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View Full Version : is horse power over-rated?


mike lane lawn care
07-05-2006, 01:08 AM
ok, so i was wondering, how come an old garden tractor with 8HP have a large towing capacity, and a rear PTO, and my state-of-the-art broadmoor with 20HP is only rated to tow 500 lbs, and has no Rear PTo, and can't tow a grader? is there more to it that just HP, because i was going to put a snow blade on the broadmoor, as it seems heavy enough but i don't want to stress a machine that i use for mowing. so what is the deal with HP?

topsites
07-05-2006, 01:14 AM
Although I think we are on the same track, I always thought it was more like it's UNDER rated LOL. What I mean is, a 15hp Kohler has a lot of power but it sure don't got the strength of no 15 real horses lol.

But to answer the question, I think back in the days of steel chassis the frame was able to withstand more pull than the lightweight alloys in use today.

Lynden-Jeff
07-05-2006, 01:31 AM
I really debated the horsepower thing when I bought my ZTR. Ill tell ya I had my heart set on a 23-25 HP kawi and at the last minute the dealer talked me in to a 19. IMO I'm glad I went with the 19, better gas mileage, no problems with power (I cut a field that was a good 12-15 inches and it only bogged under extreme piles of clippings), and by law in Ontario I do not need a rops for anything under 20 HP. If I wanted real power I would go diesel!

Cheers
Jeff

TriCountyLawn
07-05-2006, 01:48 AM
IMO ,I dont think you can have enough HP on a mower. We mow in wet conditions ALOT and the extra HP goes a long way. When mulching you I dont think you could have enough.

Palmer'sLS
07-05-2006, 01:50 AM
well i think that these hp rated motors are a joke.....i was talkin to a mechanic at my dealer the other day, and he told me that the difference between the 19,21,23,25 hp kawis was just a simple carb. setting...(this was discussed on an earlier thread i believe), anyways...and im with topsites, there is no way my 19 kawi is givin me the power of 19 REAL horses

tomo
07-05-2006, 06:39 AM
hello, limiting factor for towing maybe 1/chassis 2/ drivetrain 3/engine hp or cooling 4/braking capabilities-------any or all of the above. Engine hp is measured in at least 3 different ways world wide.Then you have different catergories gross hp, intermitant hp , constant hp . After all this b/s you have marketing spin. It can get real confusing at times!!!! Eg if you compare diahatsu diesel .950cc claimed exmark 26.5/toro 27hp and kubota .902cc claimed 23hp on the same graphs there would be lucky to be 1hp diff, both in the 23-24 range under same test criteria.Referance from kub and diahatsu web sites. Do not beleive every thing you are told!! Finally you have different hp spec of the same engine,when hp is actually inreased eg cams carb etc does not typically happen but it is out there.Usally only for marketing purposes"my engine is 1 hp bigger than yours"Give me 1.1 ltrs 28hp kub in a toro ztr now we are cooking*** TOMO

Nosmo
07-05-2006, 06:56 AM
well i think that these hp rated motors are a joke.....i was talkin to a mechanic at my dealer the other day, and he told me that the difference between the 19,21,23,25 hp kawis was just a simple carb. setting...(this was discussed on an earlier thread i believe), anyways...and im with topsites, there is no way my 19 kawi is givin me the power of 19 REAL horses

I believe him -- according to Kawasaki's power curve chart
my 23 HP Kawasaki develops 22 HP at 3200 RPM. When set to 3650 RPM it develops 23 HP.

Nosmo

Richard Martin
07-05-2006, 09:34 AM
I believe him -- according to Kawasaki's power curve chart
my 23 HP Kawasaki develops 22 HP at 3200 RPM. When set to 3650 RPM it develops 23 HP.

And if you were to continue the curve up the scale the HP would continue to increase. The Kawi dyno chart only shows power where the engine is rated to run at, not maximum power.

The numbers everybody should be looking at are the torque figures. Horsepower and Torque are inseperable. You can't have one without the other but they do two different jobs.

Torque is torsional or twisting force. It is the force that propels the mower up a hill or turns the blades. The more torque you have the more weight you can pull up the hill or the thicker the grass you can cut.

Horsepower is how fast torque can pull the weight up the hill.

Liquidfast
07-05-2006, 10:12 AM
I took apart my mower once and found what I believe was a piece of a horseshoe. SO.....I know for sure and without a doubt that my mower has ONLY 1 horsepower :realmad: .... I paid for ALOT more than that!

