Same Engine, Different Horsepower

[J W Bishop]

I致e been looking at some compact tractors and I知 confused about something. Spec sheets show 3 different HP ratings (40, 45, 50) but all 3 tractors have same engine, same frame, and same weight. What makes the difference in HP?

 

[nards444]

I致e been looking at some compact tractors and I知 confused about something. Spec sheets show 3 different HP ratings (40, 45, 50) but all 3 tractors have same engine, same frame, and same weight. What makes the difference in HP?

same size doesnt always mean same engine. To answer your question, programming, fuel delivery, gearing, many things

 

[ptsg]

I'll give you the case for the 15 Series on a Branson.

There is the 3015 (with the Kukje/Cummins A1700 derated at 30HP, then there is the 3515 with the same A1700 engine with 35 HP and last there is the 4015 with the yet again A1700 engine but with turbo. All mechanical engines, not computer used.

Different fuel setup and adding a turbo will cause those changes on the same engine.

 

[shooterdon]

The LS 4100 series engines are identical...or so I am told be the dealer. Different HP is due to computer program. He can make my 40 hp into a 50 hp but LS monitors his computer and they will freak if he does that. I would not do it unless I find I need more HP but so far so good. I would wait until the warranty is over as well.

 

[nards444]

The LS 4100 series engines are identical...or so I am told be the dealer. Different HP is due to computer program. He can make my 40 hp into a 50 hp but LS monitors his computer and they will freak if he does that. I would not do it unless I find I need more HP but so far so good. I would wait until the warranty is over as well.

most modern engines are detuned in most things. For one doesnt stress the engine out, 2 allows the manufacture to say next year "new" upgraded engine with 10% more HP

 

[SSdoxie]

Quite common with today's electronic injection to have various HP ratings of the same engine, no internal differences. The ECM programming changes fuel injection timing, volume, & pressure to alter the available torque at RPM. Torques X RPM divided by 5252 = rated HP.

 

[ericm979]

With diesels, more fuel == more power, up to a point. It's not like gas engines where there's a narrow range of fuel:air ratios that are effective.

From a manufacturing and marketing standpoint it makes sense to have different tractor models that use the same engine with different injection tuning to get different power levels and thus model differentiation. It's fewer engines to make and keep in stock. For example the Kubota L3301 and 3901 are the same tractor with the ECU turned up on the 3901, for whick Kubota charges about $2000. I think there's one other small difference in the PTO.

It can be done on mechanical injection too. The Branson 3725 and 4225 are the same tractor with the same engine model number, but one has 5hp more. I asked my dealer and they said the difference is the fuel injectors. I can see how on a mechanical FI system the injector size would limit the amount of fuel.

 

[finn1]

Back in the eighties and before, manufacturers would design and produce engines in small displacement. Off the top of my head, International made a 155 and 179 three cylinder engine, 206, 239, and 268 , plus a 239 turbo engine, and 310, 358, 402, and 358 turbo six cylinder engines, all the same family, and all made on the same line.

Deere had a similar lineup.

The complexity and logistics were mind boggling, and very expensive.

Today, manufacturers understand the cost of this complexity, and, with modern electronic common rail fuel systems, can offer one basic bore and stroke in three, four, and six cylinder versions, and cover the same power range.

Remember, the manufacturer is selling power. Without the different displacements, it was easy to buy the lowest power engine, and turn the pump up, cutting the manufacturers profit.

With modern electronics, it’s not so easy.

Remember, although we all like cheap tractors, the manufacturer needs profit to develop new products and keep investors happy.

Without profit, it’s a race to the bottom.

 

[ovrszd]

The road grader I run even has different HP output depending on what gear it's in. The lower the gear, the lower the HP. The higher the gear, the higher the HP. Ranging 175Hp thru 255HP in 8 gears.

 

[Industrial Toys]

When we bought our JD 6200, there was a 6300 and 6400, all identical except for HP and Injector pumps. I figured buying the lowest was the BEST deal and meant buying a tractor and drivetrain that was heavier than required for the given HP. Rather then the other way around.