Snow Blower Performance

[Industrial Toys]

Hi People;

I have a big problem and quite a disappointment. Over the years, I noticed that not all snowblowers are created equal. The best blower I ever owned was a Lucknow 6.5 foot behind a Universal 445 tractor. Nothing I owned since, has worked as well.

Recently, I bought a 7 foot Mckee SnowLander, double Auger blower, that was equipped with a 65 HP Wisconsin Engine. I don't know if McKee made this machine, but i don't think so. The
engine has a Rockford clutch, that is then belt driven (4 belts) where it is reduced and then to a smaller double roller gear and then to the input shaft of the blower with a larger gear.

I use this on the front of a Kubota R510 using a skid steer attach plate.

The problem is that the performance is miserable, as far as throwing distance. The clearance of the impeller is quite close, within half an inch. I thought about changing gear ratios to make the blower run faster, but got into some heavy stuff, and think that maybe I don't have the horse power.

The engine starts like a dream (even though I detest gas engines) but wonder if the engine might be weak. It doesn't appear to burn oil, but could this be, that the engine isn't producing 65 HP?

Does anyone out there have any real experience as to what makes a snow blower perform well? Can one do anything to improve the performance? Being able to blow snow a good distance, is a real asset, when doing large areas. Right now, the blower only blows twenty five feet or so.

Maybe a nitrous kit?

Thanks

 

[RFB]

25 feet is not poor performance, although further is better.

What I have found is that there are several factors in play with snowblower performance. One of those is the water content of the snow; very wet heavy snow blows "chunkier" and not as far as dry powder, but powder is also more widely dispersed than wet snow, which seems more uniform in its deposit area.

The prime consideration in my experience has been fan (not auger) characteristics: size of fan blades and speed.

When fan speed drops off, fan velocity and distance seem to suffer in direct proportion. As long as I maintain fan speed by keeping the pto at rated (540) speed, performance remains good. As tractor/blower feed speed increases, one reaches a "sweet" spot that feeds enough snow at the proper rate that allows proper fan speed and tractor movement, and resultant optimum throw.

 

[hdbikercouple]

there was a post awhile ago and 1/2 was way too much . they were saying about a dimes thickness. hope it helps i'm no expert.

 

[hdbikercouple]

there was a post awhile ago and 1/2 was way too much . they were saying about a dimes thickness. hope it helps i'm no expert.

 

[tessiers]

My blower has about 3/16" between fan and housing. It blows even wet snow 50'+, if I keep the RPM's up

 

[Industrial Toys]

I wonder if it is worth the effort to rebuild the impeller? I looked at another non-achiever snow blower of mine, a George White "Blizzard" 7 foot single auger, to inspect the fan clearance, and was surprised to find that the fan housing gets rather far away from the fan already some distance before the snow exits, so it made me wonder, just how critical distance is.

When I run this blower, on my JD 6200, I have the engine opened up wide, turbo going, and little performance here too.

My GF has someone do her snow, and he shows up in a 2WD JD, with the engine just above idle, moving snow a great distance.

I've got to find out, what gives!

 

[RFB]

I don't know if it would help, but something like this Snowblower Impeller Kit might be an easy way to close the gap.

 

[hwp]

There are two factors which affect the performance of a snowblower - discharge velocity and clearance between the impeller and the drum. To a point, the greater the discharge velocity, the further the throw. A discharage velocity of about 5000 feet per minute should give at least a fifty foot throw. A 20 inch diameter impeller turning at 1000 rpm will give a discharge velocity of about 5200 fpm.

The gap between the impeller and the drum affects the ability of the impeller to carry the snow to the point of discharge. The drums on most snowblowers are not round but slightly oval. The critical sweep is from bottom dead centre to the point of discharge 90 degrees later - the rest doesn't matter. When the gap between the impeller and drum in this part of the rotation becomes too large, performance suffers considerably. I was told by the owner of the shop that built my snowblower that the impeller should pick up a dime at BDC and carry it to the point of discharge. I follow his advice and rebuild the tips on the impeller of my snowblower when the tips get worn to this point - about every second season. When I rebuild them I strive for a clearance of 0.020". The result is the machine is back to peak performance.

You questioned whether or not you engine had enough power to run the snowblower - i would think so. The rule of thumb I have always heard is 5hp per foot of throat - you are well beyond that.

I hope this helps.

