5' or bigger implements by Compact Tractors?

[Soundguy]

Re: 5\' or bigger implements by Compact Tractors?

I'll also add that even if you accomplish adding more engine HP to a tractor.. you havn't increased the transmission or pto durability any. In my example of the 100hp 8N.. you still are stuck with channeling that hp thru a 30hp rated tranny, rear end and pto shaft...

Soundguy

 

[Soundguy]

Re: 5\' or bigger implements by Compact Tractors?

</font><font color="blue" class="small">( but I don't see how the turbo will increase the PTO hp either. My logic is this, to turn the PTO at 540 rpm you have to have the engine)</font>

I gotta agree with the others on this.

I own a tractor that comes in a turbo / non turbo configuration.. same engine, etc. Different hp and pto hp specs.

It's also common to have a tractors injector pump adjusted up for more hp.. that translates into more pto HP. At least one of the big 3 brands just switched it's model numbers around and increased a couple hp on each model.. and it's the same engine.. just more fuel.

I've heard there are a few chineese tractors in the same category.. same engine used on two models.. and there is a modest hp difference between them due to injector setting.

PTO hp is always a direct calculation or measurment off of gross engine hp, given all else equal. If the engine makes more hp.. the pto has more hp available. The engine responds and handles load better without rpm loss with more hp.. etc.

Soundguy

 

[JoeinTX]

Re: 5\' or bigger implements by Compact Tractors?

Ol' Nomad....at it again....

I've "spoken" with Nomad before on a different forum and he's generally asking inane, open ended questions like these.

Just exactly what do want to accomplish with a ridiculously upgunned small tractor? Is any real implement more the 6-7' applicable on a CUT regardless of HP? Uh, no.....maybe a hay rake, but why the trouble.

File this under "not worth wasting a brain cell on"...

 

[nomad]

Re: 5\' or bigger implements by Compact Tractors?

I see, this weekend, I will be busy with enlightening some people here. First of all, let me summarize HP & Torque & RPM relations briefly.

HPt = Theoretical HP (perfect HP, when efficiency is 1, when fuel is burned completely, etc.)

HPr = Real HP

T = Torque

R = RPM

E = Efficiency

Formula is:

HPr = HPt x E = T x R

When you add a turbo actually you are increasing E (efficiency) as you are recovering heat loss and by heating inlet air/fuel mixture, better combustion in the engine. So, you have a theoretical HPt that is maximum and now, with a turbo, you have a bigger HPr. Engines and vehicle components are (must be) designed according to HPt, not to HPr. This means you are allowed to increase your real HPr up to theoretical HPt. If you can.. Turbo can. Current turbos in the market can increase HP by about 20% (still under theoretical HPt of course.) SO, don't worry about increasing your engine's real HPr, you will still be under the design, theoretical HPt level. Having said these; now, lets see where your increased amount (20%) of HPr will go if you increased it by a turbo;

HP = Torque x Rpm
HP will stay constant at any point of the system (at crankshaft exit, at flywheel, at pto output, etc). Depending on your gear, flywheel, etc you will increase either T or R, but their multiplication (i.e. HP) will be constant. In cars, R is increased, therefore T is lowered. In tractors, T is increased and R is lowered. So, if you increase HPr by 20%, and if you keep Rpm same, where will that extra HP go? It will be converted to Torque that will carry the load. Okay, everythings up to now is clear? There will be no strength, stress, fatique, durability problem as our increased real HPr is still under theoretical HPt that can also be considered as design HP if your tractor is a well designed, quality tractor.

Now, why am I bringing such an issue here? Someone had asked me to send him some drum mowers and tillers. I offered some (between 5'-7' sizes) which are designed according to 35-45 HP. He said "these sizes are big as we will use them on compact tractors which have >30HP". I said you can of course use these 5 - 7 ft implements by your compact tractor. And, if you do that, you will get a better pricing. Dealers/manufacturers (of such 35-45 hp implements) out there must be rubbing their hands now. They will be selling much more quanitities of bigger sized drum mowers, tillers, etc to compact tractor owners. Now, this is serious thing if you believe me? I go out now. Later. have a good weekend.

 

[hobbyfarm]

Re: 5\' or bigger implements by Compact Tractors?

Spiffy,
Don't forget, you've got to get the extra power to the ground. All the power in the world does nothing without a way to realize the traction. Larger meats or even duals would help get the added power to the ground.
That would look cool, a CUT with duals. /forums/images/graemlins/cool.gif

 

[hobbyfarm]

Re: 5\' or bigger implements by Compact Tractors?

</font><font color="blue" class="small">( Sometimes I think Nomad just posts these questions to see us 'knee-jerk' )</font>

Absolutely, very well said Soundguy! /forums/images/graemlins/blush.gif /forums/images/graemlins/grin.gif

I'm sure Nomad is having a good laugh with us "armchair engineers." /forums/images/graemlins/grin.gif /forums/images/graemlins/grin.gif

 

[Pooh_Bear]

Re: 5\' or bigger implements by Compact Tractors?

</font><font color="blue" class="small">( When you add a turbo actually you are increasing E (efficiency) as you are recovering heat loss and by heating inlet air/fuel mixture, better combustion in the engine. )</font>

Nope, sorry Nomad, all the turbo is really doing is increasing the oxygen flow to the engine. Heated air is less dense so you don't want to heat it. Compressing the air with a turbopump causes it to gain heat. This is the purpose of the intercooler in a car. To dissipate the heat and keep the charged air as dense as possible.
Part of the boost of adding nitro is the cooling effect of the sudden decompression of the NOx.
Cooler air is denser = more oxygen = better combustion = more power.

Remember the law of diminishing returns.
Don't care how much HP you make. You can only get so much to the ground.
And you can only add so much weight until you break something.

Pooh Bear

 

[Spiffy]

Re: 5\' or bigger implements by Compact Tractors?

<font color="blue"> That would look cool, a CUT with duals </font>

So worried about a "back flip" completely forgot to mention the traction issue!

With duals is it still a <font color="red">C</font>UT? I'm sure it's been done, now if they'ed only admit it and post pictures. /forums/images/graemlins/cool.gif

I was going to babble about the "efficiency" too, but looks like pooh bear did it with less babble than me. /forums/images/graemlins/smile.gif

 

[nomad]

Re: 5\' or bigger implements by Compact Tractors?

Pooh Bear, increasing the oxygen flow to the engine is covered in "increasing efficiency" of the engine. Why do you need to increase the O2 flow to the engine? It is because you want to burn unburned fuel remaining in the cylinders due to lower combustion efficiency. Turbo's main purpose is "to increase efficiency" and to do that, it supplies more oxygen into cylinder, BUT it also recycles/recovers heat loss happening in the exhaust manifold to be used in the inlet air or air+fuel mixture again. Heating the inlet is wanted because combustion chamber is hot and adding a colder material lowers the efficiency (re: equilibrium of states & entropy).

Cooler air is denser? It depends on your system; open or closed system. Consider a constant rigid volume box, a closed system. Heat the box. Since total mass of air inside the box and volume of the box don't change, therefore the density will not change even if you heat. Only temperature&pressure inside the box will change. Note that internal combustion engines are considered as "closed" systems (not open system) when their thermodynamic calculations of complete cycles are done. So, heating the inlet (air or air+fuel mixture) in internal combustion engines is desired (to increase its temperature as close as possible to combustion temp. for thermodynamical equilibrium, hence better efficiency.)

 

[hobbyfarm]

Re: 5\' or bigger implements by Compact Tractors?

<font color="red"></font>Unverferth Small Diameter Duals

Spiffy,
You mean like this? /forums/images/graemlins/grin.gif