3 speed Dodge Ram Van oil consumption

"Matt Whiting" > wrote in message
...
> Bob wrote:
>
>> "Daniel J. Stern" > wrote in message
>> n.umich.edu...
>>
>>>On Thu, 7 Oct 2004, John Kunkel wrote:
>>>
>>>
>>>>>The engine speed is not connected with the oil consumption. If your
>>>>>engine "consumed" (or lost) 4 quarts of oil in 800 miles, you either
>>>>>have a whipped engine or a large leak.
>>>>
>>>>Disagree, many vans had ridiculously low axle ratios and the absence of
>>>>OD would have the motor running at 3500+ rpm's at freeway speeds. A
>>>>tired motor will suck more oil at 3500 than it will at 1800.
>>>
>>>...and a non-tired engine will use no more oil at 3500 than at 1800.
>>
>>
>> But it will "get" tired at least twice as fast
>
> Not necessarily.
>
>
> Matt
>

If everything else is equal it certainly well.
Bob

On Thu, 7 Oct 2004 20:23:05 -0500, "Bob" > wrote:

>
>"Matt Whiting" > wrote in message
...
>> Bob wrote:
>>
>>> "Daniel J. Stern" > wrote in message
>>> n.umich.edu...
>>>
>>>>On Thu, 7 Oct 2004, John Kunkel wrote:
>>>>
>>>>
>>>>>>The engine speed is not connected with the oil consumption. If your
>>>>>>engine "consumed" (or lost) 4 quarts of oil in 800 miles, you either
>>>>>>have a whipped engine or a large leak.
>>>>>
>>>>>Disagree, many vans had ridiculously low axle ratios and the absence of
>>>>>OD would have the motor running at 3500+ rpm's at freeway speeds. A
>>>>>tired motor will suck more oil at 3500 than it will at 1800.
>>>>
>>>>...and a non-tired engine will use no more oil at 3500 than at 1800.
>>>
>>>
>>> But it will "get" tired at least twice as fast
>>
>> Not necessarily.
>>
>>
>> Matt
>>
>
>If everything else is equal it certainly well.
> Bob
>
But not all else IS equal. Given the same load, the engine running at
higher RPM is running under less load (less torque) which translates
to lower cyl pressures, lower bearing loads, etc. A "free running"
engine generally lasts longer than a lugged engine.

Not saying the high revving engine WILL last longer, but it's not as
simple as "engine runs twice as fast, wears twice as fast (or more)"

On Thu, 7 Oct 2004 20:23:05 -0500, "Bob" > wrote:

>
>"Matt Whiting" > wrote in message
...
>> Bob wrote:
>>
>>> "Daniel J. Stern" > wrote in message
>>> n.umich.edu...
>>>
>>>>On Thu, 7 Oct 2004, John Kunkel wrote:
>>>>
>>>>
>>>>>>The engine speed is not connected with the oil consumption. If your
>>>>>>engine "consumed" (or lost) 4 quarts of oil in 800 miles, you either
>>>>>>have a whipped engine or a large leak.
>>>>>
>>>>>Disagree, many vans had ridiculously low axle ratios and the absence of
>>>>>OD would have the motor running at 3500+ rpm's at freeway speeds. A
>>>>>tired motor will suck more oil at 3500 than it will at 1800.
>>>>
>>>>...and a non-tired engine will use no more oil at 3500 than at 1800.
>>>
>>>
>>> But it will "get" tired at least twice as fast
>>
>> Not necessarily.
>>
>>
>> Matt
>>
>
>If everything else is equal it certainly well.
> Bob
>
But not all else IS equal. Given the same load, the engine running at
higher RPM is running under less load (less torque) which translates
to lower cyl pressures, lower bearing loads, etc. A "free running"
engine generally lasts longer than a lugged engine.

