BX24 Engine Has "BX23" Label!
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crbr
Veteran Member
hill
Gold Member
I doubt it's anything to be concerned about since all of the tractors in the size group are BX23 of one kind or another except those sold with integral loader and backhoe.
So maybe the BX24 designation is like a "Limited" version of a car. Same car but with leather, seat heaters, and on and on kind of included features.
So maybe the BX24 designation is like a "Limited" version of a car. Same car but with leather, seat heaters, and on and on kind of included features.
NoviceguyInCT
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- BX24 TLB & old JD 400, JD H140
Volfandt
Veteran Member
Seems Kubota offered two variants of the 22/23 hp 3 cylinder diesel found in the BX 22/2200, BX23/2230 and BX24/2350 lines. The D902 and D905 engines. They are both basically the same internally with a few differences externally.
My 2004 BX23 has the D905 engine which is rated at a conservative 22hp.
Sometime during the last yr of the BX23/2230 series (2005), Kubota went to the D902 engine and this is the same engine, with one additional hp thats in the BX24/2350's.
From what I can tell, the major differences between the D905 and D902 is in the valve cover and different fuel injector pumps on each. This is probably where the additional hp is generated.
Long story short, I wouldn't sweat the engine being labled as a BX23, the BX23 had a good run with the main reported problem being that the air filter bracket would crack and they went to an entirely different air filter solution on the BX24/2250 series.
Theres quite a few BX22/2200's pileing on the hrs with the same basic engine, which in itself is a pretty good testimonial of how durable these engines are.
My 2004 BX23 has the D905 engine which is rated at a conservative 22hp.
Sometime during the last yr of the BX23/2230 series (2005), Kubota went to the D902 engine and this is the same engine, with one additional hp thats in the BX24/2350's.
From what I can tell, the major differences between the D905 and D902 is in the valve cover and different fuel injector pumps on each. This is probably where the additional hp is generated.
Long story short, I wouldn't sweat the engine being labled as a BX23, the BX23 had a good run with the main reported problem being that the air filter bracket would crack and they went to an entirely different air filter solution on the BX24/2250 series.
Theres quite a few BX22/2200's pileing on the hrs with the same basic engine, which in itself is a pretty good testimonial of how durable these engines are.
Volfandt said:
I have tried on a several occasions to find out more about the differences between the D905 and the D902 engines. The differences are slight, and Kubota is almost silent on the details. From what I gather, the greatest differences are overall weight and exterior size - the B902 is about 25% lighter and a bit more compact than the D905. This would fall in line with Kubota's ongoing efforts to cut the production costs for the popular BX units.
The most puzzling thing to understand is why Kubota would claim that the D902 (found in the BX24) is more powerful than the D905 (found in the BX23 and BX22), given that, according to Kubota, both engines have identical displacement specifications.
So let’s take a closer look at how the estimated HP was measured. Estimated HP is published at 2 different RPM levels for each engine. The HP for the D905 is available at 3600 RPM and 3000 RPM, while the HP for the D902 is available at 3600 RPM and 3200 RPM. Published HP at 3,600 RPM shows that both engines have identical power in all 3 HP classes ("Gross Intermittent HP", "Net Intermittent HP" and "Net Continuous HP"). However, differences occur when the HP of each engine is measured at the lower RPM level; at 3200 RPM the D902 "appears" to be slightly more powerful than the HP of the D905 which was measured at 3000 RPM. However, this "apparent" difference would seem to be an artifact of the differences in the RPM ranges employed rather than an "actual" HP difference.
It seems to me that Kubota's claim that the BX24 is more powerful than the BX23 or BX22 may be the result of an unfair comparison between the D902 and D905 engines. It is not entirely clear to me why Kubota would choose to advance this misleading claim. Might this be a simple oversight, or could this be a strategic marketing ploy to sell more BX24s?
I invite TBN members who who are more knowledgeable than me to shed light on this puzzling HP claim.
Volfandt
Veteran Member
great post lp333, this may open some otherwise closed doors to us.
I much more enjoy the "nut's & bolts" much better than the "spec's" anyday
In a past life I worked directly with sales and marketing and one of the main goals of a particular marketing division is to gain an edge (or advantage) over it's competition. Most times the resulting edge isn't an out and out misrepresentation, it's merely taking a different avenue to arrive at the same conclusion. The conclusion is probably not false, it's just measured or determined by a different formula at a different place. I used to call it imaginative fabrication
This is why I snicker at those that take the "spec's" as gospel and not use the "real world" application of a product as a better measureing stick.
Whats likely to be more accurate, the spec indicateing a 460lb lifting limit on the FEL or actually seeing and/or working said FEL easily with nearly 600lbs of material?
Theres just NO WAY a particular product in a specific class is going to be "that much" better than comparable competing models, the competition is just too tight to allow one model to "run away" with it all, with the loan exception like Kubota did when it "invented" the subcut line. Course it wasn't long for it's competiton to catchup.
Anyways, I do have a WSM on the D905 but not the D902 and it would be interesting for those of us to post various specs between 'em to see if we can figure out where that additional 1 hp comes from. Could be we could easily squeeze out alittle mo-power out of both with sacrifying durability
I'd really like to increase the GPM more in my BX23 but not at the cost of prematurely wearing out various hydraulic assemblies.
