More Horsepower, Same Cubic Inches?

B2400 · Nov 23, 2004

While looking at the specs for the new B2630, I noticed it uses the same cubic inch engine as the B2400,7610,2410 series. The only differences I see are: 7610 uses D1105-E-D16 series engine and the 2630 uses the D1105-E2-21 series. Both engines are 68.5 CID, but the 2630 is rated at 26hp@2800rpm verses 24hp@2600rpm. Anyone have an idea what internal changes were made to up the HP or are 200rpm worth 2hp? If it's only RPM, it mght be time to turn up the pump!!! /forums/images/graemlins/cool.gif /forums/images/graemlins/grin.gif

aardvark · Nov 24, 2004

It's most likely the pump and engine speed. From a manufacturing standpoint, it would be cost prohibitive to make every D1105 engine with different internals, just for a 2-4 hp difference.

ronjhall · Nov 24, 2004

I noticed the B3030 has 23 PTO horsepower at the same RPMs as the B2910 which has 22 PTO horsepower.
Sure would be great if all that was required is a little tweaking of the pump.

B2400 · Nov 24, 2004

It would be interesting to know what they did for the 2hp gain. As you said,it could be in the pump output or timing or possibly up the compression a hair maybe? We need input from one of the interested Kub mechanics!!! Inquiring minds would love to know!!! /forums/images/graemlins/confused.gif

qqq · Nov 25, 2004

( Anyone have an idea what internal changes were made to up the HP or are 200rpm worth 2hp? )

Here's a quick review of Force, Work, and Power that might help explain what's going on here. Force is a measurement of how much push or pull we're applying. Say you have a really big turkey sitting on your counter, and it weighs 55 pounds, then its pushing against the counter with 55 pounds of force.

Now, if you lift the bird up one foot, you will have performed some work, 55 foot pounds of work to be specific. Now power is a measure of fast we can work. Way back when, James Watt came up with a measurement called Horsepower. His definition is 550 foot pounds per second. So if you lift the 55 pound bird up one foot in one second, you'd be developping 1/10 Horsepower.

Now if you were able to lift 10 of those turkeys up at the same time 1 foot in one second, then you'd be developping 1 horsepower, because you'd be doing 550 foot pounds of work per second.

Now, if your not quite that strong to lift the 550 pounds all at once, you could still develop one horsepower, if you can be fast. To do that, you'd need to lift the 55 pounds up one foot in a tenth of a second.

With engines, we're turning the crankshaft, and the amount of twisting force we get is called torque. In fact, when you add those performance mod.s to your tractor, and then have it dyno'd, the dynamometer is actually measuring torque. Its typically measured in foot pounds, and there's a formula that lets you convert torque to horsepower, its:

Horsepower = torque * revs/minute * 1/5252

So, is 200 rpm worth 2 horsepower? It depends on the torque. Using the formula above, 200 rpm will develop 2 horsepower if the torque is about 52.5 foot pounds. I believe this is in line with the torque numbers for the engines you've listed. I have a diesel car, and it develops 90 horsepower at 3750 rpm. That means I'm getting about 126 foot pounds of torque at that speed. If I could get another 200 rpm at the same 126 foot pounds of torque, I'd get a boost of almost 5 horsepower.

Bottom line, there's something called the torque curve:

I borrowed the image above from howstuffworks.com. When your idling, you're not making much torque. As you increase the throttle, the RPMs go up, and the the torque goes up. It's pretty rapid at first, but then it flattens out and starts to drop off. If you want to get more horsepower out of the same displacement, you need to try and make that torque curve flat through higher RPMs. To do that, you have to get more fuel into those cylinders. But you have to be careful, because more fuel means more force and more heat. Too much, and you burn a hole in a piston, or you break a connecting rod, etc. So, Kubota must have addressed these issues with their latest engine, and they've kept the torque curve up through higher RPMs

Hope this helps, and Happy Thanksgiving.

aardvark · Nov 28, 2004

I suspect that the extra two hp isn't coming from ignition timing, given that diesel's don't have spark plugs or distributors. /forums/images/graemlins/smile.gif It's most likely the engine speed and additional fuel added by the injector pump. If you can get service manuals for each engine, you can tell if compression is the same (I suspect it will be) just by cross referencing part numbers of the head, pistons, and head gaskets.