Not saying the high revving engine WILL last longer, but it's not as
simple as "engine runs twice as fast, wears twice as fast (or more)"

> wrote in message
...
> On Thu, 7 Oct 2004 20:23:05 -0500, "Bob" > wrote:
>
>>
>>"Matt Whiting" > wrote in message
...
>>> Bob wrote:
>>>
>>>> "Daniel J. Stern" > wrote in message
>>>> n.umich.edu...
>>>>
>>>>>On Thu, 7 Oct 2004, John Kunkel wrote:
>>>>>
>>>>>
>>>>>>>The engine speed is not connected with the oil consumption. If your
>>>>>>>engine "consumed" (or lost) 4 quarts of oil in 800 miles, you either
>>>>>>>have a whipped engine or a large leak.
>>>>>>
>>>>>>Disagree, many vans had ridiculously low axle ratios and the absence
>>>>>>of
>>>>>>OD would have the motor running at 3500+ rpm's at freeway speeds. A
>>>>>>tired motor will suck more oil at 3500 than it will at 1800.
>>>>>
>>>>>...and a non-tired engine will use no more oil at 3500 than at 1800.
>>>>
>>>>
>>>> But it will "get" tired at least twice as fast
>>>
>>> Not necessarily.
>>>
>>>
>>> Matt
>>>
>>
>>If everything else is equal it certainly well.
>> Bob
>>
> But not all else IS equal. Given the same load, the engine running at
> higher RPM is running under less load (less torque) which translates
> to lower cyl pressures, lower bearing loads, etc. A "free running"
> engine generally lasts longer than a lugged engine.
>
Okay, lets take a stock Chevy V-8 for example. You can run it at 3500 RPMs
loaded at WOT for days on end with no problems. Run that same engine at 7000
with only a light load and its life will be measured in seconds. Why is
that? Given your explaination of the low cylinder pressures and light loads
it should last a long time. In reality loads and stresses rise very fast as
the speed goes up.

> Not saying the high revving engine WILL last longer, but it's not as
> simple as "engine runs twice as fast, wears twice as fast (or more)"

I was being conservative.......
Bob

> wrote in message
...
> On Thu, 7 Oct 2004 20:23:05 -0500, "Bob" > wrote:
>
>>
>>"Matt Whiting" > wrote in message
...
>>> Bob wrote:
>>>
>>>> "Daniel J. Stern" > wrote in message
>>>> n.umich.edu...
>>>>
>>>>>On Thu, 7 Oct 2004, John Kunkel wrote:
>>>>>
>>>>>
>>>>>>>The engine speed is not connected with the oil consumption. If your
>>>>>>>engine "consumed" (or lost) 4 quarts of oil in 800 miles, you either
>>>>>>>have a whipped engine or a large leak.
>>>>>>
>>>>>>Disagree, many vans had ridiculously low axle ratios and the absence
>>>>>>of
>>>>>>OD would have the motor running at 3500+ rpm's at freeway speeds. A
>>>>>>tired motor will suck more oil at 3500 than it will at 1800.
>>>>>
>>>>>...and a non-tired engine will use no more oil at 3500 than at 1800.
>>>>
>>>>
>>>> But it will "get" tired at least twice as fast
>>>
>>> Not necessarily.
>>>
>>>
>>> Matt
>>>
>>
>>If everything else is equal it certainly well.
>> Bob
>>
> But not all else IS equal. Given the same load, the engine running at
> higher RPM is running under less load (less torque) which translates
> to lower cyl pressures, lower bearing loads, etc. A "free running"
> engine generally lasts longer than a lugged engine.
>
Okay, lets take a stock Chevy V-8 for example. You can run it at 3500 RPMs
loaded at WOT for days on end with no problems. Run that same engine at 7000
with only a light load and its life will be measured in seconds. Why is
that? Given your explaination of the low cylinder pressures and light loads
it should last a long time. In reality loads and stresses rise very fast as
the speed goes up.

> Not saying the high revving engine WILL last longer, but it's not as
> simple as "engine runs twice as fast, wears twice as fast (or more)"

I was being conservative.......
Bob

"Nomen Nescio" > wrote in message
...
> From Nomen Nescio:
>
> Do me a favor and check out your crankcase breather system. A clogged up
> PCV might be your problem. Temporarily disconnect the tubing from the
> rocker cover and drive a few days as a test. If your oil consumption
> returns to normal, pinpoint the problem and fix it.
>
> Another cause of heavy oil consumption is intake valve guide oil seals.
> Look at your plugs. Are they oily? If so, pull the rocker covers and
> squirt auto trans oil on the rockers while the engine is idling. If you
> see smoke coming out the tail pipe, your seals are bad.
>
Loose intake guides and/or bad seals will show up during long deceleration
periods -- check for a blue cloud following you down a long hill. Bad rings
will show up during acceleration -- check for a blue cloud following you up
a long grade.