Course time will tell and in a tractor's time frame, it can take decades to get that "great" reputation.
I much more enjoy the "nut's & bolts" much better than the "spec's" anyday
In a past life I worked directly with sales and marketing and one of the main goals of a particular marketing division is to gain an edge (or advantage) over it's competition. Most times the resulting edge isn't an out and out misrepresentation, it's merely taking a different avenue to arrive at the same conclusion. The conclusion is probably not false, it's just measured or determined by a different formula at a different place. I used to call it imaginative fabrication
This is why I snicker at those that take the "spec's" as gospel and not use the "real world" application of a product as a better measureing stick.
Whats likely to be more accurate, the spec indicateing a 460lb lifting limit on the FEL or actually seeing and/or working said FEL easily with nearly 600lbs of material?
Theres just NO WAY a particular product in a specific class is going to be "that much" better than comparable competing models, the competition is just too tight to allow one model to "run away" with it all, with the loan exception like Kubota did when it "invented" the subcut line. Course it wasn't long for it's competiton to catchup.
Anyways, I do have a WSM on the D905 but not the D902 and it would be interesting for those of us to post various specs between 'em to see if we can figure out where that additional 1 hp comes from. Could be we could easily squeeze out alittle mo-power out of both with sacrifying durability
I'd really like to increase the GPM more in my BX23 but not at the cost of prematurely wearing out various hydraulic assemblies.
Sometimes this is not a bad thing. Kubota seems to have stepped up to correct the 1st release issues that plagued the new BX series and when I visit the various different dealers to check out all the brands out there, plastic (or composite) materials are integrated into even the premium large tractors as well as the CUTS & SCUTs. In some cases the engines have been scaled back from 4 to 3 cylinder and alot of users have commented on the 3 cylinder diesels being smoother and even more powerful, over a comparable 4 cylinder. Some say the composite "skins" of these new tractors take more abuse without showing the results better than metal, i.e. no pot marks and/or dents.
Course time will tell and in a tractor's time frame, it can take decades to get that "great" reputation.
lp333 said:
Power (HP) is equal to torque x engine speed. The two engines have the same output at 3600 RPM but one has lower power at 3000 RPM versus the other at 3200 RPM. Assuming the torque is the same (good assumption of engine displacement is the same), then the engine that is spec'd at 3200 RPM must have a greater output (HP) than the one spec'd at 3000 RPM.
Note also that it's really hard to compare the performance of two engines with data from only two speeds - usually, it helps greatly to have an output curve - HP versus RPM and Torque (ft-lb) versus engine speed. This is what most engine design engineers rely on to compare two engines.
Now, that being said, just because the two engines have the same displacement doesn't mean that they have the same performance. A number of other factors can impact output - piston stroke, piston weight, heat management, fuel injection method (direct or port), valve timing, valve diameter, ignition timing, air induction (naturally aspirated, or forced induction) etc.
Hence, just because the 905 and 902 have the same displacement doesn't mean that they'll have the same output.
Volfandt
Veteran Member
Good points.
We already know that both are approx the same displacement and have indirect fuel injection. We also know that they have different fuel injection pumps and that the D902 weighs in less than the D905.
It would be interesting to see if the internals (pistons, rod's, crank etc), have the same part #'s between 'em.
The D905 has a bore & stroke of: 2.83" X 2.90", 54.8 cu in.
Maximum torque is rated @ 40.5 ft lbs between 2200 & 2600 rpm.
Engine gross power is rated at 22hp but the WSM doesn't indicate at what rpm gross hp is achieved.
The WSM indicate's that the Rated Revolution is 3200 rpm but it is unclear if this is where the rated hp is measured.
Going on lp333's posted numbers on the rated outputs at 3000, 3200 & 3600 rpm of both engines, it would almost seem to point to the D905 as being close to or even having the same power output as the D902. We would either need to see a full power curve chart per x703jko's suggestion or see what the D905 is rated at @3200 rpm. (or what the D902 is rated @ 3000 rpm).
We already know that both are approx the same displacement and have indirect fuel injection. We also know that they have different fuel injection pumps and that the D902 weighs in less than the D905.
It would be interesting to see if the internals (pistons, rod's, crank etc), have the same part #'s between 'em.
The D905 has a bore & stroke of: 2.83" X 2.90", 54.8 cu in.
Maximum torque is rated @ 40.5 ft lbs between 2200 & 2600 rpm.
Engine gross power is rated at 22hp but the WSM doesn't indicate at what rpm gross hp is achieved.
The WSM indicate's that the Rated Revolution is 3200 rpm but it is unclear if this is where the rated hp is measured.
Going on lp333's posted numbers on the rated outputs at 3000, 3200 & 3600 rpm of both engines, it would almost seem to point to the D905 as being close to or even having the same power output as the D902. We would either need to see a full power curve chart per x703jko's suggestion or see what the D905 is rated at @3200 rpm. (or what the D902 is rated @ 3000 rpm).
