B2630 or B7800?

[davitk]

Not to throw the topic off track, but I hear alot about tractor horse power and nothing about torque. Seems to me, the reason we all run diesels is because of the increased torque over gasoline. So, if that increased torque is so important, maybe someone can point me in the right direction here?

If my math is correct, 30 hp is 13% greater than 26 hp, but I would guess that in terms of actual tractor performance the difference would be less. Bear with me now, I am just a dumb carpenter, not a mechanic or engineer, but it seems to me that since the 3 cylinder would have 14% larger cylinders than the 4 cylinder (26 hp divided by 3 cyl = 8.7, 30 hp divided by 4 cyl = 7.5, 7.5 divided by 8.7 = 86%), that the larger cylinder size would somehow be translated into increased torque output.

Does any of that make any sense? You can all laugh and call me a goof, but I was just sitting here thinking......

 

[Crash101]

A tractor performs its work at higher RPM's. In order to obtain the ideal 540 rpm PTO speed, many tractor engines are turning upwards of 90% of their maximum. At higher RPM's any internal combustion engine is making horsepower. Torque is a measurement of the twisting force but horsepower is a measurement of that twisting force times speed (RPM'S) we often refer to torque in our trucks. A vehicle of which does it work by pulling a load from dead stop up to (and of course maintaining) highway speeds. That acceleration is where that twisting force (torque) is important. It's fairly easy to maintain that speed once it's reached so horsepower does not play as big a role. Our tractors do their work turning that PTO at a given speed. It needs a certain amount of power to maintain that speed (horsepower). Torque will get it up to speed, horsepower will keep it there.
As far as 3 cylinders producing more downward force because of a larger size piston or crankshaft lever, remember a 4 cylinder will produce 33.3% more downward motions in a given timeframe, therefore offsetting the additional work performed by the larger 3 cylinder.
It is certainly my contention that the above statements are not necessarily true and therefore I make no claim to the validity of said statements. Neither do I accept any responsibility of any consequences of actions taken by anyone regarding acceptance of above mentioned statements.
(in other words it's just a theory)

 

[2Botas]

Not to throw the topic off track, but I hear alot about tractor horse power and nothing about torque. Seems to me, the reason we all run diesels is because of the increased torque over gasoline. So, if that increased torque is so important, maybe someone can point me in the right direction here?

If my math is correct, 30 hp is 13% greater than 26 hp, but I would guess that in terms of actual tractor performance the difference would be less. Bear with me now, I am just a dumb carpenter, not a mechanic or engineer, but it seems to me that since the 3 cylinder would have 14% larger cylinders than the 4 cylinder (26 hp divided by 3 cyl = 8.7, 30 hp divided by 4 cyl = 7.5, 7.5 divided by 8.7 = 86%), that the larger cylinder size would somehow be translated into increased torque output.

Does any of that make any sense? You can all laugh and call me a goof, but I was just sitting here thinking......

Here is the info you are looking for although this is based at peak HP rpm. I would imagine the torque advantage of the B3030 would be even greater at a lower RPM.

Torque=HPx5252/RPM

B2630=26BHP@2800 RPM
B3030=30BHP@2600 RPM


B2630- 5252x26/2800= 48.76LbFt of torque

B3030- 5252x30/2600= 60.6LbFt of torque

 

[2Botas]

A tractor performs its work at higher RPM's. In order to obtain the ideal 540 rpm PTO speed, many tractor engines are turning upwards of 90% of their maximum. At higher RPM's any internal combustion engine is making horsepower. Torque is a measurement of the twisting force but horsepower is a measurement of that twisting force times speed (RPM'S) we often refer to torque in our trucks. A vehicle of which does it work by pulling a load from dead stop up to (and of course maintaining) highway speeds. That acceleration is where that twisting force (torque) is important. It's fairly easy to maintain that speed once it's reached so horsepower does not play as big a role. Our tractors do their work turning that PTO at a given speed. It needs a certain amount of power to maintain that speed (horsepower). Torque will get it up to speed, horsepower will keep it there.
As far as 3 cylinders producing more downward force because of a larger size piston or crankshaft lever, remember a 4 cylinder will produce 33.3% more downward motions in a given timeframe, therefore offsetting the additional work performed by the larger 3 cylinder.
It is certainly my contention that the above statements are not necessarily true and therefore I make no claim to the validity of said statements. Neither do I accept any responsibility of any consequences of actions taken by anyone regarding acceptance of above mentioned statements.
(in other words it's just a theory)

You have some good theories there. The main thing to remember is that Torque and horsepower are directly related. The effective twisting power of a engine is the torque. Horsepower is more of a time measurement(it is basically the amount of torque that is applied over a given period of time/speed). By having a higher HP/Torque ratio you can take advantage of lower gear ratios and a broader RPM range to work with. This setup works great in a car, but in a tractor you are usually only working the engine hard at PTO RPM. So the amount of torque at PTO RPM would be the best number to look at.

