5' or bigger implements by Compact Tractors?

thegreatrandini · Apr 26, 2005

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

That's why the Japanese went with 4wd and multi speed pto's to till up the wet rice fields.....They run 4ft or even 5ft tillers with 15 pto hp. In mud? amazing I think!!!!

nomad · Apr 29, 2005

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

( Take a volume of air at 25 deg C and 1 atm pressure and compare it to any other volume of air at 0 deg C and 1 atm pressure. The cooler air will always have a higher density. Right? /forums/images/graemlins/smile.gif
)

Right. But, you are changing the volume. If it is a rigid box (constant volume), the density of air will not change, doesn't matter whether you heat or cool it.

Pooh Bear says:
(
I believe my original questions was
what are you wanting to pull and how big is it.
And what are you wanting to pull it with.
)

My answer was: to pull any item with designed (shown on brochures) HP of 35-45. At the beginning, I gave an example. Drum mower with 5' size. Before compact tractors appeared in the market, these sellers were telling the end users that these 5' sized drum mowers were requiring about 35-45 HP and they would not be advicing you to pull them with 30 and less HP tractors. But, now, these sized mowers are being sold to owners of compact tractors too, which has an HP less than 30 HP. What have changed? Only marketing words. So, why not using all other implements not categorized under "compact implements".

Spiffy · Apr 29, 2005

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

P1V1/T1=P2V2/T2 no matter which scenario use you it in; same thing in the end. /forums/images/graemlins/crazy.gif

The real issue anyway is that by charging an engine you can probably overcome some engine limitations (i.e squeeze more HP from the same engine).

Now as Soundguy and and others eluded to; is this safe...or even practicle?

I still say try it without charging and post the results good, bad, or ugly.

If you have the particular combination of PTO and pulling work that drags down the engine without causing a nasty "pucker factor" to your safety or the tractors longevity, charging may be the answer. For most situations, I'm guessing this combination does not exist, but I'd love to see your results.

Waiting on your results,

nomad · Apr 29, 2005

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

Are we lost in this discussion about density change with temperature change? Or, am I the only one not understanding you on this very simple issue? Yes, for air (actually, for ideal gas,) PV/T = constant = P1V1/T1 = P2V2/T2. But, in our case (rigid box), V1 = V2 = V = Volume of rigid box. Since mass M of air in this rigid, closed box is same, a constant M (constant) / V (constant) = Density = Constant and doesn't matter whether you increase/decrease P2 or T2. Constant volume process in a closed cycle can be considered as a rigid box process in which density doesn't change. Combustion (in gasolines) and heat rejection stages (in both of gasoline & diesel) are constant volume processes, that is, the density doesn't change even though temperature increases (during the combustion) or decreases (during the heat rejection after expansion of gas.) See attached P-V diagram of a tractor (4-1: compression, 1-2: combustion, 2-3: expansion, 3-4: heat rejection.) (In gasoline, 1-2 stage too is constant volume process.)

Concerning safety, probability of giving some damage to the tractor frame, body, etc when increasing HP by charging; I already gave 5' drum mower example. Another one; I have seen on a forum here someone is pulling a 60"-72" tillers with a compact tractor. Any problem occured? No. Then, why should a problem occur when pulling the same tillers, with a charged compact?

Spiffy · Apr 29, 2005

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

OK, I'm now convinced the theory of Nomad finding enjoyment from the "knee jerk effect" is right!

I think the density debate was started over intercoolers not the actual combustion chamber; here [regardless of assuming open or closed system] you are putting more air into the cylinders - the intercooler only changes the "side-effect" that one either T or P must change to achieve this.

Granted the equations assume ideal gas, but the analogy applies quite well to that scenario.

And, yes burning more air/fuel [regarless of diesel or gas] can lead to more hp from the same engine. If you're not completely burning the fuel [judging from your diagram, I presume we're still talking diesel] under heavy loads, you may even realize some efficency by charging. I don't think that was really questioned.

Now where I'm missing the simple point....if enough people have tried these implements succesfully, then isn't that question already answered without the charger?

Back to your orginal question "Prove I am wrong": I have little doubt it's possible to get more raw power from a given engine....but it only counts if you can [and need to, as opposed to the attachment working fine without] use it.....

With any particular tractor and implement combination the answer may be different, but I'd say post the before and after results and "prove the theory right." /forums/images/graemlins/grin.gif

nomad · Apr 29, 2005

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

Okay, enough. Lets stop talking technical details here. Am I understanding you correct in that most of you think turbochargers are not so useful for tractors, especially for compact tractors? Then, why are already many many many chargers being added to older utiliy tractors and most of new utility tractors are coming with turbochargers? Don't tell me that they are converting tractors to race vehicles.

Spiffy · Apr 29, 2005

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

Won't speak for the rest, but I never said not useful. I just don't think it is a "magic answer" to converting a 25Hp tractor to its larger counterparts [unless, as mentioned earlier, you have the smaller HP of otherwise identical models].

In the case of new machines, I'm sure it's either an example of being able to advertise a couple more HP, or use a dimensionally smaller engine for the same tractor.

Don't know about the older ones, but I'll say if you're willing to accept the limitations, it may be useful.

nomad · Apr 29, 2005

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

I admit I don't have much info on current market of turbochargers. I have heard many stories such as; Many old tractor owners have added chargers to their tractors. Some car owners are increasing their car powers from 150 HP to 300 HP. etc. I think, in the older tractors, chargers are being added mainly to lower fuel consumption (per mile or "per work") and HP increase not more than 20%. This means only efficiency increase rather than burning more fuel like it is done in cars with increased powers from 150hp to 300hp. Turbochargers are not available in compact tractor market?

thegreatrandini · Apr 29, 2005

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

I would rather not push my little 2 cylinder any harder? It already has high torque for a little guy.... Those old Japanese engineers are smarter than me any how....

Pooh_Bear · Apr 29, 2005

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

( Since mass M of air in this rigid, closed box is same, a constant M (constant) / V (constant) = Density = Constant and doesn't matter whether you increase/decrease P2 or T2. )

But mass is not the same. It is increased.
More oxygen = more mass = more density.

Forget turbochargers, add NOx.
Now that I'd like to see. (just not on my tractor).

Pooh Bear