Edward W. Thompson

On Mon, 27 Apr 2009 05:54:25 -0700, jim beam
<retard-finger@bad.example.net> wrote:

>Edward W. Thompson wrote:
>> On Sun, 26 Apr 2009 07:26:15 -0700, jim beam
>> <retard-finger@bad.example.net> wrote:
>>
>>> Big Al wrote:
>>>> Is it possible to feel a difference (smoothness, better acceleration,
>>>> etc.) after a normal-interlude oil change? Someone is claiming this and
>>>> I think it's just their imagination, but I was wondering if there'd be
>>>> any technical reason. I can't think of one, unless the oil was quarts
>>>> low or something drastic, which it wasn't.
>>>>
>>>> Thanks--
>>>> Al
>>> of course you could, although it really depends on the state of the old
>>> oil.
>>>
>>> usually, oil goes up in viscosity as particle load increases with age,
>>> so the engine will be having to work very slightly harder against that.
>>> you'd not expect a big difference on changing to fresh, but it can be
>>> there. i doubt that recreational oil changers that compulsively do it
>>> every 2k miles will notice anything.
>>
>> What a complete lot of nonsense. If the lubricity of the oil changes
>> in any perceptable degree, the engine bearings will fail.
>
>you've worked with cars for /how/ long???
>
>
>> Particle
>> entrainment in the oil does not increase viscosity.
>
>how odd - when you /measure/ viscosity over time, if the base doesn't
>degrade, viscosity goes up! strange how misleading measurements can be!
>
>
>> Incidentally
>> where are these particles coming from?
>
>er, it's called "combustion product". ever heard of that in a
>"combustion engine"?
>
>
>> Surely you are not suggesting
>> these are metallic particles from engine wear.
>
>there's all kinds of crap in there. anything too small for the filter
>remains in the oil. duh.
>
>
>> Where do you people
>> get their technical education from?
>
>clearly a much better place than you.

So long as you have satisfied yourself you are correct that is the end
of the matter no matter how wrong you happen to be.

As an aside, take a glass of water and add a teaspoon full of sand to
it. Shaker it. Does viscosity change? No? I wonder why given you
believe entrained matter changes viscosity. Incidentally viscosity
and lubricity are two separate characteristics.

Combustion products in engine oil are entrained matter although some
oxidation does occur which does not adversely affect lubricity or
viscosity. What does get depleted in engine oil are additives which
are the principal reason for oil change.

On the matter of combustion products, provided the diameter of the
products do not exceed oil film thickness they will do no harm and
will be removed by the filter. Combustion products in the oil of a
well maintained gas engine are minimal as compared to a trunk piston
diesel engine.

jim beam

Edward W. Thompson wrote:
> On Mon, 27 Apr 2009 05:54:25 -0700, jim beam
> <retard-finger@bad.example.net> wrote:
>
>> Edward W. Thompson wrote:
>>> On Sun, 26 Apr 2009 07:26:15 -0700, jim beam
>>> <retard-finger@bad.example.net> wrote:
>>>
>>>> Big Al wrote:
>>>>> Is it possible to feel a difference (smoothness, better acceleration,
>>>>> etc.) after a normal-interlude oil change? Someone is claiming this and
>>>>> I think it's just their imagination, but I was wondering if there'd be
>>>>> any technical reason. I can't think of one, unless the oil was quarts
>>>>> low or something drastic, which it wasn't.
>>>>>
>>>>> Thanks--
>>>>> Al
>>>> of course you could, although it really depends on the state of the old
>>>> oil.
>>>>
>>>> usually, oil goes up in viscosity as particle load increases with age,
>>>> so the engine will be having to work very slightly harder against that.
>>>> you'd not expect a big difference on changing to fresh, but it can be
>>>> there. i doubt that recreational oil changers that compulsively do it
>>>> every 2k miles will notice anything.
>>> What a complete lot of nonsense. If the lubricity of the oil changes
>>> in any perceptable degree, the engine bearings will fail.
>> you've worked with cars for /how/ long???
>>
>>
>>> Particle
>>> entrainment in the oil does not increase viscosity.
>> how odd - when you /measure/ viscosity over time, if the base doesn't
>> degrade, viscosity goes up! strange how misleading measurements can be!
>>
>>
>>> Incidentally
>>> where are these particles coming from?
>> er, it's called "combustion product". ever heard of that in a
>> "combustion engine"?
>>
>>
>>> Surely you are not suggesting
>>> these are metallic particles from engine wear.
>> there's all kinds of crap in there. anything too small for the filter
>> remains in the oil. duh.
>>
>>
>>> Where do you people
>>> get their technical education from?
>> clearly a much better place than you.
>
> So long as you have satisfied yourself you are correct that is the end
> of the matter no matter how wrong you happen to be.
>
> As an aside, take a glass of water and add a teaspoon full of sand to
> it. Shaker it. Does viscosity change? No?

<snip bull>

wow, i love this guy! facts simply don't get in your way, do they!
what's next, mud is the same viscosity as water? 'cos that's the way
/your/ example works buddy.

you need to go back to your old high school and have a word with your
old science teachers - they failed you big time.

Clive

In message <vfadnSGpkPlbBGvUnZ2dnUVZ8rednZ2d@bt.com>, Edward W. Thompson
<thomeduk1@btopenworld.com> writes
>Combustion products in the oil of a
>well maintained gas engine are minimal as compared to a trunk piston
>diesel engine.
What is a trunk piston diesel engine?
--
Clive

Jeff

On Apr 28, 9:12 am, Clive <Cl...@yewbank.demon.co.uk> wrote:
> In message <vfadnSGpkPlbBGvUnZ2dnUVZ8redn...@bt.com>, Edward W. Thompson
> <thomed...@btopenworld.com> writes>Combustion products in the oil of a
> >well maintained gas engine are minimal as compared to a trunk piston
> >diesel engine.
>
> What is a trunk piston diesel engine?
> --
> Clive

Is that a diesel engine in a rear-engine or mid-engine car?

Perhaps he meant "truck diesel engine."

Clive

In message
<aa14ffda-52b3-41fe-bcbd-13bbc774a7f5@z16g2000prd.googlegroups.com>,
Jeff <jeff.utz@gmail.com> writes
>> What is a trunk piston diesel engine?
>> --
>> Clive
>
>Is that a diesel engine in a rear-engine or mid-engine car?
>
>Perhaps he meant "truck diesel engine."
I've googled for it, it just means normal pistons as in any i.c. engine
instead of a thin piston driving a piston rod to a crosshead as in steam
engines.
--
Clive