Oil & Fuel Diesel Tractor HP vs. ATV or Car

[VTSasquatch]

I am new to this board and am looking to buy a 20 to 30 hp utility tractor. My question is this: Is the horsepower rating of a diesel tractor comparable to other vehicles like a car or atv? For example, I have a 700 cc atv that supposedly puts out 56 hp. Does that mean it has a more powerful engine than a 30 hp tractor?

I can't understand how a bulldozer can be 30 hp and a ford focus can be 250+ hp.

Could someone please explain this to me. I don't want to buy a 20-30 hp tractor and find it has less pulling power than my atv. Thanks.

 

[GilaSlim]

First off, you should read this Wikipedia definition of horsepower, and the many ways in which it is measured. Horsepower - Wikipedia, the free encyclopedia

The horsepower rating most often published for tractors is PTO horsepower, measured from the PTO shaft. For farm tractors, Drawbar horsepower is often listed. The engine's gross and net horsepower ratings are seldom published. All four different ratings are measured by different methods.

Finally, a 30 hp diesel tractor is going to have a lot more "pulling power" than an ATV or passenger car.

 

[leftturn7m]

It is all in the transmission and differential gearing. The Volkswagon bug got about 65 horsepower but could (mostly) run 70 mph while a 65 horsepower tractor couldn't touch that...it is due to the gearing.

 

[VTSasquatch]

Left, if it is all about gearing, does that mean that if you put an atv engine (56 hp) into a tractor or bulldozer it would have the same power as a 56 hp tractor/dozer? Or is it a separate unit that is measured.

I did read wikipedia but I didnt really understand. It looks like hp is a measure of output over time so a higher rpm engine with less torch can put out more hp. I dont understand it.

 

[SkyPup]

My racing go kart with its 125cc two stroke single cylinder gasoline engine puts out 35 horsepower at 13,500 rpms and only weighs 200 pounds, top end is over 100 miles per hour.

My Kubota L-39 Tractor-Loader-Backhoe has a three cylinder diesel engine that puts out 39 horsepower at 2,200 rpms any only weighs 7,000 pounds, top end is about 12 miles per hour.

Putting the tractor diesel engine in the go kart will not make it go any faster, and putting the go kart engine in the tractor will not make it go any faster either....

 

[leftturn7m]

Left, if it is all about gearing, does that mean that if you put an atv engine (56 hp) into a tractor or bulldozer it would have the same power as a 56 hp tractor/dozer? Or is it a separate unit that is measured.

I did read wikipedia but I didnt really understand. It looks like hp is a measure of output over time so a higher rpm engine with less torch can put out more hp. I dont understand it.

Think about a car with a manual transmission.....(this is a bit outside and more representative of torque but works)...If you take off in first gear you can get to 15 mph MUCH quicker and could pull much more weight as opposed to taking off in fifth gear. Sort of like rear end ratios. In my race car, we run a 6.14:1 rear end gear. That means the crankshaft turns 6.14 revolutions to 1 rear tire rotation. Again, more power used but less top speed. About 7000 rpm but only about 90 mph.

I am rambling and I hope I haven't confused.

 

[MossRoad]

Here is a link to one of my favorite explanation of Horse Power and Torque. Read it and enjoy a good laugh, too.

http://www.vettenet.org/torquehp.html

 

[Soundguy]

Also keep in mind that a tractors rated hp can be maintained for long periods of time.. IE.. hours or days of running at max rated hp and rpm.

Take yer atv, tach it out to max rated rpm under heavy load.. I bet it's lifespan will be measured in units -LESS- than hours..

Take that same ATV and hitch it to a 4000# rolling weight... it will spin tires .. take a decent tractor hitched to that weight.. it will likely pull it if it has enough weight.. ( IE.. traction )

soundguy

 

[leftturn7m]

[/QUOTE]Take yer atv, tach it out to max rated rpm under heavy load.. I bet it's lifespan will be measured in units -LESS- than hours..


soundguy[/QUOTE]

I like that!! More like the ATV lifespan would be measured in pieces.

 

[jmfox]

It is the gearing, but in order to avoid a motor twisting itself into a knot, it must be heavy enough to handle the gearing. If you put an engine designed as a match for an ATV centrifugal clutch into a tractor, something has to give. It won't be the tractor transmission and solid axles. This is one of the reasons why manufacturers who do everything inhouse have more reliable equipment. Having control allows a manufacturer to assure that all components are balanced and compatible.

jmf