Varying Engine Specs

NetMagi

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Dec 30, 2014
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I'm pulling my hair out over here. I'm putting in a semi-permanent generator at my house (inside a detached shed), and the engine is a Kubota D1005.

The genset manufacturer, of course, overrated the output. I knew this going into it, and ignored their max output rating, but figured the continuous was probably true"ish"

I started doing the math myself to calculate the "real" capability, and this is where the hair pulling begins.

It's an 1800rpm genset, so if you go to Kubota's published specs, the stand-by (max) output of the D1005 is 9.8kW @ 1800rpm. The gen head is rated at 79.1% efficient, so without subtracting the loss from the fan, water pump, alternator, etc., that's a max output (at a power factor of 1) of 7,751 watts, or about 32.3A @ 240v.

So, I look at the block, and the ACTUAL STICKER on the Kubota block reads:

Model: D1005-BG-EF02
Family: EKBXL01.0BCC
Power: 10.8kW/1800rpm

The sticker includes the date: 2014/07

Ahhhm. . . what?? 10.8kW. . what happened to 9.8kW? Also, what the heck is a D1005-BG-EF02, specifically, the "BG-EF02" part. This doesn't match any of the model #s on Kubota's sites. For a D1005 @1800rpm, they list "D1005-E3BG", and rates it at 9.8kW. Kubota's model # guide refers to "BG" as "old generator spec", but there's no specs or a model list.

I'm wondering if maybe BG-EF02 is a different spec of this motor with the "fuel turned up" from the factory. . . . . or is the 10.8kW printed right on the block just BS?

If you google, "D1005-BG-EF02", the only thing that turns up is EPA testing results, but they do have an exact match for the Model and Family #'s above, and the output power is rounded in the EPA docs to "11 kW".

Anybody familiar with these varying specs from Kubota? The gen head is legitimately rated to supply up to 10.5kW (with enough HP behind it), so if the motor is really putting out 10.8kW, that's closer to ~8500 watts of usable power from this set.
 
Last edited:

olthumpa

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If you are not already confused::eek:

[SIZE=-1]horsepower[/SIZE] [SIZE=-1]42.44[/SIZE] [SIZE=-1]Btu/min[/SIZE]
[SIZE=-1]horsepower[/SIZE] [SIZE=-1]33000[/SIZE] [SIZE=-1]foot-lbs/min[/SIZE] [SIZE=-1]
horsepower[/SIZE]
[SIZE=-1]550[/SIZE] [SIZE=-1]foot-lbs/sec[/SIZE]
[SIZE=-1]horsepower (metric)[/SIZE] [SIZE=-1]0.9863[/SIZE] [SIZE=-1]horsepower[/SIZE] [SIZE=-1]
horsepower[/SIZE]
[SIZE=-1]10.68[/SIZE] [SIZE=-1]kg-calories/min[/SIZE]
[SIZE=-1]horsepower[/SIZE] [SIZE=-1]0.7457[/SIZE] [SIZE=-1]kilowatts[/SIZE]
[SIZE=-1]horsepower (boiler)[/SIZE] [SIZE=-1]33479[/SIZE] [SIZE=-1]Btu/hr[/SIZE] [SIZE=-1]
horsepower (boiler)[/SIZE]
[SIZE=-1]9809.5[/SIZE] [SIZE=-1]watts[/SIZE] [SIZE=-1]
horsepower (metric)[/SIZE]
[SIZE=-1]735.4988[/SIZE] [SIZE=-1]watts[/SIZE] [SIZE=-1]
horsepower (electric)[/SIZE]
[SIZE=-1]746[/SIZE] [SIZE=-1]watts[/SIZE] [SIZE=-1]
horsepower[/SIZE]
[SIZE=-1]see tables[/SIZE] [SIZE=-1]cc and cu.in. (approx)[/SIZE]
[SIZE=-1]horsepower (UK)[/SIZE] [SIZE=-1]745.7[/SIZE] [SIZE=-1]watts[/SIZE] [SIZE=-1]
horsepower (water)[/SIZE]
[SIZE=-1]746.043[/SIZE] [SIZE=-1]watts[/SIZE]
 

NetMagi

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BX25D (sold), L2501HST w/BH77 Backhoe
Dec 30, 2014
132
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Pennsylvania
Hi guys,

I appreciate the feedback, but I'm good with the conversions.

I know I was long-winded with mixing in talking about how many usable watts of electricity I'd have, but my main concern is around trying to determine the actual amt. of crank power I can expect to get out of this specific model "D1005-BG-EF02" motor. Specs for the D1005 from Kubota's datasheets say 9.8kW, but they do mention that they can vary based on options.

The specific "D1005-BG-EF02" I actually have sitting in front of me is labeled as being able to produce 10.8kW of power at the crank.

Here's the label:



If this variant of the D1005 really does produce 10.8kW of crank power, I wonder what the difference is between this variant and the "general" D1005 BG variant.

-Rich H.
 

