loewent via CarKB.com wrote:
> Jim,
>
> Not trying to jack this thread. But I have a question.
>
> Why does automotive engine usage get measured in miles/kms and any other
> heavy duty application get measured in hours?
>
> Wouldn't these engines from Japan have crazy high hours?
>
> I was speaking with a farmer the other day, and he shed some good light on
> the whole oil change thing.... He said John Deere recommends an oil change
> every 300-400 hours.
>
> If I translate that length of time into KMs in my car, assuming my average
> speed is around 50km/h, (I do alot of highway miles) that would mean that 300
> hours is 15000kms? For the record, I change every 5000kms. But why the
> discrepancy?
>
> I buy heavy duty diesel engines for a living. I don't maintain them for a
> living though... otherwise I would know Cummins' intervals for oil changes.
> But I do happen to know on the design side that oil filtration is really no
> different on these heavy duty applications than on the average consumer
> vehicle.
>
> Comments?

very good question! to skip forward a bit, there's quite a bit of
movement in the industry towards pushing out oil change intervals.
there's two main methods - one is using the ecu to log usage and
electronically compare that with a table of oil conditions. the other is
measuring dielectric constant and mapping that in much the same way.
the expensive option is actual spark spectroscopy analysis like they use
in f1, but i'm not aware of that being used in production vehicles.

biggest reason for hour-based changes vs mileage is that with a lot of
diesels, [generators, etc.] there /are/ no miles to log! farm gear
doesn't cover a lot of mileage either.

regarding discrepancy, big commercial diesels tend to have a much more
regular life than the average passenger car. not only do diesels wear
less on cold start [diesel wetting a cylinder wall is a lubricant, not a
dilutant like gasoline], they tend to have a lot fewer cold starts too.
a lot of trucks run for days on end, marine diesels for months on end.
this means the oil has less crud in it from the cold start process
which helps. then there's filtration. a lot of big diesels have two
filters - one is full flow, the other is bypass. the bypass filter
pulls out all the fine stuff the full flow filter doesn't, and this
keeps the oil in pretty good shape. a lot of commercial fleets are also
supported by oil analysis and usage logging. a vehicle used on a
regular route can have its oil change strategy "tuned" very accurately.
hardly any passenger cars do this, so manufacturers are really trying
to cover hugely different usage patters with their recommended service
intervals.

but the bottom line on all this though is what the market supports.
even my old 89 civic has a 7500 mile change interval. yet who here
waits that long? the later civics have 10k as their interval - at
30mph, that's 333 hours, not far off john deere's diesel spec. again,
there's a lot of resistance among american consumers about extended
change intervals with people routinely ignoring the onboard diagnostics
and getting oil changed 2 or even 3 times before the oil service
notification comes on. i don't see us embracing much beyond 10k unless
there's a massive public education campaign, but that's against the
interests of the oil industry, so that ain't going to happen! otoh, i
hear that the europeans are very keen on long change intervals and for
pushing it out as far as possible with up to 30k on some of the euro
cars. of course, improved lubricants play a significant role in that too.

>
> t
>
> jim beam wrote:
>>> thanks jim,
>>>
>> [quoted text clipped - 3 lines]
>>> also, is this industry legit? as in, are the mileages they quote for
>>> real or is it just B.S.? would i be better off going to the junk yard?
>> no, it's legit. mileages should be about right - other markets,
>> particularly japan, do much lower mileage than us. that's why i'd only
>> buy a domestic motor in emergency - /much/ higher mileage. but that
>> said, there's no reason a d15 can't do 300k miles if it's not been
>> cracked and has had the oil changed regularly.
>>
>> i'm not endorsing any of the following:
>> http://www.sunrisejdmmotors.com/
>> http://www.nippon-motors.com/honda.htm
>> http://www.naganojapanese.com/
>>
>> there are a bunch of others if you google.
>>
>> good luck!
>>
>>> thanks again (exciting saturday, right?).
>> you're not going anywhere with that motor!
>>
>>>>> i've done some looking online and it's difficult to discern what's what
>>>>> and if a given website is legitimate. that's the biggest difficulty.
>> [quoted text clipped - 50 lines]
>>>>>> a number of possible causes, all of which are cheaper and less
>>>>>> troublesome than replacing the whole unit.
>

