015)

The manual specs indicates that the engine is 3600 rpm, the fan is 1080 rpm. It does not have an auger speed. I assume it will be 1/10th of 1080.


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## Spectrum (Jan 6, 2013)

bcjm said:


> The manual specs indicates that the engine is 3600 rpm, the fan is 1080 rpm. It does not have an auger speed. I assume it will be 1/10th of 1080.


You're in the ball park. If the parts list calls out the number of teeth on the worm wheel you'll have a clue. 

Gilson oil bath drives have 21 tooth worm wheels with double helix worms for a 10.5:1 ratio

Pete


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## Zedhead (Jan 1, 2016)

bcjm said:


> If it throws snow over 25ft without modification after I tighten the belt and increase the engine RMP I will be happy. Drilling the paddles to add a kit seems a lot work.



It's not bad to do. Best thing I've ever done to my machines. I did my 1972 Ariens 832 and it turned it into a different beast. Before, it would only throw around 10 feet on a good day. It'll throw over 30 now. I was lucky to get it to throw heavy wet snow 8', now it throws it 15-20 feet.

One thing you don't want to do is over rev the engine. If you don't have an accurate tach, leave the set screw alone.


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## bcjm (May 29, 2015)

Do people take the auger out of the housing to drill or drill from the chute?


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## 43128 (Feb 14, 2014)

it takes me about 15 minute per fan to install the paddles


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## skutflut (Oct 16, 2015)

bcjm said:


> Do people take the auger out of the housing to drill or drill from the chute?


That would depend if you can reach the blades from the chute. You probably need a long drill bit to get them from the chute, but that would be easy enough to find. If you make a jig out of wood, and clamp it to the impeller blade as a guide, then all the holes will end up in the same places on all the blades. You also need to wedge a chunk of wood into the impeller thru the augers to hold things still while you work. 

Wear work gloves, or bring band-aids.

Removing the augers and impeller makes it into a much bigger job, and its probably cold unless you have a nice heated space to work in. 

On the other hand, if you need to replace auger or impeller bearings/bushings anyway, then removing everything would make the drilling process easier. You would still probably be better off attaching the paddles with the impeller installed however, to get the fit right.


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## Zedhead (Jan 1, 2016)

Gotta remember, the 1032 has a 6 blade impeller.


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## bcjm (May 29, 2015)

I think I have only 4 blades. Maybe the 36" bucket has 6 blades.


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## YSHSfan (Jun 25, 2014)

bcjm said:


> I think I have only 4 blades. Maybe the 36" bucket has 6 blades.


If it is a 924 series it likely has a 6 blade impeller.
I have 2 ST1032, a complete auger housing from an ST1032, an ST1236 and an ST828 and they all have a 14" 6 blade impeller (all 924 series).


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## bcjm (May 29, 2015)

It is model 924029. The parts diagram shows 4 blades. I will check when I go home.


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## skutflut (Oct 16, 2015)

Zedhead said:


> Gotta remember, the 1032 has a 6 blade impeller.


If its a 6 blade, then I doubt you could get it through the chute, too many dam blades in the way.


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## Zedhead (Jan 1, 2016)

My 924050 has a 6 blade impeller fan. It was NP drilling the blades with a 6" long 1/4" drill bit.


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## YSHSfan (Jun 25, 2014)

bcjm said:


> It is model 924029. The parts diagram shows 4 blades. I will check when I go home.


Maybe early 924 blowers had 4 blade impellers along with short chutes.
Is the impeller 14" or 12" ?
With a long 1/4" drill bit you can do all the drilling that is needed.
What you also have to do is make a mark with a center punch for the drill bit to start and somehow lock the impeller (usually with a 2X4) so that it does not move when you are drilling.


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## RAYAR (Mar 7, 2015)

In your post showing the engine drive pulley with the belts, you notice the drive belt is flush with the top of the pulley, the way it should be. On the other hand, the blower belt is worn quite a bit as it is low in the drive pulley effectively decreasing the driven pulley diameter which in turn decreases the RPM of the impeller pulley. It would also likely be getting loose unless you have made an adjustment to regain the lost belt tension when engaged.


