[RC20]

I wonder if I'm set for life. I just bought a 1966 8hp. Snow-Thro, have a Honda 621, and (for clean-up near my office, a small Toro single stage).

That questions is what got me to looking at the Yamaha at 22 years old though its rock solid still.


If I had not been able to get the fuel tank part some years back..... and it was not easy as they changed it and it took serious digging by the former dealer (they still maintain Yamaha contacts or did last time I got shear pins)



I do have neighbors that would assist me if the Yamaha broke down so I don't need an immediate backup.



But if it failed something I could not fix then I would have to replace it.

 

[RC20]

Sometime it pays to run some figures out.

I was looking for the best hp to width ratio and the Ariens 24 inch with a 369 cc engine would be that. That is a ..45 hp to width ratio (.3 is pretty good for most) kicker, 17 ft lbs torque (they don't list HP after all the hoopla)

The Yamaha YS-624-T has 15 ft lbs on the track machine and right at 17 ft lbs for the wheel machine.

Now, can anyone beat that in a 6 hp engine? And its down low torque wise at 2400.


No wonder they were such beast, punched way the heck above their HP as torque is what does the work.

 

[tdipaul]

Sometime it pays to run some figures out.

I was looking for the best hp to width ratio and the Ariens 24 inch with a 369 cc engine would be that. That is a ..45 hp to width ratio (.3 is pretty good for most) kicker, 17 ft lbs torque (they don't list HP after all the hoopla)

The Yamaha YS-624-T has 15 ft lbs on the track machine and right at 17 ft lbs for the wheel machine.

Now, can anyone beat that in a 6 hp engine? And its down low torque wise at 2400.


No wonder they were such beast, punched way the heck above their HP as torque is what does the work.

The figures have been run out here many times in the past.

Are you sure the Yamaha 171cc engine is putting out the same or more torque than say a 306cc Ariens AX engine is?

That would be quite a feat.

 

[RedOctobyr]

I was looking for the best hp to width ratio and the Ariens 24 inch with a 369 cc engine would be that. That is a ..45 hp to width ratio (.3 is pretty good for most) kicker, 17 ft lbs torque (they don't list HP after all the hoopla)

The Yamaha YS-624-T has 15 ft lbs on the track machine and right at 17 ft lbs for the wheel machine.

Now, can anyone beat that in a 6 hp engine? And its down low torque wise at 2400.

Do you have a link for those engine specs? It seems... unexpected that a 6hp, ~200cc engine would make more torque than a 369cc engine. A small engine can produce more power by spinning faster if it can maintain torque as the RPM climbs. But it's less common for a naturally-aspirated smaller engine to produce more torque than a significantly-larger one.

I found this for the 624, with 202cc, which lists 6ps (6hp) @ 4,000 RPM, which would be 7.9 ft-lbs at that RPM.

https://www.manualslib.com/manual/656501/Yamaha-Ys624t.html?page=24#manual

I'd be curious to see more details of the engine, if it's somehow putting out that much torque.

 

[ZAK77]

I'd like to nominate the Briggs powered Simplicity (Sno-away) / Allis Chalmers (Tracker 7 or 8) from late 60's / early 70's.

I believe I'm the only active member that has ever used one but if you're an old iron aficionado, grab one of these.

It was way ahead of it's time with it's controls...engage the handlebar lever for it to move (not stop).

They're pushed with a garden-tractor based slide-gear transmission and the locking differential allows you to turn on a dime with zero effort.

The updraft carb on the Briggs flatty takes a little getting used to when rebuilding (mainly stopping it from leaking past the emulsion tube seat/seal) but it always starts on an easy pull. Migrating to electronic ignition is super simple; simply bolt-on the external coil; it's not a points-saver like on the tecs & Kohler-K electronic ignition kits.

EDIT: with the external coil, you can also add a stator and upgrade the flywheel for power generation.

Briggs rebuild

Alice tackling Stella.

^^ I have some 15" x-tracs on order for her.

I'd have to agree since i have the Simplicity version of that blower and it is a beast. Well it may not be the biggest and baddest out there, it's still a heavy duty machine.

 

[RC20]

I will dig out the page and copy it.



I had to translate the toque, so unless I got it wrong


https://www.convertunits.com/from/kg-m/to/foot+pound

I did find that max torque was at 2800 rpm - certainly explains whey it lugs down and keep throwing so good - I did not think that kind of info would be in there. . 2.1 kg*m (I would have to look that up for ft lbs) - Wheel YS is 2.3, no idea why the difference.

