"Sucking oil past the rings"

"C. E. White" > wrote in message
...
>While it is true that closing the throttle while the
> engine is turning at high rpm will increase the vaccum in the intake tract
> and cylinders, which may result in pulling more oil past the rings and
> intake valve seals, I don't believe this is beneficial. I'd put this down
as
> an urban legend or old wives tale.
>
> Ed

I agree totally.

"C. E. White" > wrote in message
...
>
> "Hugo Schmeisser" > wrote in message
> ...
>> Many years ago, my father told me it was a good idea to release the
>> accelerator once in a while whilst driving in order to "suck oil past
>> the rings". Apparently this action aided in lubricating the rings in
>> order to prolong their lifespan.
>>
>> Two questions:
>> 1) Is there any truth to this notion?
>> 2) If so, is it applicable to modern cars?
>
> My belief is that the answer is no to both 1 and 2. There is no throttle
> plate to close for diesels and they seem to get by just fine (even
> turbocharged diesels). While it is true that closing the throttle while
> the
> engine is turning at high rpm will increase the vaccum in the intake tract
> and cylinders, which may result in pulling more oil past the rings and
> intake valve seals, I don't believe this is beneficial. I'd put this down
> as
> an urban legend or old wives tale.
>
> Ed
>
>

Sounds like an old husbands tale to me.

Pistons and rings need very, very little oil. When an engine
runs out of oil it's the bearings that go first; they're much more
highly highly loaded than the rings and need constant oil supply. A
microscopic amount of oil on a cylinder wall is more than enough, and
any excess will only get burned and coke up the engine. Too much oil,
as many know, will cause the rings to "hydroplane" and lose their
effectiveness. Worn bearings often contribute to that condition by
allowing too much oil through large bearing clearances.

Dan

wrote:

> Pistons and rings need very, very little oil. When an
> engine runs out of oil it's the bearings that go first; they're much
> more highly highly loaded than the rings and need constant oil
> supply. A microscopic amount of oil on a cylinder wall is more than
> enough, and any excess will only get burned and coke up the engine.
> Too much oil, as many know, will cause the rings to "hydroplane" and
> lose their effectiveness.


By "lose their effectiveness", I assume you mean a temporary loss of
sealing?


Worn bearings often contribute to that
> condition by allowing too much oil through large bearing clearances.
>


Why would this be so? I'm afraid I don't understand the connection.

On Mon, 29 Aug 2005, Hugo Schmeisser wrote:

> > Pistons and rings need very, very little oil. When an
> > engine runs out of oil it's the bearings that go first; they're much
> > more highly highly loaded than the rings and need constant oil supply.
> > A microscopic amount of oil on a cylinder wall is more than enough,
> > and any excess will only get burned and coke up the engine. Too much
> > oil, as many know, will cause the rings to "hydroplane" and lose their
> > effectiveness.

> By "lose their effectiveness", I assume you mean a temporary loss of
> sealing?

That's what's meant.

> > Worn bearings often contribute to that condition by allowing too much
> > oil through large bearing clearances.

> Why would this be so? I'm afraid I don't understand the connection.

Overlarge bearing clearances = more oil squirting and splashing onto the
cylinder walls.