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## bcjm (May 29, 2015)

Do belts come with different shape of V? My belt is pretty new. I used only one time after the conversion. 

I did measure the 824 auger speed the other day. I put the reflection tape on the auger shaft bolt On the side of the bucket. I got consistent reading of 99 -100 rpm. So the fan speed should be about 10 times that rpm. The 824 is running correctly. I put the reflection tape on the auger shaft to measure the rpm originally. I think the auger cut off the laser when rotating caused the meter can't read the signal correctly.


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## Bob Cat (Jul 15, 2014)

Make sure you use reflective tape and don't have any other marker on the shaft that could interfere with your reading. I have that same tach and it is steady and accurate.


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## Mike C. (Jan 28, 2016)

Probably a foolish question Shryp,but in your impeller speed equation, are those pulley diameters measured as O.D. or groove diameters.Sorry if I'm splitting hairs a tad,but I'm curious.Thanks.


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## bcjm (May 29, 2015)

Are you talking about this? 
3600 x 3 / 9 = 1200 rpm

3/9 just a ration. It does not matter where you measure. It could be OD or groove.


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## Mike C. (Jan 28, 2016)

bcjm said:


> Are you talking about this?
> 3600 x 3 / 9 = 1200 rpm
> 
> 3/9 just a ration. It does not matter where you measure. It could be OD or groove.


 Yes,you're right.As long as you measure both pulleys the same way it makes no difference the ratio is the same.Thanks,I appreciate you clearing the trees so I can the forest.


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## AL- (Oct 27, 2014)

Your 1032, looking at the photo I think is an older machine than the ST824. I have an 824 that looks like the 1032 (handle bars & control levers and short chute are similar) It has about 1/8" to 1/4" clearance around the impeller and does not throw snow all that well. The short chute might be a drawback as the short bend cuts the flow. I thought the ST824 is little newer machine and maybe has a longer chute. Awhile back someone here on the forum installed a longer chute and that improved performance. If memory serves I thought he bolted the chute from a St824 onto his older 824.


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## bcjm (May 29, 2015)

Yes, the 1032 is older model than the ST824. I noticed the impeller gap of 1032 is wider also. I think it is more than 1/4". I tightened the belt a little more but it still did not throw snow well. I think a impeller mod is inevitable.


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## CDASnowblower (Jan 12, 2020)

I cannot emphasis enough to you the incredible benefits that go with installing the simple "impeller modification"! I owned a ranch in Colorado and dealt with an enormous amount of snow. I had a very expensive snow blower and when the snow was the least bit wet (or heavy) the machine would bog down and the throwing distance of the snow was terrible, plus I had to deal with endless clogging. Then I saw a simple little video on You Tube about this improvement and it was a real game changer. I don't know how I have ever lived with any snowblower before doing this mod! In fact, 4 years ago after sell the ranch I moved out of state (still in heavy snow country) and treated myself to a new $1,800 Toro Powermax. Fantastic machine by the way but there was still a very small gap of between 1/8" and 3/16" at the impeller... and I STILL FIXED IT WITH THIS MOD because the wet or slushy snow still slowed things down too much. My machine will now shoot that sloppy mess across the yard. My next door neighbor (who you can't tell anything to that might actually help him because he didn't think of it) has a full HALF inch gap on his John Deere snow blower which is mounted to a $20,000 garden tractor. This thing pisses snow out so poorly that it is just painful to watch. I tried to tell him about this mod and that I would be happy to do it for him as a good neighbor and he simply responded with this, "If it was a good idea I'm sure the people at John Deere would have already thought of it". Oh well. Check it out and give it some consideration. Just don't do it with self-tapping bolts. Use stainless steel 1/4" through-bolts with locking (nylock) nuts and fender washers. This way it will last forever. You can thank me later


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