If you can get the engine to spin a little faster, I really doubt the engine would be hurt by the additional engine speed. These little engines are built pretty heavy for the power they make, and less than 3000 RPM is practically crawling for a well designed rotating assembly.

doc_cottom · Nov 29, 2004

Horsepower may be expressed as:

hp = torque in ft-lbs * rpm / 5252

hp = horsepower, hp
t = torque, ft-lbs
rpm = engine speed, revolutions per minute

This formula says that if you can keep the same amount of torque, then the more rpm you can turn, the more horsepower you get! Just the 200-RPM difference could produce the 2 horsepower.

This is why NASCAR engines turn such incredible RPMs. The faster the engine turns, the more power it can make.

One thing to always remember is that it is torque that breaks parts, not RPM.

Another thing to remember is that most horsepower claims are marketing untruths.

BillyP · Nov 29, 2004

I'd say it would be due to more fuel being delivered. I'm not familiar with the engine your talking about, so I'll use the engine used in the new 4000 twenty series JD tractors.

All 4 models use the same John Deere 4024T engine, 148.9 cu. in. turbo. All 4 models have the same operating speed of 2,400 RPM. But there's a HP difference in each model.

The 4120 has 43 HP, 4320 has 48, 4520 has 53 and 4720 has 58. That's a 15 HP difference between the lowest and the highest. Everything seems to be the same so (I think) it has to be the tweaking of injector pump.

slowzuki · Nov 29, 2004

Injection timing can give gains. Most newish diesels have retarded injection to reduce NOx emissions by decreasing peak pressures. This reduces the torque and hp.

( I suspect that the extra two hp isn't coming from ignition timing, )

SkyPup · Nov 29, 2004

Commonly, diesels have approximately 5 degress retarded timing to account for a decrease in NOx emissions these days.

However, all you have to do is increase the injection nozzles orifices diameter a couple of microns to add mucho horsepower and gobs of torque, either that or increase the crank injection window a couple of degrees to prolong the injection event.

Installing a new injection nozzle onto the injector with larger nozzle orifices is a super simple ten minute job and works excellent. There is no need to tweak the fuel injection pump or add more injection pressure with either of these methods.

Problem is they both increase the EGT under load, smoke alot more, and violate emissions laws, but the power output increase is spectacular. /forums/images/graemlins/wink.gif

aardvark · Nov 29, 2004

( This is why NASCAR engines turn such incredible RPMs. The faster the engine turns, the more power it can make.

One thing to always remember is that it is torque that breaks parts, not RPM.

Another thing to remember is that most horsepower claims are marketing untruths.)

I agree and disagree both. I agree that engine speed will make more power assuming the valve timing is specific to the range of speeds you want to make that power in. I assume you meant that though.

What I disagree with, is that torque breaks parts. I've seen the opposite, in that engine speed puts more wear on parts. Granted. for the typical diesel engine, which never sees engine speeds anywhere near what a gas engine ungergoes, your statement is correct. For a gas engine though, increasing engine speed increases side loading (due to radial forces at the rod journals) of the rotating assembly by the square of the crankshaft speed. Torque puts more torsional loading on the crank, rather than radial loading, which is designed to take that torsional stress. The higher engine speed requires more oil pressure to keep rod and main bearings alive, and the additional shaft speed causes valvatrain deficiencies to become more noticable. Based on my own experience, a 600 hp / 460 ft-lb, naturally aspirated, 333 CID Ford engine had much more wear than a 940 hp / 950 ft-lb turbocharged 306 CID Ford engine, upon inspection after dissassembly. The NA engine made power from 4500 RPM through 7500 RPM, while the turbocharged engine made power from 3000 RPM through 6000 RPM. The NA engine had alot more wear on the rod journal bearings and the main bearings than the turbocharged engine. It also had alot more wear on the thrust bearing, but that may be more clutch related than speed related. The rotating assemblies were both high quality, but the NA engine had all lightweight billet components, while the turbo engine just had run of the mill heavy duty forged parts. I guess I'm getting off subject here, but I am of the opinion that higher speeds kill engines faster than just alot of torque. Granted, for a diesel running less than 3000 RPM, it's pretty moot point, engine speeds that low won't hurt enything.

