Snow blower power ratings

The principle is pretty gaseous as well. In the real world, the old and new 350 cc engines will have about the same HP. Seen any snow blowers with Briggs or Tecumseh engines that call for premium gas lately? Ever?

Reply to
salty
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Hi, It is all matter of useful HP and useful torque. HP rating is often very misleading. If Peak HP occurs near top rpm it won't be good. I'd pay more attention to torque. I still remember what I was told when I was a kid. Torque is how big a stump an engine can pull, HP is how fast.

Reply to
Tony Hwang

This is the most useful of the information supplied so far. I am going to make note of the ft lbs/hp ratios as the foot pound rating is the most popular of the ratings around here. The displacement ratings are almost useless in my opinion.

Thank you.

Reply to
Worn Out Retread

This is perfectly true. Engines of the same displacement can vary greatly in power developed due to the ratio of diameter of piston to the length of stroke, valve configuration, exhaust tuning and other factors.

Reply to
Worn Out Retread

I had an eight horse power MTD blower and for most most jobs it was perfectly adequate. Now that I want a new blower, I don't want to buy a machine that has less power than the old one but the published specs are just plainly designed to confuse the buyer and there are very few web sites that do much to untangle the mess of misleading information.

If all you are doing is clearing 6 inches of snow off a driveway that is one thing but when the snow plough comes by and dumps a mess 2 feet deep and 6 feet up the drive, that small snow blower is just not going to get the job done without nearly blowing its guts out especially if the material to be cleared has had any great amount of salt added to it making the mess very dense and therefore heavy and difficult to move.

Reply to
Worn Out Retread

So that works out to be approximately 70% of the rated torque if rated in foot lbs. which would be easily calculated while browsing different models. Someone else gave some equivalents of torque and horse power and the figures pretty well agreed with what you have given.

Thanks

Reply to
Worn Out Retread

Thanks for the link. I have used it before but the formula that they gave had me somewhat baffled what is 10 over score 7? Is it 10 to the power of 7,

10 to the power of 1/7, 10 divided by 7? No explanation is given and I have not ever seen that way of writing a formula.
Reply to
Worn Out Retread

That is exactly what I have been doing and they have no accurate information in this regard. They could only offer guesses.

Reply to
Worn Out Retread

I guess that you are only going to look at your machine and not actually do some work with it. Work requires power and knowing what you have IS important.

Reply to
Worn Out Retread

That is the point of the question asked. I want to buy a machine of at least the same power as the old machine but the system of measurement has changed so that creates a problem that I have to solve before parting with my money.

Reply to
Worn Out Retread

Try this converter:

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Apparently 5 hp IS 9 million foot pounds per hour.

Reply to
Van Chocstraw

How will you know how much power it has? Surely not by the HP ratings on the engine.

Reply to
Ed Pawlowski

Lordy. Unless you are buying pro-grade gear, odds are it is gonna be an MTD anyway, no matter what brand name is stuck on it. The same size blower will have the same engine across all the house brands. Buy the size you need, and move on. Almost always, it will be adequate. The manufacturer has no percentage in giving themselves a bad reputation, so they match them up pretty well. Don't lose sleep over it- life is too short.

-- aem sends....

Reply to
aemeijers

You are blowing smoke. Because you don't know anything about engines. My numbers were a bit high. A 20HP Intek is 8.8:1. A 25 HP Kohler Command is 9:1, and the Briggs Animal runs 9.5, 9.7, or 10.0 :1 depending on class.

From Popular Hot Rod's tech pages:

Basics Increasing the CR produces an increase in output throughout the rpm range. It is also worth an increase in fuel economy. If a longer duration cam is installed, raising the CR at the same time can be worth even greater dividends than these two moves considered separately. When the CR is raised, peak combustion pressures are increased. As a rough rule of thumb, cylinder pressures are about 100 times what the CR is so, from a 10:1 engine, we would expect to see about 1,000 psi of peak combustion pressure.

Cylinder pressures and output will increase as the CR is raised, but what is less obvious is that the increase in compression also increases the engines thermal efficiency. Thermal efficiency is a measure of how effectively the engine converts heat into mechanical power. To appreciate this it is better to consider the engines expansion ratio (ER). This is the opposite side of the coin to the CR and describes what is occurring as the piston moves down on the power stroke rather than what happens as it moves up on the compression stroke.

Reply to
clare

Well you are wrong on both counts. I use a 24" rotary "push" mower to mow my lot all the time, and current lawn mowers are rpm limited to prevent tip speeds in excess of 19000 ft/minute - and in some cases

14000. It's the LAW in Noth America for all home use lawn mowers. Apparently SOME commercial units may excede the tip speed depending on other fastors that I am not aware of.

It IS because of this that lawn mower power ratings were changed. The engine is rated at a given HP at 3600 RPM - but the equipment does not allow it to run at that speed so the HP rating is no longer valid.

Reply to
clare

If a particular frame size is available with 3 engine options (which is normal) buy the middle one for normal use, the big one for heavy snow conditions, and the small one as an ornament. (or for light snow conditions)

My old 26 incher was available as a 5, 8, and 10 hp.

Mine was a 5 HP Tec Sno-King and was adequate for normal blowing, but stressed handling deep packed snow plough ridges. When I blew the 5 I put on an 8, which was the same block as the 5, so fit with absolutely no modifications.

Reply to
clare

You have the tools now. torqueXrpm/5252=HP The old engine was rated at 3600 RPM - universally. So your new engine torque X 3600 /5252 is the rating of old engine that is equivalent.

If it is an OHV engine it will usually have a broader power range, so will do MORE work than the old side valve equivalent, and on less fuel.

Reply to
clare

You must be talking pro-grade from an equipment dealer. None of the stores around here that are open evenings and weekends, offer any choices in engine sizes. I'd wager the price at an equipment dealer is a lot higher than at the big-box, as well. Of course, you are up in Canada- I suspect there may be more of a market for heavy-duty stuff up there. Around here in Baja Ontario (aka lower Michigan), anything over

15" shuts down the city for a day or two.

-- aem sends...

Reply to
aemeijers

But in THIS category of engines, that isn't generally a factor. Old and new Briggs utility engines of the same displacement will also have similar power characteristics.

You probably won't find a snowblower with a turbo option, and lowered suspension, either.

Reply to
salty

Bought my Ariens from a local mom & pop commercial tractor store for the same price as the big box stores.

Reply to
salty

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