 

[Northland]

I have the B7800 and love it but I would probably been just a happy or happier with a 2630 or 3030.

Over the course of the many years of ownership the price difference won't mean much.

I saved money buying the B7800 but put a toothbar and bucket grapple on the B7800. since I use thoes two add-ons all the time they are worth more to me then PC and the other 2630/3030 features.

 

[machmeter62]

Northland: I think Kubota makes quality tractors, but what I don't understand is why they started putting "inching valves" on the three points, and not advising it in the sales literature, on the economy tractors? It should be there in BOLD PRINT, explaining the function? It is a "stone age" system in the 21st century! The jerking lift cancels any savings, and defeats a lot of advantages with ground engagement implements, i.e. snow plowing, scraping, grading, tilling, and etc. To me, it would be a PITA even putting implements on? I still have my first tractor, a 39' Ford 9N with position control in my fleet, that had it's 68th birthday!

Maybe it's the same design team that put plastic on the earlier BX's for cost savings, that decided they could save more money with the inching valves too? Kubota quieted a lot of unhappy owners with the economy L series when they first produced it with the inching valve, and then replaced it with position control free, to quiet the crowd?

 

[Shantycoke]

Hi Dave,
I have a B7800 and am more than happy with it. The tach, temp guage, fuel guage, and cruise is all I need to keep me happy. This thing has handled everything I put in front of it, and had muscle to spare. **** thing would probably climb a tree if I let it. I have a 5 foot hog, and it clears small locust trees while going up hill. 5' box blade is no problem for it, and yet it's comfortable enough to mow 5 acres with a 60" mmm. As far as the loader goes, I haven't been able to over load it yet. You'll be more than happy with whatever you buy, but the way I see it, the less gadgets you have, the less chance of problems. Good luck my friend,
Pat

 

[Northland]

Northland: To me, it would be a PITA even putting implements on? I still have my first tractor, a 39' Ford 9N with position control in my fleet, that had it's 68th birthday!

Good point machmeter! I have had my carry-all on so long I forgot how changing implements drove me crazy! The telescoping hitches and ratcheting leveler alone make the B2630/3030 worth buying over the B7800. I have my B7800 with carry-all in the garage beside the wife's car and it sure would be easier to park if I could easily remove and leave the carry-all outside.

On that note TSC's head office just shipped me a new prototype quick hitch that they are planning to sell in all their stores within months. Apparently it's spring loaded so you don't have to get off your tractor to lock your implement in place. It's suppose to sell for $100 or so.

I had bought the TSC SpeeCo QH and my implements at the local MI UP TSC and when none of them worked together I complained to TSC's head office in Nashville. That brought me a call from their implement product manager. The deal is I keep the hithes and write a review for them. I should have them in a week so I will post my review here as well

 

[canoetrpr]

Good point machmeter! I have had my carry-all on so long I forgot how changing implements drove me crazy! The telescoping hitches and ratcheting leveler alone make the B2630/3030 worth buying over the B7800. I have my B7800 with carry-all in the garage beside the wife's car and it sure would be easier to park if I could easily remove and leave the carry-all outside.

I agree 100%. A quick hitch of some sort does help substantially but I will still take the racheting leveler not needing a wrench with the turnbucklers. That said once hydraulic toplink in installed and I get one of the stabalizer bars for my Pats, I think those will be unnecessary.

Overall I think they throw in more than enough for the price difference between the B3030 and the B7800 - JMHO.

The only REAL issue regarding the economy L series that Kubota has had is attitude and communication. Once the valve was changed (which they have done for practically everyone that has complained - some with less and others with more hassle), my tractor has been great. What has not been great is the rheteoric from Kubota corp. They could have wrapped the same messages / points with a better attitude instead of making you feel like you bought a 'economy tractor' and so "deal with it".

The issue of the PTO breaking is not widespread at all. There is the odd issue of the PTO not turning off. There is one user (teg) who this has not been addressed for which I find INSANE - and is probably more a poor dealer than anything else IMHO. I think the odd issue like that will occur no matter the make or model. The problem is them not being resolved and 'economy tractor' rhetoric being laid on top of that.

I still think that the L2800 and L3400 are great value for the money and good solid tractors. Kubota sells a LOT for these machines. If I tell the guy down the street who bought one of the early JD 3x20 machines and had a front axle leak and a bad rockshaft valve that the biggest problems with my tractor were a jerky 3pt and a PTO which may or may not break.... he will laugh. The odd issues like this are not a problem if they are addressed properly.

 

[davitk]

I know I said I wouldn't go bigger than the 7800 or the 2630........

But I was at the dealer today and he showed me the L3240....... big mistake, I should've just smiled and walked away. Easily twice the machine of the B3030 that was sitting right next to it, and only 1,600.00 more (3,350.00 more than a B7800). HST, R-4's, LA514 loader with QA, delivered to my door $18,750.00.

And it will still fit through my barn door. How can I say "no"?