Oil & Fuel Diesel Tractor HP vs. ATV or Car

[rjgogo]

give me a long enough lever and I can move the world. ;-)

 

[Rara Avis]

"Give me a place to stand on, and I will move the Earth." Archimedes

 

[slaveToHorses]

If the two engines are rated at the same brake hp and you add the correct gearing to match speeds, and you compensate for the change in weight, YES they will pull the same in the test when operated at their peak hp.

In real life there are a few other items, as you can use the weight of the big dozers rotating engine mass to smooth out small blips that would stall a light atv engine. The diesel engine would have a very flat torque curve so it wouldn't stall if you slightly reduced RPM's. And there are a few other little technical items.

Yup, back to torque, where theory and practice collide, like the ability to run at low enough rpm to actually use the gearing necessary to move a heavy tractor very slowly and pull very hard at the same time.

 

[GaryCrowell]

I have a hard time believing an ATV produces 56 HP. Most 350-400cc class ATV's run about 13-15 HP. That being said, HP is HP and a 56 HP motor will do the same work whether it's in a tractor or an ATV. What was said earlier was also true, an ATV motor producing 56 HP will be going all out and will grenade itself shortly running at it's rated power. A tractor motor rated at 56 HP will run all day long and never break a sweat.

 

[tiger9297]

Gary,

This day and time 56 hp for an ATV is quite common. Once the ATV's hit 500cc's 10-12 years ago they got up into the 40+ hp range. I have a 500cc that's rated at (I think) 48 hp, and as of today 500cc's is mid-size. Take a look at the hp rating of a 1000cc motorcycle. WOW!!! They are up at 150-200hp!!!!! Jet ski's are the same way. I think Sea Doo (sp?) has one that's 220+ hp.
I think comparing two trucks is more accurate. I have a K5 Blazer that I just built an engine for. It's a 388 stroker and puts out close to 500lb ft. of TQ and about 400 hp. I built it to tow my camper. I could have put another cam and a different set of heads and gotten 600+ hp and around 300 lb. ft. of TQ. More hp. but much less TQ= less pulling power with more HP.

I also have a IH Cub Cadet with a 16 hp cast iron Kohler engine. Not much HP but LOTS of TQ. I can hook it up to my loaded utility trailer and it doesn't even know its back there. My 48 hp 4 wheeler, while it will pull it, definitely knows its back there.

I guess I'm saying the original question does not provide enough info. b/c you are comparing apples and oranges. When comparing pulling power, one simply cannot look at HP only and make a determination. TQ must come into play.

"Horespower sells cars- Torque moves them down the road"

 

[Egon]

I read the article Moss.

 

[Patches]

MR- Thanks muchly for the most informative, and easily understood, explaination of the torque/horsepower relationship I've ever seen

 

[RWolf]

BTW; slowzuki I do understand the differences between HP and torque and I like many others tend to use the terms interchangeably. Like I said in my earlier post I over simplified it and I knew it wasn't completely accurate. But the basic math "priniciple" still remains the same whether your talking HP or torque. I don't mean to be nit-picky and if I'm wrong I'm wrong. Through gearing if you half the speed you are going to double the work available. That being said this is a great forum for getting and giving information.

 

[RobJ]

I guess I'm saying the original question does not provide enough info. b/c you are comparing apples and oranges. When comparing pulling power, one simply cannot look at HP only and make a determination. TQ must come into play.

"Horespower sells cars- Torque moves them down the road"

Finally something that makes sense. Two engines designed to do totally different things. Search back in the archives for the 30hp diesel tractor compared to a 30hp gasser tractor. Some fun reading there.

If I recall Polaris or Bombardia (whatever) had a diesel ATV. A single cylinder. Bet that was f-fun t-to ride-ide-ide, I worked on some 1 cylinder diesels and the flywheel was over 100# just to smooth it out....some Don't know it there are anymore out there. But some of the new ATV's running power steering and such are going to need the torque.

HP looks good on a dyno IMO.

 

[VTSasquatch]

I did read the article Moss. Thanks. I got lost though when the author talked about the water wheel. I don't really understand why all that torque couldn't be geared to turn a shaft faster without the huge loss of energy. Or why a fast motorcycle engine couldnt be geared down to produce more torque at the wheel. Anyway, I think I get the jist. Apples and oranges. One is made for one task and one for another. I used my atv to pull a 500 lb disc harrow and it could move it well. I am sure a tractor would be better though.

The atv was stolen overnight so I won't be able to compare them side by side. The worst part is that I'm told that my homeowners insurance won't cover it. It was a $7K machine with only 300 miles on it. I hate theives too! (saw the other thread.)