Outdoor Power Equipment (Lawn Mowers, Snow Blowers, Chain Saws and more) Discussions

Does anyone know why the new engines does not have HP raing anymore?  It only indicates how many CC.

http://www.washingtonpost.com/wp-dyn/content/article/2008/02/15/AR2008021501732.html

Stainless answered it. For why it really doesn't matter, take a look at this thread: http://www.abbysguide.com/ope/discussions/60460-0-1.html

Here is a formula I have found on the net to calculate horsepower...feet/lbs. torque x rpm divided by 5252...this will give you the horsepower for your snowblower...ex: 21feet/lbs. of torque x 3600 rpm divided by 5252 gives me 14.39 horsepower...This is what comes up for my Ariens Pro 28 snowblower with a 420 cc Briggs engine...

It sounds like they are going the same way the Auto industry went. They used to rate by cu./in & HP, now it's just Liters.

The reason why they switched to Litres is simply because of the metric system in Canada and to be compatible with the rest of the World. In the USA it is still the imperial inch system. Cubic Inch is for the Imperial system and Litres or cubic metres for metric. This defines the displacement of the engine. Horsepower is part of the inch system and it still used today in the auto industry combined with other metric values/specifications. It gets kind of complicated for someone who doesn't know both systems...ex: my son goes to a Canadian High School and they are teaching him only the Metric system and no Imperial inch system at all....However, they still speak about Horsepower which is part of the inch system. Instead they should be speaking about Kilowatt power to be more accurate and standard with the Metric system. Actually, they should be teaching both systems as it is used daily in Canada. Especially in the manufacturing world everything is converted to the Inch system before processing. I personnally prefer the Inch system over Metric as it is the system of the Universe and not made by mankind...

The Marketing and sales people Lie about the Horsepower, and use it to sell whatever they have on hand.  So the actual(usually in Cibic Centimeters CC, for short) Displacement is all you can get which still doesn't tell you how powerful any given engine is.  If Consumer Reports would just accurately and objectively measure and publish the horsepower of the engines on the machines they test, they'd force the manufacturers to publish actual and not fictitious Horsepoer meausrements.   This is just one issue, and why buying power equipment is an exercise in evaluating what the seller doesn't want you to know.  If you get actual accurate HP numbers, then try getting the size of the friction whaeel and drive plate that make the snowblower move.  Good luck finding out that speciafication, or even just how much the machine weighs.  Like I said they don't want you to know . . . . A Lot !

Knowing just the Cibic Centimeters is almost useless to me.   A two liters race engine is complete different from a 2 liters engine used on the street.  I never pay too much attention on the actual size but the HP rating when buying a car.  

The problem with rating by displacement is that it is just the volume of displacement. There are many factors that effect the actual power such as Exhaust, Carb., valve & Ign. timing. Granted there are not too many options available to hop up the power of small engines like there are in the automotive sector so you are pretty much stuck with what you get.

I'm fine with them rating by torque, but not if they're just going to continue to make up numbers. The upside to listing displacement is that you really can't fudge it. Cylinder diameter is easy to measure, as is stroke. It at least provides one method to compare "theoretical" performance. But it would be nice to show some measure of the engine's actual performance. You could build a 400cc engine that makes 2 hp if you wanted to.

It is funny, though. I think of temperature in F, distances in inches/miles, etc. But I consider engine displacement in cc's/liters, not cubic inches.

They can't make up torque numbers, and if you think they are, you can measure it yourself. It's the ONLY useful measurement of power for small engines.

Bill_H wrote:
How would you go about measuring torque? It would seem no easier to measure, and therefore no harder to fake, than power. If you have the ability to measure the torque, then getting the RPM's should be easy (tachometers are readily available). And at that point determining the horsepower is a quick calculation away. But measuring the torque does not seem trivial to me, using anything that a "normal" person would have access to.

To New_Yorker's earlier point, sure, it would be cool if Consumer Reports measured the torque of each engine. But they certainly don't put every car on a dynamometer to measure its power (nor, for that matter, do performance-oriented magazines, when testing non-modified cars). And for a car you can just strap the whole car onto the machine, and go (oversimplifying a bit, of course). For OPE, you would likely need to remove the engine from each machine to try and test it. That's not going to happen anytime soon. So it would appear that we're stuck going by what the manufacturers tell us.

Bill_H wrote:
And of course, if we're being technical, torque isn't a measure of power at all (j/k , I know what you mean)

I want to know how much "power" the augers have in terms of ability to hold it's rotation speed Under extreme conditions. Including the impeler. Remember, belts clutches etc. they all " eat" power! Including non hydro drive

JoelKlein wrote:

Yep, there's a lot more to performance than engine power.  Centrifugal (rotating) mass can eat power, but can also allow the machine to lug through bits of heavy stuff better (the flywheel effect).  As for snowblowers, there's impeller design/speed, as well as other factors determining ultimate performance.

Things like valve timing and overlap, bore/stroke ratio, flywheel specs, etc. will determine the engine's internal lugging ability, whereas external components can determine overall lugging ability.

The old Allis Chalmers WD45 tractors were quite popular in their day (~60 years ago).  The diesel model utilized a 230c.i. (3.8L) six-cylinder engine that was tested at 30hp at the drawbar, 259lb-ft torque at 1169rpm - the gasoline model was a 226c.i. four-cylinder tested at 38hp and 288lb-ft torque at 847rpm. The HP numbers don't look impressive for the engine size, but the engines had fantastic lugging ability which was important when using ground-engaging attachments.  My brother still uses one on the farm.