sneaky_pete · Nov 29, 2004

( What I disagree with, is that torque breaks parts. I've seen the opposite, in that engine speed puts more wear on parts.)

I agree with your disagreement, Aardvark. I've built and torn down quite a large number of hot-rodded Harley-Davidson engines over the years; these are (by modern standards) long stroke, low rpm, high torque motors, and in that regard maybe more like tractor engines than some others. The thing that kills a lot of hot rod Harley top ends is excessive piston speeds and the heat that generates. The longer the stroke, the higher the piston speed on every revolution to turn that puppy around to going the other direction at the top and bottom of every stroke. Long stroke / high torque engines make good, broad rpm range, usable power at lower rpms, but high rpms will destroy them.

You hit the nail on the head with your first paragraph; i.e., any engine must be designed as a package to make power for the desired purpose in the desired rpm range.

Pete

Ursushorribilus · Nov 29, 2004

( Commonly, diesels have approximately 5 degress retarded timing to account for a decrease in NOx emissions these days.

However, all you have to do is increase the injection nozzles orifices diameter a couple of microns to add mucho horsepower and gobs of torque, either that or increase the crank injection window a couple of degrees to prolong the injection event.

Installing a new injection nozzle onto the injector with larger nozzle orifices is a super simple ten minute job and works excellent. There is no need to tweak the fuel injection pump or add more injection pressure with either of these methods.

Problem is they both increase the EGT under load, smoke alot more, and violate emissions laws, but the power output increase is spectacular. /forums/images/graemlins/wink.gif )

Is this possible with any given tractor? I'd love to hear more about this... Would a mechanic at a dealership do this, or would you have to get a mechanic to do it privately?

art · Nov 29, 2004

I'd like to have him working for me if he can change out injectors that fast. Very close to being right but a lot of money could be spent before the right combinations of injectors as well as lines and many more possible combinations to gain and still not smoke, to much as some engines seem to have more room for clean expansion of horsepower then others. Most europeon design as well as orient are more conservative on the power and designed more for fuel economy.

SkyPup · Nov 30, 2004

It is really quite simple, there are only a couple of standard diesel fuel injector sizes (not sure if Kubtoa uses DENSO FIE system or their own design (I kind of doubt Kubota designs their own FIE though so most likely it is DENSO FIE but probably it is a Variable Closed Orifice P type pintle multi sac hole nozzle design of standard dimensions).

All you have to do is remove the entire OEM injector, screw off the OEM nozzle and replace with a standard nozzle having the same number of nozzle holes but larger nozzle orifices for more fueling per each injection event. These replacement nozzles could be sourced from other similar 'Bota engines with larger displacement and similar piston bowl design to keep the injection orifice geometry similar i.e. same number of holes in the same geometrical orientation to avoid hot spots in the combustion chamber). The IDI design of the current smaller 'Bota engines below 50hp only utilizes about a 3,000+ psi injection pump, whilst the newer larger Kubota diesels use direct injection at much higher pressures >10,000psi, although this technique will easily work with either design. There is no need to get entirely new injectors or mess with anything else, just change out the nozzle to new larger ones, it is extremely simple and only takes a few minutes.