 

loewent via CarKB.com wrote:
> Jim,
>
> Not trying to jack this thread. But I have a question.
>
> Why does automotive engine usage get measured in miles/kms and any other
> heavy duty application get measured in hours?
>
> Wouldn't these engines from Japan have crazy high hours?
>
> I was speaking with a farmer the other day, and he shed some good light on
> the whole oil change thing.... He said John Deere recommends an oil change
> every 300-400 hours.
>
> If I translate that length of time into KMs in my car, assuming my average
> speed is around 50km/h, (I do alot of highway miles) that would mean that 300
> hours is 15000kms? For the record, I change every 5000kms. But why the
> discrepancy?
>
> I buy heavy duty diesel engines for a living. I don't maintain them for a
> living though... otherwise I would know Cummins' intervals for oil changes.
> But I do happen to know on the design side that oil filtration is really no
> different on these heavy duty applications than on the average consumer
> vehicle.
>
> Comments?

very good question! to skip forward a bit, there's quite a bit of
movement in the industry towards pushing out oil change intervals.
there's two main methods - one is using the ecu to log usage and
electronically compare that with a table of oil conditions. the other is
measuring dielectric constant and mapping that in much the same way.
the expensive option is actual spark spectroscopy analysis like they use
in f1, but i'm not aware of that being used in production vehicles.

biggest reason for hour-based changes vs mileage is that with a lot of
diesels, [generators, etc.] there /are/ no miles to log! farm gear
doesn't cover a lot of mileage either.

regarding discrepancy, big commercial diesels tend to have a much more
regular life than the average passenger car. not only do diesels wear
less on cold start [diesel wetting a cylinder wall is a lubricant, not a
dilutant like gasoline], they tend to have a lot fewer cold starts too.
a lot of trucks run for days on end, marine diesels for months on end.
this means the oil has less crud in it from the cold start process
which helps. then there's filtration. a lot of big diesels have two
filters - one is full flow, the other is bypass. the bypass filter
pulls out all the fine stuff the full flow filter doesn't, and this
keeps the oil in pretty good shape. a lot of commercial fleets are also
supported by oil analysis and usage logging. a vehicle used on a
regular route can have its oil change strategy "tuned" very accurately.
hardly any passenger cars do this, so manufacturers are really trying
to cover hugely different usage patters with their recommended service
intervals.

but the bottom line on all this though is what the market supports.
even my old 89 civic has a 7500 mile change interval. yet who here
waits that long? the later civics have 10k as their interval - at
30mph, that's 333 hours, not far off john deere's diesel spec. again,
there's a lot of resistance among american consumers about extended
change intervals with people routinely ignoring the onboard diagnostics
and getting oil changed 2 or even 3 times before the oil service
notification comes on. i don't see us embracing much beyond 10k unless
there's a massive public education campaign, but that's against the
interests of the oil industry, so that ain't going to happen! otoh, i
hear that the europeans are very keen on long change intervals and for
pushing it out as far as possible with up to 30k on some of the euro
cars. of course, improved lubricants play a significant role in that too.

>
> t
>
> jim beam wrote:
>>> thanks jim,
>>>
>> [quoted text clipped - 3 lines]
>>> also, is this industry legit? as in, are the mileages they quote for
>>> real or is it just B.S.? would i be better off going to the junk yard?
>> no, it's legit. mileages should be about right - other markets,
>> particularly japan, do much lower mileage than us. that's why i'd only
>> buy a domestic motor in emergency - /much/ higher mileage. but that
>> said, there's no reason a d15 can't do 300k miles if it's not been
>> cracked and has had the oil changed regularly.
>>
>> i'm not endorsing any of the following:
>> http://www.sunrisejdmmotors.com/
>> http://www.nippon-motors.com/honda.htm
>> http://www.naganojapanese.com/
>>
>> there are a bunch of others if you google.
>>
>> good luck!
>>
>>> thanks again (exciting saturday, right?).
>> you're not going anywhere with that motor!
>>
>>>>> i've done some looking online and it's difficult to discern what's what
>>>>> and if a given website is legitimate. that's the biggest difficulty.
>> [quoted text clipped - 50 lines]
>>>>>> a number of possible causes, all of which are cheaper and less
>>>>>> troublesome than replacing the whole unit.
>