Bryan

"Nomen Nescio" > wrote in message
...
> From Nomen Nescio:
>
> Do me a favor and check out your crankcase breather system. A clogged up
> PCV might be your problem. Temporarily disconnect the tubing from the
> rocker cover and drive a few days as a test. If your oil consumption
> returns to normal, pinpoint the problem and fix it.
>
> Another cause of heavy oil consumption is intake valve guide oil seals.
> Look at your plugs. Are they oily? If so, pull the rocker covers and
> squirt auto trans oil on the rockers while the engine is idling. If you
> see smoke coming out the tail pipe, your seals are bad.
>
Loose intake guides and/or bad seals will show up during long deceleration
periods -- check for a blue cloud following you down a long hill. Bad rings
will show up during acceleration -- check for a blue cloud following you up
a long grade.

Bryan

Bob wrote:
> > wrote in message
> ...
>
>>On Thu, 7 Oct 2004 20:23:05 -0500, "Bob" > wrote:
>>
>>
>>>"Matt Whiting" > wrote in message
...
>>>
>>>>Bob wrote:
>>>>
>>>>
>>>>>"Daniel J. Stern" > wrote in message
>>>>>news:Pine.GSO.4.58.0410071438280.16624@alumni .engin.umich.edu...
>>>>>
>>>>>
>>>>>>On Thu, 7 Oct 2004, John Kunkel wrote:
>>>>>>
>>>>>>
>>>>>>
>>>>>>>>The engine speed is not connected with the oil consumption. If your
>>>>>>>>engine "consumed" (or lost) 4 quarts of oil in 800 miles, you either
>>>>>>>>have a whipped engine or a large leak.
>>>>>>>
>>>>>>>Disagree, many vans had ridiculously low axle ratios and the absence
>>>>>>>of
>>>>>>>OD would have the motor running at 3500+ rpm's at freeway speeds. A
>>>>>>>tired motor will suck more oil at 3500 than it will at 1800.
>>>>>>
>>>>>>...and a non-tired engine will use no more oil at 3500 than at 1800.
>>>>>
>>>>>
>>>>>But it will "get" tired at least twice as fast
>>>>
>>>>Not necessarily.
>>>>
>>>>
>>>>Matt
>>>>
>>>
>>>If everything else is equal it certainly well.
>>> Bob
>>>
>>
>>But not all else IS equal. Given the same load, the engine running at
>>higher RPM is running under less load (less torque) which translates
>>to lower cyl pressures, lower bearing loads, etc. A "free running"
>>engine generally lasts longer than a lugged engine.
>>
>
> Okay, lets take a stock Chevy V-8 for example. You can run it at 3500 RPMs
> loaded at WOT for days on end with no problems. Run that same engine at 7000
> with only a light load and its life will be measured in seconds. Why is
> that? Given your explaination of the low cylinder pressures and light loads
> it should last a long time. In reality loads and stresses rise very fast as
> the speed goes up.
>
>
>>Not saying the high revving engine WILL last longer, but it's not as
>>simple as "engine runs twice as fast, wears twice as fast (or more)"
>
>
> I was being conservative.......
> Bob

You've got competing stress and wear mechanisms going on, and it all has
to do with metal-to-metal contact and wear:
(1) At low speeds, as was mentioned, under high cylinder pressure, the
oil film in the rod bearings gets squeezed out, and you get
metal-to-metal contact of the wear surfaces.
(2) At super high speeds, loaded or not, with stresses going up by
square laws and such, the mass inertia of the piston/rod assy. changing
direction and the huge forces thus generated is what squeezes out the
oil film, and you get metal-to-metal contact of the wear surfaces
(combined with rubbing at high speed).

IOW - too slow increases wear; too fast increases wear. There's a huge
range in between where the oil is there doing its job. In that range,
bearing life is almost indefinite (then there's dry startup wear).

