hp ratings ?

GrayBeard · Feb 1, 2004

Thanks all.
Then another question may be; What percentage does a hydro diminish the engine hp ?
Is there a constant or are the various trannys so different, it's by mfg ?
After 30 yrs, I do know in the " large building construction industry" those engineers do a lot of "not specified" and usually cost millions to the customers or owners.
GrayBeard

JDgreen227 · Feb 1, 2004

Greybeard,

According to my JD brochure my 4210 delivers 23 pto hp with the Syncshift transmission and 22 pto hp with the Ehydro and the large frame 4610 delivers 37 and 35 pto hp using the same transmissions. I would think the majority of tractors with comparable gross hp to my JD (28) would lose about 1 pto hp to the hydro.

nomad · Feb 1, 2004

( engineers do a lot of "not specified" and usually cost millions to the customers or owners.)

If those engineers are an employee of a manufacturer (a person), then "that manufacturer" is responsible of all costs as he/she is commanding engineers. When making profits it's the profit of manufacturer, but when taking reponsibilities engineer should take? This isn't fair.

As for this question by JDGreen227,
( I like the way you describe it: "an implement MFG should give ONLY pto hp as an input to his implement". You may be able to answer my query: Suppose I have a 23 pto hp tractor and a 25 pto hp implement, will it damage the tractor if I hook them up? Or, suppose I hook up a 30 pto hp tractor to a 25 pto hp implement, would that damage the implement? )

This simple, but important question actually digs a bug in the engineering field badly. Good question. What's the critical HP to be chosen? Ps: One minute, coffee is boling;-0 Taking one cup and coming back. Such a question should be answered in a good simple technical language.

Renze · Feb 1, 2004

Over here in Europe, everything is counted in engine hp.

Even if your small tractor has enough drawbar hp, it doesn't mean that if one 30 drawbar hp tractor can pull the plough, the other tractor with 30 drawbar hp can too..

power is force x speed. Your lightweight little tractor may put out some good drawbar hp at 12 km/h, but that is combined with a low force.
A farm tractor of 30 hp, which might be twice as heavy, will put out this drawbar hp at 7 km/h and have a higher drag force. However, due to it's weight, it wont be able to put out the same drawbar hp at 12 km/h, like the lightweight can.

At our small farm in the netherlands, we use machinery with a 50 hp Zetor 5245, the machinery is advisable for 70 hp or some even 90 hp.
Mostly it isn't a problem, due to the relatively high drag force because of the 3100 kg weight and 4wd. It's just a matter of matching the right gear to the work.
Only in some situations, when the working quality will be decreased by a lower working speed, these advised hp requirements apply.

But in this case, you're working with a lightweight compact tractor which is NOT built for heavy pulling, so you might overstrain the axles and gearbox. But i think there are enough compacts that will stand up to these jobs without any problems. I mean, just compare a Kubota B7001 15 hp to another Kubota of the 3000 series (???) i think the B7001 is not built for heavy tillage, and CERTAINLY not comparable to the rear end of a 5245... /forums/images/graemlins/wink.gif

nomad · Feb 1, 2004

( Suppose I have a 23 pto hp tractor and a 25 pto hp implement, will it damage the tractor if I hook them up? Or, suppose I hook up a 30 pto hp tractor to a 25 pto hp implement, would that damage the implement? )

I'm back. After reading replies again, I see the poster Bird already answered this well, with a short practical answer by mentioning about HP ranges and saying that, say, HP of a gearbox of an implement are given by MFGs as maximum HP you should apply on that gearbox. So, not too much left to say. But I can still add a few things by asking a small question (especially for implement manufacturers rather than for the users); What critical/maximum HP should be chosen by a manufacturer of a gearboxed implement? Should it be more than tractor pto HP or less than tractor HP? I can imagine your answers "implement hp should be less than tractor hp" and yes, it's so, say, for example if the implement is a relatively cheaper item like tiller - But, what if it's a baler which 'sometimes' costs more than a tractor? As we know in the real field, most of tractors are old and not worth more than $20,000 while a new baler can cost even more than $30,000. Ps: I never used a baler.

Bird · Feb 1, 2004

( what if it's a baler which 'sometimes' costs more than a tractor? )

Yep, I spent a couple of summers pulling a $20k baler behind a $5k tractor. /forums/images/graemlins/laugh.gif Of course the baler was new and the tractor was 25 years old. /forums/images/graemlins/grin.gif

Egon · Feb 1, 2004

How quickly we forget SHEAR PINS.

Egon

nomad · Feb 1, 2004

( How quickly we forget SHEAR PINS.

Egon )

Yes, Egon. Good answer.
But how quickly all forget SHEAR PINS - I searched the forum and saw A LOT of posts in last 2 years asking about their frequenly-broken-shear-pins. We should accuse someones for these pins, who to accuse? I don't feel good when accusing the shear pins themselves

Buster57 · Feb 1, 2004

I accuse the gophers of breaking the shear pins! It seems like if I grind through enough gopher mounds, I always break a shear pin!
Regarding the parasitic loss of power associated with hydrostatic transmissions, this will vary from system to system. Also take into consideration that most of the CUT manufacturers are very conservative in assigning PTO HP to their units. I was told once that in addition to best engineering practices, there may be a tax reason for this as well. Why is this important? I use a First Choice RT10-66 on my L3010 that is rated at 24.5 PTO HP. This should be just on the edge of performance. I believe that the soil conditions and the conservative rating of PTO HP by Kubota are why I have no problems at all with the 66" rototiller used with my tractor.
Have fun!