 

"loewent via CarKB.com" <u10197@uwe> wrote in message
news:6ba7ab0474175@uwe...
> Why does automotive engine usage get measured in miles/kms and any other
> heavy duty application get measured in hours?
>
My guess is that diesel engines need service more by hours of operation than
gasoline engines do. Couple that with the sort of duty many of those engines
get - miles traveled not being a good measure of usage and sometimes being
used in stationary applications - and doing those by miles is pretty
far-fetched. Airplanes powered by gasoline engines are the same way.
Maintenance is done by the hour meter and probably still would even if there
were an odometer to read.

Disclaimer - I am not very familiar with diesels. I've been driving a Ford
F350 diesel at work for about a year and have operated a diesel snow cat.
Interestingly, although the snow cat has an odometer, its fuel consumption
is estimated in terms of hours of operation rather than miles.

Mike

 

"loewent via CarKB.com" <u10197@uwe> wrote in message
news:6ba7ab0474175@uwe...
> Why does automotive engine usage get measured in miles/kms and any other
> heavy duty application get measured in hours?
>
My guess is that diesel engines need service more by hours of operation than
gasoline engines do. Couple that with the sort of duty many of those engines
get - miles traveled not being a good measure of usage and sometimes being
used in stationary applications - and doing those by miles is pretty
far-fetched. Airplanes powered by gasoline engines are the same way.
Maintenance is done by the hour meter and probably still would even if there
were an odometer to read.

Disclaimer - I am not very familiar with diesels. I've been driving a Ford
F350 diesel at work for about a year and have operated a diesel snow cat.
Interestingly, although the snow cat has an odometer, its fuel consumption
is estimated in terms of hours of operation rather than miles.

Mike

 

"loewent via CarKB.com" <u10197@uwe> wrote in message
news:6ba7ab0474175@uwe...
> Why does automotive engine usage get measured in miles/kms and any other
> heavy duty application get measured in hours?
>
My guess is that diesel engines need service more by hours of operation than
gasoline engines do. Couple that with the sort of duty many of those engines
get - miles traveled not being a good measure of usage and sometimes being
used in stationary applications - and doing those by miles is pretty
far-fetched. Airplanes powered by gasoline engines are the same way.
Maintenance is done by the hour meter and probably still would even if there
were an odometer to read.

Disclaimer - I am not very familiar with diesels. I've been driving a Ford
F350 diesel at work for about a year and have operated a diesel snow cat.
Interestingly, although the snow cat has an odometer, its fuel consumption
is estimated in terms of hours of operation rather than miles.

Mike

 

larson.joshua@gmail.com wrote:
> car runs okay, but here's the thing it did after 1st and 2nd head
> gasket job: after i drive for a while, some kind of gas gets into the
> cooling system. it bubbles, not boils, pretty vigorously after i come
> home (up a mountainside). i could live with this, but i have to check
> the fluid levels every couple days now. the gas pushes coolant out,
> overflows the resevoir, makes a mess and then i have to fill it back
> up.

Your description sounds like the head gasket is leaking again.

DEspite your not wanting to work on this motor much more you can try to
unscrew and re-torque each head bolt. Sometimes you can get them to seal
again. Another thing is did you use any assembly lube on the head bolts
so you can get an accurate torque AND something I do on every hole is to
run a tap through it. Both of these steps will let you get a much more
accurate toque and keep the gremlins away.


-SP

 

larson.joshua@gmail.com wrote:
> car runs okay, but here's the thing it did after 1st and 2nd head
> gasket job: after i drive for a while, some kind of gas gets into the
> cooling system. it bubbles, not boils, pretty vigorously after i come
> home (up a mountainside). i could live with this, but i have to check
> the fluid levels every couple days now. the gas pushes coolant out,
> overflows the resevoir, makes a mess and then i have to fill it back
> up.

Your description sounds like the head gasket is leaking again.

DEspite your not wanting to work on this motor much more you can try to
unscrew and re-torque each head bolt. Sometimes you can get them to seal
again. Another thing is did you use any assembly lube on the head bolts
so you can get an accurate torque AND something I do on every hole is to
run a tap through it. Both of these steps will let you get a much more
accurate toque and keep the gremlins away.