Bill Putney
(To reply by e-mail, replace the last letter of the alphabet in my
adddress with the letter 'x')

Bob wrote:
> > wrote in message
> ...
>
>>On Thu, 7 Oct 2004 20:23:05 -0500, "Bob" > wrote:
>>
>>
>>>"Matt Whiting" > wrote in message
...
>>>
>>>>Bob wrote:
>>>>
>>>>
>>>>>"Daniel J. Stern" > wrote in message
>>>>>news:Pine.GSO.4.58.0410071438280.16624@alumni .engin.umich.edu...
>>>>>
>>>>>
>>>>>>On Thu, 7 Oct 2004, John Kunkel wrote:
>>>>>>
>>>>>>
>>>>>>
>>>>>>>>The engine speed is not connected with the oil consumption. If your
>>>>>>>>engine "consumed" (or lost) 4 quarts of oil in 800 miles, you either
>>>>>>>>have a whipped engine or a large leak.
>>>>>>>
>>>>>>>Disagree, many vans had ridiculously low axle ratios and the absence
>>>>>>>of
>>>>>>>OD would have the motor running at 3500+ rpm's at freeway speeds. A
>>>>>>>tired motor will suck more oil at 3500 than it will at 1800.
>>>>>>
>>>>>>...and a non-tired engine will use no more oil at 3500 than at 1800.
>>>>>
>>>>>
>>>>>But it will "get" tired at least twice as fast
>>>>
>>>>Not necessarily.
>>>>
>>>>
>>>>Matt
>>>>
>>>
>>>If everything else is equal it certainly well.
>>> Bob
>>>
>>
>>But not all else IS equal. Given the same load, the engine running at
>>higher RPM is running under less load (less torque) which translates
>>to lower cyl pressures, lower bearing loads, etc. A "free running"
>>engine generally lasts longer than a lugged engine.
>>
>
> Okay, lets take a stock Chevy V-8 for example. You can run it at 3500 RPMs
> loaded at WOT for days on end with no problems. Run that same engine at 7000
> with only a light load and its life will be measured in seconds. Why is
> that? Given your explaination of the low cylinder pressures and light loads
> it should last a long time. In reality loads and stresses rise very fast as
> the speed goes up.
>
>
>>Not saying the high revving engine WILL last longer, but it's not as
>>simple as "engine runs twice as fast, wears twice as fast (or more)"
>
>
> I was being conservative.......
> Bob

You've got competing stress and wear mechanisms going on, and it all has
to do with metal-to-metal contact and wear:
(1) At low speeds, as was mentioned, under high cylinder pressure, the
oil film in the rod bearings gets squeezed out, and you get
metal-to-metal contact of the wear surfaces.
(2) At super high speeds, loaded or not, with stresses going up by
square laws and such, the mass inertia of the piston/rod assy. changing
direction and the huge forces thus generated is what squeezes out the
oil film, and you get metal-to-metal contact of the wear surfaces
(combined with rubbing at high speed).

IOW - too slow increases wear; too fast increases wear. There's a huge
range in between where the oil is there doing its job. In that range,
bearing life is almost indefinite (then there's dry startup wear).

Bill Putney
(To reply by e-mail, replace the last letter of the alphabet in my
adddress with the letter 'x')

Bob wrote:

> "Matt Whiting" > wrote in message
> ...
>
>>Bob wrote:
>>
>>
>>>"Daniel J. Stern" > wrote in message
ngin.umich.edu...
>>>
>>>
>>>>On Thu, 7 Oct 2004, John Kunkel wrote:
>>>>
>>>>
>>>>
>>>>>>The engine speed is not connected with the oil consumption. If your
>>>>>>engine "consumed" (or lost) 4 quarts of oil in 800 miles, you either
>>>>>>have a whipped engine or a large leak.
>>>>>
>>>>>Disagree, many vans had ridiculously low axle ratios and the absence of
>>>>>OD would have the motor running at 3500+ rpm's at freeway speeds. A
>>>>>tired motor will suck more oil at 3500 than it will at 1800.
>>>>
>>>>...and a non-tired engine will use no more oil at 3500 than at 1800.
>>>
>>>
>>>But it will "get" tired at least twice as fast
>>
>>Not necessarily.
>>
>>
>>Matt
>>
>
>
> If everything else is equal it certainly well.

Everything else isn't even close to equal. It is pretty well documented
that most wear occurs during startup, especially when the engine is
cold. Running at twice the RPM doesn't yield even close to twice the
rate of wear. The difference, in fact, may be virtually negligible.
Cars that are run long periods at a time and not started all that often,
especially cold starts, tend to have engines that last a LOT longer.


Matt