Yahmah (old models) was a very long stroke engine.

 

[RedOctobyr]

2.3 kg-m *is* 16.6 ft-lb, from what I can see.

But even at only 2800 RPM, that torque would make 8.8 hp already, never mind as it sped up more towards the 4,000 RPM power spec that I saw for the 624 (6hp). So I guess something doesn't sound right. No way would you list the engine as 6hp if it was already making almost 9hp at a much lower RPM, unless your marketing department is very humble

If the engine performs well, that's what counts. But it seems like maybe I'm missing something, or specs for different engines got crossed, etc.

 

[RC20]

My Passat Diesel has a 134 hp engine and it gets 247 lbs of Torque.

And its flat torque, runs 1900 to 3500 (hp max peak is 4000)

I never got deep into the math on torque and hp, but clearly you can manipulate it and the dealer did not say it was 8 hp, just that it performed like it was (torque) - I don;t have the curves to see how flat it is or is not.

I have been to two sites for the conversion and they agree, it sure acts like it. I was into 24 inches of packed snow last night (first gear) and it just putted along and out it went. The chute was literally buried top to bottom and side to side.

Passat is not a speed demon off the line , but once its rolling, I can drop it a gear or two (semi automatic) and go up through 100 mph easily (my wife asked me how I was doing that during passes)

I can copy the data but its on page 7-2 of my shop manual that has a publication date of 1986.


It does not look to be a typo as the wheeled model is listed as 2.3 kg*m

 

[cranman]

I'd have to agree since i have the Simplicity version of that blower and it is a beast. Well it may not be the biggest and baddest out there, it's still a heavy duty machine.

I have an Allis Tracker 7 ( new condition from my FIL who died in the early 70's) and a Simplicity sno-Away 7 ( parts machine though it is operational)....they are really great machines.

 

[RedOctobyr]

Your diesel is probably a turbo. Which would have different characteristics than a naturally-aspirated small gas engine. Their torque and power curves would usually look rather different.

In ft-lbs and hp, for all engines:
power = (torque * RPM) / 5252

The info mentioned 2.3 kg*m, which is 16.6 ft-lbs, apparently at 2800 RPM.

So (16.6 ft-lbs * 2800 RPM) / 5252 = 8.85 hp

I'm trying to reconcile how, if a 6hp engine could make that torque at that RPM, why would it still be sold as a 6hp? It's at *least* a 9hp, and that would only be if the torque plummeted at >2800 RPM, making the peak-torque also the peak-power (you might expect it to end up producing something like 10+ hp). It would be interesting to see the service manual page(s), when you got a chance.

Please don't take any of this the wrong way, I'm not trying to sound insulting, or like I think you're making stuff up or anything. It just feels like there's a piece that's missing (or at least that I'm missing), because this set of specs seems quite high on torque (for a ~200cc 6hp engine), and is seemingly under-selling the engine's power, significantly.

Even reputable manufacturers aren't probably that likely to really hold back on specs (like 9hp) that they've actually earned! That would, admittedly, be maybe a welcome change from the companies who were just making up inflated power numbers

 

[RC20]

No offense taken, I am still trying to untangle it.

One aspect of it acting like a diesel is hp is at 4000 (though they listed max ops at 3800 so go figure)
As it slows down its dropping into the peak torque and that is what counts work wise.

For years I had heard about the old John Deer diesel Johnny Poppers when the engine was part of the tractor frame and they had two side by side (horizontal twin) cylinders firing fore and aft. I got to a local tractor plow weekend demo and damned if they did not do just what people had said, bogged down till you swear they were going to stall but they just grunted and kept going (no turbo back then- I am sure there are U tubes out there)

That is what the Yamaha sounds like. I did not even have it at max throttle for that packed snow (it was light to start with so it was not as dense as I have seen but when its been dense just max throttle and it still blows it)
While I worked mechanics for 30 some years and was pretty advanced in electrical and electronics (job title at the end was technician/ engineer) I just never got a feel for hp and torque and how it can be manipulated. I worked on some big iron early on, but we just fixed it.

Yamaha is a side valve engine and they are noted for torque (don't know what underlies that) but the data seems to line up.

The dealer sold hundreds into Valdez AK with their 300 inches of snow and that was over the Honda which cost less. I don't think they even carried the wheeled model, just the 6 and 8 hp tracked.

