Re: Illicit Pleasures.

[Egil Kvaleberg <egilk@sn.no>]

On Mon, 10 Feb 1997, Randy Wilson wrote:

> While the actual oil pressure is not what is supporting the bearing, I will
> not agree that an engine can live for several minutes without any
> pressure. The oil in the bearings needs to be constantly replenished.

Why?

Because the bearing friction losses generate so much heat under high
load/RPM conditions that it the oil already present in the bearing quickly
becomes too hot to do any useful lubrication, besides causing heat induced
damage to the bearing surfaces themselves. The oil constantly has to be
replaced with oil of correct temperature. Under heavy load/high RPM
conditions, zero oil pressure will usually cause permanent damage in a
matter of seconds. 

I also have a suspicion that the oil pressure does an important job in 
"cushioning the blow" when, in a four stroke engine, the direction of 
the bearing load changes between the inlet and compression strokes. As 
can be clearly heard in an engine with well worn conrod bearings as a 
clear muting of engine noise when the oil pressure builds up after a cold 
start.  

Egil
-- 
Email: egilk@sn.no  Voice: +47 22523641, 92022780 Fax: +47 22525899
Snail: Egil Kvaleberg, Husebybakken 14A, 0379 Oslo, Norway
URL:   http://home.sn.no/home/egilk/

---

References:

• Re: Illicit Pleasures.
• From: Randy Wilson <randy@taylor.infi.net>

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