Engine torque (power) specs for Grand L's?

CT_Tree_Guy · Nov 29, 2005

Engine torque (power) specs for Grand L\'s?

Hi all - I'm having trouble finding the engine torque specs for the Grand L's. Unless I'm blind, they're not in my manual.

I might have found the "holy grail" in this part of a post:

"Torque ratings for the L30's, from the L3130 to the L5030 respectively. All are in ft lbs. 75.9, 79.9, 89.0, 107.8, 107.8, and finally 119.8 for the L5030. The L4330 and L4630 have the same engine and torque, just different injectors to give the more HP to the L4630."

I just want to make sure that is correct about the 4630 having the same torque as the 4330. What good is HP without torque? If this was done merely to have nice even HP intervals in the product lineup, without having to go to the trouble of stroking the engine, I'm a little disappointed in Kubota. Makes the 4630 seem like a very poor choice, since it's operating speed is 100 rpm's higher yet puts out the same torque as the 4330. When I saw that the two engines had the same displacement and stroke, I crossed the 4630 right off my "short list". Comments?

Thanks, John D.

Dargo · Nov 29, 2005

Re: Engine torque (power) specs for Grand L\'s?

That's cool. I've been wondering about that. My JD dealer has been telling me about how much more powerful a new 4720 cab model would be for me. I can see that the 4720 will have more PTO hp, but that is an area where I have not needed more power. Compared to my L5030HSTC, the 4720 cab really isn't going to weigh more, the 3 pt. hitch doesn't really pick up much more, and the loader isn't much stronger at all. I still don't know what the torque is on the JD 4720, but my JD dealer states that it is considerably more than the 5030. It very well may be as far as I know, but after comparing, I've found that only the PTO hp is significantly more than on my 5030. For what would be about 10k more money, I'm not seeing any reason to "upgrade" at this point.

Sully2 · Nov 29, 2005

Re: Engine torque (power) specs for Grand L\'s?

Its my understanding that HP..,"gets you going"...and torque " keeps you going"...

Its done all the time with larger engines...Cat C7 being one example. 300; 330 and 350 HP...all the same torque.

jmc · Nov 29, 2005

Re: Engine torque (power) specs for Grand L\'s?

Overall performance may be more complicated than HP and torque specs. Check out the attached link on torque rise and its effect on lugging ability.

torque rise

You're right about the lack of torque info by Kubota. Just checked my L series brochure and they list about everything but that.

Bob_Young · Nov 30, 2005

Re: Engine torque (power) specs for Grand L\'s?

With similar engine designs, engine cubic inch displacement is still one of the best indicators of performance capabilities. You'll notice both the L4330 and the L4630 have the same 134 cubic inch displacement. It's no surprise that peak torque is the same for both engines. Unless something is done to radically affect combustion pressures, it's almost a given.

Besides displacement, peak HP is also a function of RPM and fuel/air delivery. A turbocharger can really pack the fuel/air in at high RPM and the increased power being delivered is real but the effect on peak torque is nowhere near as pronounced. As I recall, normally aspirated engines usually have the best torque rise.

Like they used to say at the drag strip, "There's no substitute for cubic inches.". Or was it, "There's no replacement for displacement."?
Bob

Dargo · Nov 30, 2005

Re: Engine torque (power) specs for Grand L\'s?

( Like they used to say at the drag strip, "There's no substitute for cubic inches.". Or was it, "There's no replacement for displacement."?
Bob )

Maybe that's why I love the 502ci and 572ci engines I have in a couple of old muscle cars. /forums/images/graemlins/wink.gif

And, I grew up hearing the latter quote...

CT_Tree_Guy · Nov 30, 2005

Re: Engine torque (power) specs for Grand L\'s?

Re: Down to Orange [Re: cart99] CT_Tree_Guy
#778237 - 11/27/05 11:03 AM

I like to pick out little nuggets like that from the stats. Here's one - the L4630 has the same displacement as the L4330, with the extra hp tweaked somehow. There's no replacement for displacement , I wouldn't even consider a 4630.

**************************

( I grew up hearing the latter quote... )

Me too! /forums/images/graemlins/smile.gif

mike69440 · Nov 30, 2005

Re: Engine torque (power) specs for Grand L\'s?

( With similar engine designs, engine cubic inch displacement is still one of the best indicators of performance capabilities. You'll notice both the L4330 and the L4630 have the same 134 cubic inch displacement. It's no surprise that peak torque is the same for both engines. Unless something is done to radically affect combustion pressures, it's almost a given.

Besides displacement, peak HP is also a function of RPM and fuel/air delivery. A turbocharger can really pack the fuel/air in at high RPM and the increased power being delivered is real but the effect on peak torque is nowhere near as pronounced. As I recall, normally aspirated engines usually have the best torque rise.

Like they used to say at the drag strip, "There's no substitute for cubic inches.". Or was it, "There's no replacement for displacement."?
Bob )

With a little pulley change I'm up to about 590 HP and 550 Fl-lbs of torque and manage to get over 20 MPG from a little 281 Cu In 32 Valve V-8 Supercharged Too.
20 MPG Average over 10 tank fulls, try that with a big Block. PS I've owned several!
See attached!

N80 · Nov 30, 2005

Re: Engine torque (power) specs for Grand L\'s?

It would seem to me that rear wheel (not flywheel) and PTO torque would be the most important info about a tractors power, other than what you might guess based on displacement. As has been mentioned this data is hard to find.

But even with that data, the weight of the tractor has to be factored in too.

I would also think that you'd like to see most of your torque at fairly low rpms, unless you ran your machine in long, smooth, flat fields all the time.

I must say, however, that anymore torque or hp or whatever, in my little L4400 and I'd just end up tearing it up. /forums/images/graemlins/grin.gif

slowzuki · Nov 30, 2005

Re: Engine torque (power) specs for Grand L\'s?

N80, you are getting close, tractor performance for dragging things is measured by drawbar pull and hp. The pull is the max force that can be generated at teh drawbar. The hp governs how fast you can move it along.

For spinning things the pto hp tells you everything you need to know as it is always at 540 rpm.

So technically in a tractor with all its gearing, torque means hardly a thing whereas torque rise will be noticable. The quality of governor built into a diesel engine can be easily confused with how much torque a diesel has due to feeling loads knocking the speed down.