16 more HP from the same size engine?

[bilrus61]

In the JD 4000 series the 4720 has 56 PTO hp out of the same sized turbocharged engine as the 4320 that has "only" 40 PTO hp. Both engines are turbocharged. The Kubota L5040 has the same displacement and its turbocharged engine puts out 44 PTO hp. I know you can "turn it up" but that seems like a huge jump in horsepower. Nobody else seems to be able to get that kind of horsepower from a engine of that size. How do they get that kind of boost?

 

[RoyJackson]

Just because the engines are the same displacement doesn't mean they're the same engine (although I'd guess they are the same basic engine).
The turbo will add some power. A higher rated turbocharger, the injection pump, camming and other differences (bigger valves, for example) between the engines can account for the differences in horsepower ratings.

Even the testing method can make a difference when it comes to "advertised" horsepower.

 

[radman1]

That practice is very common in the industry. Larger ag tractors may have 50 hp difference between models in the same series using the same engine. On the CUTs it maybe in part due to +/- a turbocharger and computer changes. On most ag tractors it may be an injector difference but usually just a computer setting difference. A dealer could change the computer settings but if discovered, corporate would be extremely unhappy to say the least.

 

[CurlyDave]

20+ years ago I worked on a project in the diesel truck and engine industry.

One of the most interesting things I discovered was that the same engine could be produced in a wide range of horsepower ratings.

For instance, the 855 cubic inch Cummins engine was sold to fleets with a rating in the 180-200 hp class. Increase the fuel injector size and that same engine would put out 350-400 hp, which is what a lot of owner-operators bought. The penalty was a decrease in life and a decrease in fuel economy.

Take that same engine and put in some really big fuel injectors and the military would buy it as a 1000 hp powerplant for Armored Personnel Carriers. The life decreased to about 5000 miles, and fuel "economy" wasn't on the priority list at all.

 

[MikeInEburg]

A friend works for Mack Truck and told me how they control engine horsepower thru software. A truck owner can purchase an engine HP upgrade and the only change is software. HOWEVER, before they'll do an HP upgrade, they first verify that the transmission is capable of handling the increased power. Something for tractor owners thinking these thoughts to consider as well.
Mike

 

[Nuru]

A friend works for Mack Truck and told me how they control engine horsepower thru software. A truck owner can purchase an engine HP upgrade and the only change is software. HOWEVER, before they'll do an HP upgrade, they first verify that the transmission is capable of handling the increased power. Something for tractor owners thinking these thoughts to consider as well.
Mike

Good point, as yes in some cases it is a software mod.

 

[wolc123]

So I guess that means if you want to keep your tractor a long time, you might be better off with the 4120 rather than the 4720. That would also let you keep lots of your money at purchase, and save even more money on fuel. I have had a 4120 for 5 years and never felt a need for more hp. I can run a 6 ft bush hog all day long on 6 gallons of diesel (just did today in fact) and the tractor has never given me a problem.

 

[jenkinsph]

So I guess that means if you want to keep your tractor a long time, you might be better off with the 4120 rather than the 4720. That would also let you keep lots of your money at purchase, and save even more money on fuel. I have had a 4120 for 5 years and never felt a need for more hp. I can run a 6 ft bush hog all day long on 6 gallons of diesel (just did today in fact) and the tractor has never given me a problem.

When you consider that the 4120 through the 4720 are all using a 149 cu in engine with a turbo none of these are working very hard. I think your thoughts are correct to a lesser degree than you may think. When you take a 149 ci motor and start trying to get 100 hp or higher from it it will indeed shorten the life. If you run a 4120 at full output (43hp)and a 4720 at 2/3 of its output for 44hp I don't think you would see much difference in engine life. The difference between the 43hp engine and the 66hp in performance is substancial though. I have the 43hp Yanmar non turbo motor in my 110 and the 60hp turbo in the 4520 and there is a huge diference in the get up and go.

 

[RollingsFarms]

the 179 ci motor in the 5D & 5E series is an even greater difference then that. in it's lowest setting it puts out 45hp but they crank it up to 74hp. heck, I think it was Montana or some tractor company that was using this same engine in their biggest tractor and getting 80 or 88hp(can't remember exact number) from it! my 5203 uses the same engine as the 5D and 5E series but it's only putting out 56hp with a turbo. funny thing is, I can see the turbo with my own eyes under the hood, touch it, stare at it, take a pic of it, but I can't hear it at all. is it that way with the 4020 series too?

 

[sunnyside360]

......... my 5203 uses the same engine as the 5D and 5E series but it's only putting out 56hp with a turbo. funny thing is, I can see the turbo with my own eyes under the hood, touch it, stare at it, take a pic of it, but I can't hear it at all. is it that way with the 4020 series too?

I can't hear the turbo in either my 4320 or 3720 tractors. I have no trouble hearing the turbo on my Kubota M8200 but it uses about twice as much fuel as the two Deeres.

 

[wolc123]

I can hear the turbo plain as day on my 4120 and so can anyone else who knows what one sounds like. I like the sound. My nieghbor has a 4720 and it's sound is virtually identical. I have never listened to a 4320 or 4520 but I cant imagine them sounding any different. You can really hear it wind up when you pump the foot throttle. One thing that is distinctive on these engines is that they are significantly louder at idle than comparable hp naturally aspirated Yanmars used on smaller series, but not much if any louder at PTO rpm where most work is actually done.