NetMagi

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Dec 30, 2014
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Got to thinking maybe the Emissions stickers use some different measurement std. from the EPA, so I went and looked at the sticker on the D902 in my BX25D to compare. Here it is:



Shows 16.1kW @3200rpm, which matches the general Kubota spec sheet exactly.
 

olthumpa

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May 25, 2011
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On gasser it is easier to do but can also easily be don at the factory, (more difficult by your self), on a diesel.

Change the crank, cam, timing, or air and fuel amounts. Changing these will change the amount of hp.

The same engine for a tractor is designed to operate at a variety of rpm's. An engine that is designed for a constant speed such as a generator is optimized for a specific rpm and produces more hp. Kinda over simplified. :)

Tractor -Injector Timing = 16.5 DEG BTDC
Generator -Injector Timing = 19 DEG BTDC
 

NetMagi

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BX25D (sold), L2501HST w/BH77 Backhoe
Dec 30, 2014
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On gasser it is easier to do but can also easily be don at the factory, (more difficult by your self), on a diesel.

Change the crank, cam, timing, or air and fuel amounts. Changing these will change the amount of hp.

The same engine for a tractor is designed to operate at a variety of rpm's. An engine that is designed for a constant speed such as a generator is optimized for a specific rpm and produces more hp. Kinda over simplified. :)

Tractor -Injector Timing = 16.5 DEG BTDC
Generator -Injector Timing = 19 DEG BTDC
Yeh, I had also noticed the inj. timing difference (you reversed them in your reply, but the point remains). What's unusual though is that Kubota does supply a specific power rating for the 1800rpm BG model, and it doesn't match this label.

I also submitted a query to Kubota regarding this yesterday, but haven't heard back yet.

-Rich H.
 

North Idaho Wolfman

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If you are not already confused::eek:

[SIZE=-1]horsepower[/SIZE] [SIZE=-1]42.44[/SIZE] [SIZE=-1]Btu/min[/SIZE]
[SIZE=-1]horsepower[/SIZE] [SIZE=-1]33000[/SIZE] [SIZE=-1]foot-lbs/min[/SIZE] [SIZE=-1]
horsepower[/SIZE]
[SIZE=-1]550[/SIZE] [SIZE=-1]foot-lbs/sec[/SIZE]
[SIZE=-1]horsepower (metric)[/SIZE] [SIZE=-1]0.9863[/SIZE] [SIZE=-1]horsepower[/SIZE] [SIZE=-1]
horsepower[/SIZE]
[SIZE=-1]10.68[/SIZE] [SIZE=-1]kg-calories/min[/SIZE]
[SIZE=-1]horsepower[/SIZE] [SIZE=-1]0.7457[/SIZE] [SIZE=-1]kilowatts[/SIZE]
[SIZE=-1]horsepower (boiler)[/SIZE] [SIZE=-1]33479[/SIZE] [SIZE=-1]Btu/hr[/SIZE] [SIZE=-1]
horsepower (boiler)[/SIZE]
[SIZE=-1]9809.5[/SIZE] [SIZE=-1]watts[/SIZE] [SIZE=-1]
horsepower (metric)[/SIZE]
[SIZE=-1]735.4988[/SIZE] [SIZE=-1]watts[/SIZE] [SIZE=-1]
horsepower (electric)[/SIZE]
[SIZE=-1]746[/SIZE] [SIZE=-1]watts[/SIZE] [SIZE=-1]
horsepower[/SIZE]
[SIZE=-1]see tables[/SIZE] [SIZE=-1]cc and cu.in. (approx)[/SIZE]
[SIZE=-1]horsepower (UK)[/SIZE] [SIZE=-1]745.7[/SIZE] [SIZE=-1]watts[/SIZE] [SIZE=-1]
horsepower (water)[/SIZE]
[SIZE=-1]746.043[/SIZE] [SIZE=-1]watts[/SIZE]
You forgot one!
1 horsepower = 1 draft horse :p
 

olthumpa

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L275
May 25, 2011
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You forgot one!
1 horsepower = 1 draft horse :p
Which one? :eek:

Ardennais
Ariegeois
Bashkir
Belgium Draft
Boulannais
Breton
Clydesdale
Fjord
Haflinger
Irish Draft
Italian Heavy Draft
Jutland
Noriker
Norman Cob
North Swedish
Percheron
Schleswig Draft Horse
Shire
South German Heavy Horse
Suffolk Punch
Vladimir Heavy Draft
etc.
etc.

Now you are just confusing things. :p ;) :D
 

NetMagi

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Equipment
BX25D (sold), L2501HST w/BH77 Backhoe
Dec 30, 2014
132
94
28
Pennsylvania
I'm starting to think there really are at least two different models/spec's for the 1800rpm version of the D1005.

I've found numerous reputable manufacturers with 8.5kW generators for both land and sea applications that leverage some variant of the Kubota D1005.

This example is particularly interesting:

http://www.phasormarine.com/k3-7-0kw.htm

vs.

http://www.phasormarine.com/k3-8-5kw.htm

The specs are identical between the models with one exception:

The 7kW unit lists "D1005-BG" for the engine model, and the 8.5kW unit lists "D1005-BGE".

-Rich H.