Posted by DJ on August 12, 2003, 9:57 pm
> Hey, all!
> I have it in mind to build a power center from an old Kubota 2-cylinder
> engine. It originally was on a small lawn tractor, or so the specs say.
Remember that.
> I finally found a place to get a shop/maintenance manual, which
> dictates that the oil should be changed after less than 100 hours. Not
> after rebuild, but every time!
Now, think about it. 100hrs of running time. How long does it take to
cut your lawn? How often do you cut your lawn? I'm guessing four
hours, tops, maybe fifty times a year if you live in the south? That
makes 100hrs about twice a year, doesn't it?
Where I'm going with this is that in the maintenance field (I'm a
journeyman millwright/maintenance mechanic by trade) is that engine
time and calendar time have to meet somewhere. One of the biggest
problems requiring oil changes is water contamination. Engines get
hot, then they cool, condensation forms, the oil turns into a
milkshake.
The maintenance schedule has to prevent that by changing the oil
before that can happen to that little lawn tractor that you're running
for three or four hours once a week ;-).
> The plan is for the engine to run basically 24/7, except for basic
> maintenance (including oil). Stop and change oil/filter every 3 days??
> The question for the group is: why would Kubota specify such a short
> interval, when diesel engines for cars and trucks can go
> months/thousands of miles between?
Because you're not using it for what it was designed for; if you
were, you would need to follow that schedule or something like it.
> Is it a matter of what materials the rings,cylinder walls, bearings,
> etc. are made of that they won't last as long, or that Kubota expects
> this model engine to be forever in a dusty environment and figured
> intervals accordingly?
Nah. If it was engine wear, you'd be doing rings and pistons every
year. Kubota has a better name than that, as far as I know.
> Needless to say, it won't be in a dirty environment when I get through
> with it!
Well, if it were me, and this offers no guarantee nor warranty nor any
other contract, just friendly opinion, I would put synthetic oil in
it, a top grade filter on the line, and a magnetic plug in the drain.
Change it the first time after 100 hrs. Inspect everything,
especially the magnet. You're looking for dark, smelly oil, or oil
that looks like chocolate milk, and tiny metal filings stuck to the
magnet.
Engines don't care how often you change the oil: they just care how
well the oil flows, and how dirty/broken down/contaminated it is. If
the filter is clean, and the oil is not burned or milky, and nothing
is grinding metal into the oil pan, it doesn't necessarily need to be
changed.
In industry, you *CHECK* the oil regularly, and you CHANGE the oil
when it needs it, regardless of running hours.
DJ
Posted by Dean Dardwin on August 13, 2003, 8:14 am
You were doing fine until your reached your conclusion.
Synthetic oil is a great recommendation.
Oil is supposed to get dark. That's the detergent qualities keeping all
the combustion by-products in suspension so they will be drained with
the oil. This helps prevent the formation of sludge.
Oil never "breaks down". It becomes contaminated. Besides water
accumulation, acids form. They eat bearings.
Oil gets changed per the engine manufacturer's recommendation
religiously in any "industry" that values its equipment.
Dean
DJ wrote:
>
>>Hey, all!
>> I have it in mind to build a power center from an old Kubota 2-cylinder
>>engine. It originally was on a small lawn tractor, or so the specs say.
>
>
> Remember that.
>
>
>> I finally found a place to get a shop/maintenance manual, which
>>dictates that the oil should be changed after less than 100 hours. Not
>>after rebuild, but every time!
>
>
> Now, think about it. 100hrs of running time. How long does it take to
> cut your lawn? How often do you cut your lawn? I'm guessing four
> hours, tops, maybe fifty times a year if you live in the south? That
> makes 100hrs about twice a year, doesn't it?
>
> Where I'm going with this is that in the maintenance field (I'm a
> journeyman millwright/maintenance mechanic by trade) is that engine
> time and calendar time have to meet somewhere. One of the biggest
> problems requiring oil changes is water contamination. Engines get
> hot, then they cool, condensation forms, the oil turns into a
> milkshake.
> The maintenance schedule has to prevent that by changing the oil
> before that can happen to that little lawn tractor that you're running
> for three or four hours once a week ;-).
>
>
>> The plan is for the engine to run basically 24/7, except for basic
>>maintenance (including oil). Stop and change oil/filter every 3 days??
>> The question for the group is: why would Kubota specify such a short
>>interval, when diesel engines for cars and trucks can go
>>months/thousands of miles between?
>
>
> Because you're not using it for what it was designed for; if you
> were, you would need to follow that schedule or something like it.
>
>
>> Is it a matter of what materials the rings,cylinder walls, bearings,
>>etc. are made of that they won't last as long, or that Kubota expects
>>this model engine to be forever in a dusty environment and figured
>>intervals accordingly?
>
>
> Nah. If it was engine wear, you'd be doing rings and pistons every
> year. Kubota has a better name than that, as far as I know.
>
>
>> Needless to say, it won't be in a dirty environment when I get through
>>with it!
>
>
> Well, if it were me, and this offers no guarantee nor warranty nor any
> other contract, just friendly opinion, I would put synthetic oil in
> it, a top grade filter on the line, and a magnetic plug in the drain.
> Change it the first time after 100 hrs. Inspect everything,
> especially the magnet. You're looking for dark, smelly oil, or oil
> that looks like chocolate milk, and tiny metal filings stuck to the
> magnet.
> Engines don't care how often you change the oil: they just care how
> well the oil flows, and how dirty/broken down/contaminated it is. If
> the filter is clean, and the oil is not burned or milky, and nothing
> is grinding metal into the oil pan, it doesn't necessarily need to be
> changed.
> In industry, you *CHECK* the oil regularly, and you CHANGE the oil
> when it needs it, regardless of running hours.
>
> DJ
Posted by Chris Hill on August 13, 2003, 11:13 am
wrote:
>You were doing fine until your reached your conclusion.
>Synthetic oil is a great recommendation.
>Oil is supposed to get dark. That's the detergent qualities keeping all
>the combustion by-products in suspension so they will be drained with
>the oil. This helps prevent the formation of sludge.
>Oil never "breaks down". It becomes contaminated. Besides water
>accumulation, acids form. They eat bearings.
Oil breaks down too. Heat and wear turns the long chain molecules
into shorter ones, and they don't lubricate as well.
Posted by DJ on August 13, 2003, 12:55 pm
> You were doing fine until your reached your conclusion.
>
> Synthetic oil is a great recommendation.
>
> Oil is supposed to get dark. That's the detergent qualities keeping all
> the combustion by-products in suspension so they will be drained with
> the oil. This helps prevent the formation of sludge.
Oh, and one little afternote:
Alot of pumps and such, I'm thinking of a particular low pressure
steam boiler pump who's internal guts are etched into my mind ;-),
often specify *non-detergent* oil.
DJ
Posted by DJ on August 13, 2003, 9:37 pm
> The subject is diesel engines, remember? No one gives a rat's ass about
> steam boiler pumps.
Ya know, Dean, you're not a very nice guy. Here I was, trying to add a
bit of info I gathered over the years in my career as an industrial
mechanic, and you've gotten all cranky.
Certainly, you must be right. All machines are different. Nobody
cares.
Bye.
DJ
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> I have it in mind to build a power center from an old Kubota 2-cylinder
> engine. It originally was on a small lawn tractor, or so the specs say.