Torque vs Horsepower

[Ursushorribilus]

I've been searching on the subject, and see that torque seems to be more important than horsepower for mowing. A few questions remaining...

1) What is the relationship between them?

2) Can machines with lower hp have more torque than those with higher hp?

3) What brands and models of mowers, specifiaclly the bigger walkbehinds, have the highest torque?

Being somewhat mechanically unimformed, inexperienced, and possibly incurably inept, I defer and depend on the mechanically inclined and engineers among you. Tony

 

[dishboy]

1. Torque is what sticks you into the seat of your car and horspower is what keeps you there.
2. Generally horsepower and torque curves are a result of a lot of variables including cam lift\duration, bore & stroke and head design. Most high horsepower engines sacrifice torque in the low and mid rpm's were a mower needs it. The same identical engine with less cam lift will usually have less hp and more torque. Some engines with a really good head design have both, and large displacement engines may have both.
3. What mowers have the highest torgue? I do not know this.

 

[dishboy]

I errored, the same engine with less cam duration[not lift] will usually have less hp and more torque.

 

[MudslinginFX4]

For a truck atleast... "Horsepower is what sells the car, torque is what gets it off the lot".

 

[olderthandirt]

Originally posted by ECM LAWN
For a truck atleast... "Horsepower is what sells the car, torque is what gets it off the lot".

"Horsepower is what sells the car, CASH is what gets it off the lot".

Mac

 

[Albemarle Lawn]

Horsepower is a mathematical calculation.

Torque and RPM's are the input, measurable data pieces, horsepower is just a computation.

Check out the Randy's Ring and Pinion website, they have some cool calculation tools:

http://www.ring-pinion.com/calculators/calculatorsind.html


BTW yes it is torque that is really important. In fact, many engines such as the Kawasaki 25 and Kohler 25 do not actually make a usable 25 Horsepower. The "horsepower" rated is a gross maximum output number. Continuous horsepower for the Kohler 25 is actually closer to 20.

Something with REAL power, like my JD 1600 wide area mower, can hold a continuous, honest-to-goodness 65 Horsepower, at 3000 RPM's (vs 3600 for gassers).

Big torque at low RPM's means your motor is making more horsepower at a lower RPM.

The real advantage comes in heavy, tall grass or on hills. With a torquey diesel your torque actually increases as RPM's drop, which means, realistically, RPM's wont drop much at all.

My Deere diesel is so strong that it will smoke a belt at half throttle before it will stall the engine if you suddenly find your mower deck in "the thick stuff."


KB

 

[MudslinginFX4]

HAHA, your right about that Mac.... and thats the worst part, the cash.

 

[dishboy]

Albemarle Lawn, well said!

Olderthandirt, I am LMAO!

Tom

 

[Ursushorribilus]

Thanks guys, I'm getting the drift, if not understanding the exact technical aspects...I'm going to become a "torque junkie" instead of horsepower.


Albemarle Lawn, that ring-pinion website is pretty slick, I'll be using their calculator.
I checked out the John Deere 1600 Turbo Wide Area Mower on their website, what a monster! At $50,699.00, their listed price, I'll be a few years getting one of those The applications for one of those must be for really large acreage! What is the fuel consumption for that beast? Tony

 

[Albemarle Lawn]

My fuel burn has been a consistent 1.1 gallons per hour at full power. For our municipal work where quality of cut is not as important, I set power at about 75% and then I'm at about .9 gallons per hour.

For comparison, all my ZTR mowers have either the Kawasaki 25 or the Kohler 27. They burn 2.2 gallons per hour.

So there you have it. Cut 60" at a time with a gasser and burn 2.2 gallons per hour.

Or, cut 11 feet at a time on LESS THAN HALF THE FUEL...

Plus, I'm running OFF ROAD diesel, so that drives the cost down even further versus gas.

One day last summer I really amused myself. On 7 gallons, I cut a 10-acre school, a 20 acre park, and a 9 acre farm. Total revenues = $2400 +/-, total fuel =$9 +/-

Of course, that was a busy day. Normally we cut $300 of grass for every gallon of fuel on the $50,000 Deere. Every time the tank gets topped off at least another $3000 flows into the coffers.

Here's the sweet part..."Big Green" is paid for!!!

Ken

BTW $50,000 +/- is before the options, such as canopy, turn-breaks, worklight, and a few others. Total replacement on mine is currently $53,900 and don't forget another $2500 for sales tax.
I get off on telling my customers it cost as much as their 2004 Mercedes E Class or their Ford Explorer, Toyota Camry, and Honda Accord COMBINED!