 

[RollingsFarms]

I can hear the turbo plain as day on my 4120 and so can anyone else who knows what one sounds like. I like the sound. My nieghbor has a 4720 and it's sound is virtually identical. I have never listened to a 4320 or 4520 but I cant imagine them sounding any different. You can really hear it wind up when you pump the foot throttle. One thing that is distinctive on these engines is that they are significantly louder at idle than comparable hp naturally aspirated Yanmars used on smaller series, but not much if any louder at PTO rpm where most work is actually done.

i know how they sound, i guess that's why i'm wondering why i'm not hearing mine. i can hear them plain as day on larger tractors(100hp +). even at idle you can hear them. i've listened to all 4020 series tractors, both in person, and videos on youtube and can't hear it at all. i've heard the turbo on 5025(now the 5M series) pretty good, although not as noticible as on those 100+ hp tractors i mentioned earlier. even tractors comparable in size to mine (kubota M5040/6040 for example) isn't noticible.

 

[usmc5595]

i know how they sound, i guess that's why i'm wondering why i'm not hearing mine. i can hear them plain as day on larger tractors(100hp +). even at idle you can hear them. i've listened to all 4020 series tractors, both in person, and videos on youtube and can't hear it at all. i've heard the turbo on 5025(now the 5M series) pretty good, although not as noticible as on those 100+ hp tractors i mentioned earlier. even tractors comparable in size to mine (kubota M5040/6040 for example) isn't noticible.

I have a 5103 and do not hear mine either. I also have a 5.9 cummins turbo diesel, I definitely hear it. However cummins/dodge goes to great lengths to make it not hearable. Maybe that is what happens w/ JD. My cummins had baffles and air veins inside the air tubs to make it quiet, but it also restricts flow and power.

I am gong to check mine out, I don't want to turn the pumps up or change injectors but it would be nice to free up some HP and left it run better and be even more fuel efficient. Any ideas on how to do that?

 

[RollingsFarms]

I have a 5103 and do not hear mine either. I also have a 5.9 cummins turbo diesel, I definitely hear it. However cummins/dodge goes to great lengths to make it not hearable. Maybe that is what happens w/ JD. My cummins had baffles and air veins inside the air tubs to make it quiet, but it also restricts flow and power.

I am gong to check mine out, I don't want to turn the pumps up or change injectors but it would be nice to free up some HP and left it run better and be even more fuel efficient. Any ideas on how to do that?

i didn't know that about the 5.9. i usually hear the turbo very well on diesel pickups, even the new ones that are supposed to be so quiet.

 

[Reg]

Same engine block (base casting) does not equate to "Same Engine".

There was and still is a VAST difference between the various incarnations of the Chev 350 "small block".

LOTS of alternatives with heads, cams, carburation, ignition, fuel injection (& programming/mapping), exhausts, turbos, etc.

 

[SpudHauler]

Take it to the extreme. Drag racers take an everyday 350 chevy engine producing around 250 hp and turn them into 1000 hp giant killers.

But: They rebuild them every weekend.

As stated earlier, more hp, more wear, more maintenance, more cost, less hrs between rebuilds.

Find the happy medium and you have a winner!

 

[MBDiagMan]

The dynamics of a diesel engine are quite different than a gas engine. A gas engine draws air AND fuel into the cylinders while a diesel only draws air and then at the critical moment, fuel is injected. You can make more power in most ANY diesel by injecting MORE fuel. The trick is that the more fuel you inject, the more air must be drawn in for proper stoichiometrics(proper flame and combustion temperature.)

In the old days (of which I am plenty old enough to have experience with) the truckers would have people "turn up" their engines which basically meant more fuel injected. This made lots more power but caused EXTREMELY accelerated engine wear. This was done in a black market sort of way because the truck didn't belong to the driver, but the driver got paid by the mile.

SO, with the same size engine, the turbo boost can be increased with a proper proportional increase of fuel being injected without causing excessive combustion chamber heat. It will put more stress on the bottom end of the engine, but when done by the factory, their testing will indicate how much the bottom end can take without undue stress.

 

[om21braz]

Back to the original question regarding the Deere engines, if my memory serves me correctly, at least some of the difference in power comes from boost. I believe the 4120 should max. out @ 7 psi where the 4720 should go 14psi before opening the wastegate. Others here have previously noted the turbo part# being the same for 4120/4320 and a different part for 4520/4720.

 

[MBDiagMan]

I have lots of diesel engine experience, but not specifically with the engine in question. Depending on the particular injection/turbo system employed on these engines, changing the turbo alone might very well not give you the power increase you expect.

As I tried to explain, increasing the FUEL is what adds the power. To increase fuel delivery without toasting the engine, you also must add the correct amount of air, in this case in the form of boost.

It's also possible that the turbo's might even be the same, but a wastegate is used and that's where the change would be made.

You need someone with very good familiarity with this engine family to give you the EXACT correct information for this modification or you could be asking for at best a disappointment and at worst a toasted engine.

Hope this helps and keep us informed. This is a very interesting subject.

 

[Dargo]

Interesting. I looked up my JD engine, the John Deere PowerTech 4045 engine. In a 5425 that engine puts out 81 engine hp. Move all the way up to the JD 5105 (newer model and model numbers) and it has the same John Deere PowerTech 4045 engine but puts out 105 engine hp. That's 23 more hp from the same engine from the factory. I say "from the factory" because there's all sorts of hp you can get out of a modded diesel which may, or may not, be reliable and durable.

I suppose it sort of makes me feel good that my tractor, a JD 5525, is sort of in the middle and puts out 91 engine hp. Apparently JD feels that the same engine will take at least 14 more hp. Besides, I honestly didn't know how many tractors JD puts their PowerTech 4045 engine in. Maybe it's one of their good workhorse engines? (with fingers crossed). Anyway, with that 4045 engine the factory power output ranges by 23 hp.