-SP

 

larson.joshua@gmail.com wrote:
> car runs okay, but here's the thing it did after 1st and 2nd head
> gasket job: after i drive for a while, some kind of gas gets into the
> cooling system. it bubbles, not boils, pretty vigorously after i come
> home (up a mountainside). i could live with this, but i have to check
> the fluid levels every couple days now. the gas pushes coolant out,
> overflows the resevoir, makes a mess and then i have to fill it back
> up.

Your description sounds like the head gasket is leaking again.

DEspite your not wanting to work on this motor much more you can try to
unscrew and re-torque each head bolt. Sometimes you can get them to seal
again. Another thing is did you use any assembly lube on the head bolts
so you can get an accurate torque AND something I do on every hole is to
run a tap through it. Both of these steps will let you get a much more
accurate toque and keep the gremlins away.


-SP

 

Speedy Pete wrote:
> larson.joshua@gmail.com wrote:
>> car runs okay, but here's the thing it did after 1st and 2nd head
>> gasket job: after i drive for a while, some kind of gas gets into the
>> cooling system. it bubbles, not boils, pretty vigorously after i come
>> home (up a mountainside). i could live with this, but i have to check
>> the fluid levels every couple days now. the gas pushes coolant out,
>> overflows the resevoir, makes a mess and then i have to fill it back
>> up.
>
> Your description sounds like the head gasket is leaking again.
>
> DEspite your not wanting to work on this motor much more you can try to
> unscrew and re-torque each head bolt. Sometimes you can get them to seal
> again. Another thing is did you use any assembly lube on the head bolts
> so you can get an accurate torque AND something I do on every hole is to
> run a tap through it. Both of these steps will let you get a much more
> accurate toque and keep the gremlins away.

even if this weren't a waste of time on a motor with a cracked block,
it's a waste of time on a car with a gasket that's leaked. leak once,
leak always. /always/. no amount of re-torquing will cure it.

 

Speedy Pete wrote:
> larson.joshua@gmail.com wrote:
>> car runs okay, but here's the thing it did after 1st and 2nd head
>> gasket job: after i drive for a while, some kind of gas gets into the
>> cooling system. it bubbles, not boils, pretty vigorously after i come
>> home (up a mountainside). i could live with this, but i have to check
>> the fluid levels every couple days now. the gas pushes coolant out,
>> overflows the resevoir, makes a mess and then i have to fill it back
>> up.
>
> Your description sounds like the head gasket is leaking again.
>
> DEspite your not wanting to work on this motor much more you can try to
> unscrew and re-torque each head bolt. Sometimes you can get them to seal
> again. Another thing is did you use any assembly lube on the head bolts
> so you can get an accurate torque AND something I do on every hole is to
> run a tap through it. Both of these steps will let you get a much more
> accurate toque and keep the gremlins away.

even if this weren't a waste of time on a motor with a cracked block,
it's a waste of time on a car with a gasket that's leaked. leak once,
leak always. /always/. no amount of re-torquing will cure it.

 

Speedy Pete wrote:
> larson.joshua@gmail.com wrote:
>> car runs okay, but here's the thing it did after 1st and 2nd head
>> gasket job: after i drive for a while, some kind of gas gets into the
>> cooling system. it bubbles, not boils, pretty vigorously after i come
>> home (up a mountainside). i could live with this, but i have to check
>> the fluid levels every couple days now. the gas pushes coolant out,
>> overflows the resevoir, makes a mess and then i have to fill it back
>> up.
>
> Your description sounds like the head gasket is leaking again.
>
> DEspite your not wanting to work on this motor much more you can try to
> unscrew and re-torque each head bolt. Sometimes you can get them to seal
> again. Another thing is did you use any assembly lube on the head bolts
> so you can get an accurate torque AND something I do on every hole is to
> run a tap through it. Both of these steps will let you get a much more
> accurate toque and keep the gremlins away.

even if this weren't a waste of time on a motor with a cracked block,
it's a waste of time on a car with a gasket that's leaked. leak once,
leak always. /always/. no amount of re-torquing will cure it.