How Does This Work? Voodoo Engineering?

[Seven Gables]

There's no voodoo engineering going on, you guys just don't have your facts straight. Absolutely zero chance that Kubota is going to lie about their engine performance.

Product Detail | Product Search | Kubota Engine Division

This page offers industrial diesel engines and these for generators.

global.engine.kubota.co.jp

(there are several different versions of their v1505 engine, but it should be this 30.8 HP one in the LX3310)

Y

There's no voodoo engineering going on, you guys just don't have your facts straight. Absolutely zero chance that Kubota is going to lie about their engine performance.

Product Detail | Product Search | Kubota Engine Division

This page offers industrial diesel engines and these for generators.

global.engine.kubota.co.jp

(there are several different versions of their v1505 engine, but it should be this 30.8 HP one in the LX3310)

i misread the tractorgear website , it states torque 84.6 at 2000rpm not 77ftlbs

 

[TMGT]

Well thats odd. On the Kubota spec sheet, they list the engine as the V1505-CR-TE5-D36R1, which is the turbocharged version that makes 44 HP. But the lx3310 should only has 30.8 HP. Maybe they did confuse something after all.

Does the LX3310 have a turbo?

Product Detail | Product Search | Kubota Engine Division

This page offers industrial diesel engines and these for generators.

global.engine.kubota.co.jp

The 44hp is at 3000rpm, the LX3310 has a rated rpm of 2500 which is part of the reduction, I'd guess the remainder of the lowered HP is through a milder tune to hit a target output/increase longevity. Kind of like they do with the reduced power on a lot of cab and chassis trucks compared to their pickup counterparts.

 

[deezler]

Ok so it looks like yes, the lx3310 does have the turbo V1505. Likely de-rated some vs the industrial application engine, indeed. Thats a nice engine....

 

[hosspuller]

I think being lost is the use of the tractor. Regardless of the peak Hp, many people use the tractor PTO. That limits the engine rpm to the number that produces 540 PTO rpm. The designers will have selected the gearing to best use the engine at 540 PTO rpm. Compare ratings at that engine speed.

 

[CobyRupert]

According to this calculator:

Spicer Horsepower and Torque Calculator

The Spicer Horsepower and Torque Calculator will quickly calculate approximate horsepower or torque, depending on your selections.

spicerparts.com

Calculate horsepower from torque:
Deere: 77.2 ft-lbs at 2500 rpm is: 36.7 Hp (Deere says 37.2Hp/30Hp (PTO))
Kubota: 77.7 ft-lbs at 2500 rpm is: 37 Hp (Kubota says 30.8Hp/27Hp(PTO))

Calculate torque from horsepower (assuming listed Hp is at 2500rpm….but is it?):
Deere: 37.2 Hp at 2500 rpm is: 78.1 ft-lbs
Deere (PTO): 30 Hp at 2500rpm is: 63 ft-lbs
Kubota: 30.8 Hp at 2500 rpm: 64.7 ft-lbs
Kubota (PTO): 27 Hp at 2500 rpm: 56.7 ft-lbs

Interpret away…

I’m confused by how Kubota gets 77.7 ft-lbs at 2500 rpms out of a 30.8 hp engine when math says it takes 37Hp?
Perhaps if 2075 rpms was engine speed for 540 rpm (PTO) and it still produced 77.8 ft-lbs (assuming a flat torque curve) that would equal 30.8 hp, but would you call it a 30.8Hp engine if it produces 37 Hp at 2500rpm?

 

[LouNY]

Without a complete torque and hp curve from the manufacture all the calculations are just playing with numbers.
Many tractor engines do not develop maximum torque at their rated rpm,
quite often the torque peak will be several hundred rpm below the hp peak.
Many times 540 rpm PTO engine speed will be below the hp peak and above the torque peak.
And don't forget the value of displacement on torque curves.

 

[CobyRupert]

Agree Lou. It seems that their horsepower numbers aren’t tied to (qualified by) a particular rpm.
My understanding is Horsepower numbers are often from a “bench test”, done without standard intake, exhaust, pollution (etc..?) systems that engine has when installed on tractor. That is, differences between engine and PTO horsepowers are not just losses in transmission.

 

[ROUSTABOUT]

One very important figure is left;
what rpm did they get these numbers at.

It be done say 2500 on the post.

 

[ROUSTABOUT]

I was comparing the specs between a John Deere 3038E and a Kubota LX3310 and I'm not understanding how these numbers work. If anybody has any ideas please share them.

John Deere 3038E:
Engine Torque at rated speed: 77.2 ft-lbs
Rated Speed/RPM: 2500
Engine horsepower: 37.2
PTO horsepower: 30
Weight: 2,222 lbs

Kubota LX3310:
Engine Torque at rated speed: 77.7 ft-lbs
Rated Speed/RPM: 2500
Engine horsepower: 30.8
PTO horsepower: 27
Weight: 1,918 lbs

What is it to not understand? The numbers are right there.

 

[m1garand762]

Nobody has gone down this road yet but these are 2 completely different frame sized machines. If you compare like for like the l3301 will clobber the lx3310 all day long. Roughly the same ponies but many more differences. I just had trees cut down and the tree guy brought his lx3310 with his wicked 55 for clean up. I had my l3901 and wicked 55 out and he ran both. Horse power aside he flat out told me my machine would out work his all day long.