Picky1
07-05-2006, 10:18 AM
My 22hp 60" cut Dixie Chopper bogs in tall Bahia. Would I go for more HP? You bet!

mulcahy mowing
07-05-2006, 10:18 AM
woooooo wait isn't the're a formula for hp? like it can lift 530 pounds 1 foot in 1 second or something like that? I know those numbers are wrong but something to that degree. Mike, your tractor should be find with a plow i have an 18hp that pushes huge piles of dirt and snow every year all year....

grassmanvt
07-05-2006, 10:25 AM
Hp is hp, there are no two ways about it. One of the reasons for all the increased power (quoting from an article I read a while back) is that the older machines had a lot more gear and reduction capabilities. With iron and shipping prices, and by reducing the ammount of pieces and parts, it has been more economicle to produce units with larger engines istead of a smaller unit and trhoing a lot of gearing at it. As far as towing etc, I have no doubt that they would and could do it but, these units are primarily used for mowing, so are designed to mow. If you want a compact tractor, thats what you have to buy.

mowtech
07-05-2006, 10:35 AM
well i think that these hp rated motors are a joke.....i was talkin to a mechanic at my dealer the other day, and he told me that the difference between the 19,21,23,25 hp kawis was just a simple carb. setting...(this was discussed on an earlier thread i believe), anyways...and im with topsites, there is no way my 19 kawi is givin me the power of 19 REAL horses


The 19 hp and 21 hp Kawi are not the same; however, the 21 thru 25 might appear to be as are the 26 and 27:

FH580 19.0 hp = 585 cc
FH641 21.0 hp = 675 cc
FH680 23.0 hp = 675 cc
FH721 25.0 hp = 675 cc
FH741 26.0 hp = 764 cc
FH770 27.0 hp = 764 cc

Carburetion can and does effect the power, but this may not be the only difference. These engines may have different heads and heavier internal components to take the increased power.

Engine manufacturers test and rate their engines in accordance with SAE J1349 which gives a gross horsepower in ideal conditions. Gross means that there is no muffler or air cleaner used during the test. Note that for carbureted gas engines the difference between gross horsepower and net horsepower can be significant; hence, you are correct--the 19 Kawi is not giving you "19 REAL horses".

topsites
07-05-2006, 12:12 PM
well i think that these hp rated motors are a joke.....i was talkin to a mechanic at my dealer the other day, and he told me that the difference between the 19,21,23,25 hp kawis was just a simple carb. setting...(this was discussed on an earlier thread i believe), anyways...and im with topsites, there is no way my 19 kawi is givin me the power of 19 REAL horses

LOL that's funny you say that, supposedly the difference between the 13hp and the 15hp Kohler is a simple baffle in the carb that when removed from the 13hp suddenly boosts the power to 15hp thou I'm not so sure, I mean I've never wanted to spend the money on a 13hp just to find out if it's true or not. As for actual performance in the field, I put a 13hp b & s on an older 52" Wb and it was fine, but yes you had to go a little slower in the really thick and tall stuff.

At the same rate, going down to smaller equipment, the bg-55 and the bg-65 handheld blowers are the same cc's... However, the bg-65 costs 30 dollars more while it boasts greater MPH thou the CFM stays the same, it appears to be a matter of taking the bg-55's round nozzled tip and replacing it with the flat nozzled tip of the bg-65 for 10 dollars...

Thus I think you really need to look at cc's, keep in mind the cc factor is only consistent between engines of the same manufacture.

To say the least, you gotta watch these guys lol, do your own research and think some before you fork the money over.

mike lane lawn care
07-05-2006, 12:58 PM
wow this was a huge response. thanks for the replies .

mike lane lawn care
07-05-2006, 12:59 PM
If you want a compact tractor, thats what you have to buy.
does anyone have the price for a john deere 2210 sub compact tractor?

mulcahy mowing
07-05-2006, 01:51 PM
not sure if thats the model i was looking at a fair a few weeks back they were about 11k

mike lane lawn care
07-05-2006, 09:52 PM
not sure if thats the model i was looking at a fair a few weeks back they were about 11k
it can't be right, because i know that the small 3000 series one only costs about 10k, i was thinking it would be about 8-9k as the 4wd diesel simplicity legacy XL can be had for 9k