I would have gone with the Honda as it cost less and money was tough, but the hp in the 24 inch width I needed was too low and its chute was like 15 inches vs the 22 for the Yamaha. I had a roof worth shoveled off into the driveway out front and onto the back deck I needed to clear.

Never regretted the Yamaha both for the controls layout and its operation beat the daylights out of the 24 inch Honda (never ran a 28 Honda so don't know how those two compared)

They laughed at me when I tried to bargain, they had at least 10 in the warehouse they had just gotten in and they would sell them all before spring at the list price. Not sure that is not the best money I ever spent.
That picture is it last year, 22 years old and it looks almost new and still works the same way.

 

[RC20]

I think I am getting some idea. HP is calculated from torque, not toque from HP.



this article I think does a good job and I am still absorbing it. Its an interesting subject that is not intuitive to grasp. Like temperatures, those of us used to Deg F have a "feel" for it and not the same with Deg C until its converted into F.



Horsepower vs Torque | The Fundamentals of Horsepower & Torque



So hp has to be derived from toque as I understand it, you cant work it the other way. Good to get challenged and made to work on it.

 

[RedOctobyr]

It may be more common to measure torque, and then calculate horsepower. But regardless of which one you're measuring, from one, if you know RPM, you can calculate the other. It's a fixed relationship between them.

 

[Honda1132]

Vohl -a bit big for a driveway but I remember these being used to widen roads when I was younger. Manufactured in Quebec.

Vohl Snow Blower |

 

[tabora]

The Vohl may be fast, but how about these...

 

[RC20]

It may be more common to measure torque, and then calculate horsepower. But regardless of which one you're measuring, from one, if you know RPM, you can calculate the other. It's a fixed relationship between them.

So that explains why the Passat has 247 ft lobs of torque from 1900 to 3500 rpm.



Got it, close to 2000 rpm difference and no toque change.

 

[RedOctobyr]

Sorry if I misunderstood, but the formula relationship between torque and hp doesn't necessarily have much to do with why your Passat has a flat torque curve. That's due to how they designed the engine, from the fact that it has a turbo that comes on at low RPM, etc.

The formula just determines the shape of the power curve (on the dynamometer plot) vs the torque curve. Take the torque value at any RPM, multiply by the RPM, divide it by 5252, and there's your power.

This page lists a dynamometer plot for a Passat diesel engine, showing stock values in red, and with their engine-control software modifications in green.
https://kermatdi.com/i-1102-new-q-pro-tdi-flash-tuning-for-2015-and-2016-jetta-golf-beetle-passat-sportwagen.html

The light red line is stock torque, dark red is stock power. The torque line is pretty flat, but it's not totally-flat. Otherwise, if you were still making the max 247 ft-lbs of torque at 3500 RPM, you'd be making 165 hp, not 134.

But the graph helps show that relationship between torque and power. One scales with the other. The shape of the torque curve is a result of the engine type and design. But the power curve will always have a direct relation to the torque curve, since the power is calculated from the torque. When the torque curve shows a bump, for instance, the power curve will also have a bump.

 

[tdipaul]

Do you have a link for those engine specs? It seems... unexpected that a 6hp, ~200cc engine would make more torque than a 369cc engine. A small engine can produce more power by spinning faster if it can maintain torque as the RPM climbs. But it's less common for a naturally-aspirated smaller engine to produce more torque than a significantly-larger one.

I found this for the 624, with 202cc, which lists 6ps (6hp) @ 4,000 RPM, which would be 7.9 ft-lbs at that RPM.

https://www.manualslib.com/manual/656501/Yamaha-Ys624t.html?page=24#manual

I'd be curious to see more details of the engine, if it's somehow putting out that much torque.

 

[tabora]

...

But note that the torque peak is way down at 2400RPM, not at 3600RPM where you actually run the engine for blowing snow. Wonder what it's down to at that speed?

 

[RC20]

tdiPaul shows the new Yamaha engine, not the old one. Which is cool, I was wondering.



No curves for the old one, but the reason torque is desirable down low is as the engine slows down from its MAP hp, it dropping into where it does the most work (torque).



RedOctobyer shows a torque curve for a 2015 Diesel not the flat toque 2005 Passat. He just can't accept that you can not derive the highly nebulous HP (horses, really) back to Torque. Per the experts it does not work that way.



Of course the below picture is a fabrication (its not a diesel by the way).