On my two Volkswagen 1.9 liter TDIs with the Bosch VE37 rotary distributor injection pump (20,000 psi direct injection) and the Bosch VCO P type sac hole 17mm injectors, I just changed out the four injector nozzles in about 15 minutes. The OEM Bosch nozzle orifices were 0.158 microns which I replaced with new 0.205 micron nozzles. This increased the fueling event considerably with no increase in fuel pump pressure. Result was the OEM 90HP and 155 pounds of torque was increased to 140HP and 240 pounds of torque, this kind of power boost is very easy to detect with the butt dyno as well. Did this about four years ago after ordering the new larger injection nozzles from Italy and both TDIs are still running extremely strong with little decrease in fuel mileage (from 48mpg down to 42).

Here is where I purchased the larger replacement nozzles for less than $100:

http://www.bosio-estfb.it/pag3eng.htm

As you can see, you can get new nozzles for virtually any diesel engine if you know the engine design details well enough. I'll have to pull an injector on my L-3130 and take some measurements to see about ordering a replacement larger nozzle to boost the horsepower and torque sometime. /forums/images/graemlins/wink.gif

SkyPup · Nov 30, 2004

BTW, all of Kubota's FIE is sourced from NIPPON DENSO (including the fuel injection pump, the fuel injectors, and all associated fuel injection components) they do not make or design any of the FIE utilized on their diesel engines.

The injectors and nozzles on all their diesel engines are made by NIPPON DENSO and new or reconditioned nozzles cost as low as $10.00 each. /forums/images/graemlins/wink.gif

The Kubota L-3130 IDI engine is a part of their Super 03-M Series, specifically the D-1503 model with 91.5ci, 31hp, and 76 pounds of twist. The D1503-M has a bore and stoke of 83 x 92.4 mm and output of 31.5 hp at 2800 rpm. The turbocharged version of this engine has an output of 42 hp at 2800 rpm. The D1503-M-T is the only turbocharged engine in the series.

With a 25% increase in combustion chamber fueling this engine could be boosted to about 36-38hp and 100 pounds of twist. Whether or not the frame, tranny, and axles can handle that remains to be seen but since the turbocharged version achieves 42hp, the engine itself could easily handle the large injection nozzles..

In fact, upgraded larger injector nozzle assemblies could be sourced directly from the Kubota D1503-M-T turbocharged engine model. /forums/images/graemlins/wink.gif

SkyPup · Nov 30, 2004

Quite typically international OEMs design a standard diesel engine series and then outfit it specifically for different market niches in various environments (industrial, agricultural, marine, etc) to fit the desired load, altitude, application, emissions, etc.

So quite often the exact same engine can be utilized in four, five or six different configurations utilizing various customized specific injection pump pressures, injector nozzle sizes, with or without turbocharging, different fuel injection mapping, etc.

It is most easy to design a stationary industrial engine to operate under a constant load at a constant altitude at a constant temperature. It is much more difficult to design an engine for automotive, truck, or tractor use at widely varying loads and all different altitudes, in a multitude of different operational environments.

Just simply changing the injection nozzle orifce size is sufficent for the 2HP change you noted between the two Kubota engines, as long as the emissions still meet the intended market.

MessickFarmEqu · Nov 30, 2004

I think you have might just started the "tuner" tractor trend.

SkyPup · Nov 30, 2004

( I think you have might just started the "tuner" tractor trend. )

LOL /forums/images/graemlins/grin.gif

Anybody involved in a tractor pulling contest probably already knows all about this, if they've been winning........ /forums/images/graemlins/wink.gif

aardvark · Nov 30, 2004

I appreciate the info. I have never owned a diesel prior to this tractor, I've only had gas engines. I knew the diesel cycle is different than the four stroke cycle, and understood that the more fuel you put through a diesel engine, the more power it makes. I suspect it must also work that way with a diesel once you hit a point? When does the diesel supply exceed the air supply? I was also under the impression that as you put more fuel into a deisel, the engine will rev to a higher RPM, to a point. Correct or no? I guess I need to read up on diesels.