 

[Industrial Toys]

Good information. I understood the part about the fan cavity not being
round but oval, however, on my George White, from bottom dead centre,
is where the oval starts and the clearance becomes huge! A few inches.
This is what had me baffled!

But I really don't care about that snow blower, as I will get rid of it.

It's the other, self powered one, I would like to optimize. I could add those filler plates, but I would question the fact that there might be drag caused by the uneven impeller surface. Short of building an entirely new impeller, what can one do to extend the impeller blades, while still keeping it balanced?

 

[RFB]

hwp,

How do you rebuild the fan blades?

 

[hwp]

I use two or three passes of hard weld along the tip of each blade and then carefully grind them down to fit the drum. I check the fit with a feeler gauge. It takes a bit of time. The other thing to check is the balance of the impeller. It is sometimes necessary to add a spot of weld to the back of a blade and then grind it down as necessary to keep the impeller balanced.

 

[smfcpacfp]

The gap between the impeller and the drum affects the ability of the impeller to carry the snow to the point of discharge. The drums on most snowblowers are not round but slightly oval. The critical sweep is from bottom dead centre to the point of discharge 90 degrees later - the rest doesn't matter.

Just a minor point but wouldn't that be 180 degrees?

 

[Industrial Toys]

I thought about messing about with a mig welder and grinder.
Probably not a good idea for balance!

I would get someone to make me a whole new impeller,
if I knew for sure it would be a marked improvement!

 

[hwp]

Just a minor point but wouldn't that be 180 degrees?

No, the point of discharge is where the blade becomes horizontal and the wall of the drum is vertical opening into the exit passage . The snow always wants to move to the outer edge of the blades so at the point where the exit passage intersects with the drum the snow will move up the exit passage to the discharge chute.

On many snow blowers there is a restriction plate at the transition from the exit passage to the discharge chute. The larger the hole in that restriction plate, the better the snowblower will perform. Similarly, the lower the friction in the discharge chute the better the performance will be.

 

[RFB]

hwp,

Just thinking out loud, but instead of steel, what to do think of using a system of replaceable polyurethane edges on the fan blades (similar to the pu snow plow edges) so that when wear becomes "X" dimension, old edges off, new edges on (or even adjustable and moved back into correct tolerance).

 

[Industrial Toys]

I would really like to understand this. If one actually understands how things work, one is better and better in a position to tackle almost anything! Just being told something is as it is, isn't good enough for me!

If it is the centrifugal forces that cause the snow to be ejected, then why would clearance be such an issue. It's not like you want to build as perfect an air blower as possible and then just substitute snow for air.

To my way of thinking, fan diameter and speed would be the most critical parameters, and yet almost all rear mount blowers run at the same 540 RPM max, and yet some as I have noted, work really well, at much lower then
full PTO speed.

Does anybody know what other thread pertains to this subject?
Also just as a side note. How can one keep track of ones threads
anbd posts on this site?

Thanks

 

[RFB]

log in, and then click on "My home". you will go right to your "subscribed" threads.

 

[Industrial Toys]

How would one go about balancing the impeller?

 

[RFB]

I am willing to postulate that impeller balance is not very critical.

The mass of the impeller on my blower is fairly large (27 inch fan blades, 3/8 inch steel with cross-bracing), and PU edges would be very small added mass to that overall.

Also, the varying masses of snow load and consistency, (ice, slush, wet and dry snow) must be part of the design tolerance, so that balance must be a relative term.

 

[doxford jim]

Hi Guys,

I am replying to this thread even though the subject is two years old.

I have just picked up a good sound used Allied Farm King 73" snow blower. It is made of heavy gauge material and I think, would be considered a commercial unit.

When I saw it being used, it threw snow only 15ft maybe 20ft. I noticed that someone in the past, had built up the fan edges with rod (look to be hard surfacing material) - I assumed, to prevent wearing. I wasn't aware of the clearance factor and will now go down and check out the impeller clearance. Building up and grinding to achieve say 0.015 to 0.020" clearance could easily be achieved this way.

Thx for the tip - I might get it to pump the snow thirty feet or more if I am lucky. I am assuming it is made with the PTO 540rpm operating speed in mind. I can't see any harm in going faster to 740RPM (I have dual speed PTO), which should improve net performance if clearances are right.

I will post the results of my check and mods if any. I sure would like to get a real good performance. I think most owners are overly generous with their estimates of how far the snow gets thrown, without realizing it. Then newbies end up having unrealistic expectations of what to expect from their machines. Of course technique is another variable to consider.

Thx

Jim