From: paulw@hpspdla.spd.HP.COM (Paul Welch)
Newsgroups: rec.autos.tech
Subject: Pre-luber summary & Oil Changes
Date: 28 Aug 92 16:19:23 GMT
Organization: HP Palo Alto Fabrication Center

Thanks for all of the responses to my question about pre-oilers.  Let
me summarize and provide a little more info (I am impressed at the 
number of responses I got; this must be a common topic?).

Many folks questioned the basic logic of installing a pre-oiler.  Some
felt that just regular oil changes and good car care should be plenty
to get 60-100k out of a motor.  And, some said that the wear I was 
trying to prevent was rarely the ultimate cause of engine failure.
Point well taken.

Some offered info about purchasing one of these pumps.  Thanks, but 
for $560 I'll have to come up with another idea.  A private response
suggested an aux. pressure vessel that is filled with pressurized
oil while the motor runs.  It holds this pressure until the motor is 
re-started; thus no pump and pump motor are required.  Actually
sounds like a viable idea to me.

Here's just a little more background on why I brought this up in the 
first place:  I have two vehicles in particular that this might be
a good idea for.  First, there is my Saab 9000 Turbo.  Saab recommends
that you let the engine idle for 20 to 30 seconds after parking the
car before you shut the engine off, to allow the turbo to cool.
I'd be interested to know if this is a theory or if they have 
ACTUAL DATA that shows some benefit here (I'm skeptical as to 
how well one could cool a turbo with engine oil that is already plenty
hot).  But, if you could circulate that oil for more like 5 minutes,
especially if your not continuing to add heat with the engine running,
now it starts to make sense.  The benefit of having this system in
place for when you go to start the car is really secondary, in this
case.

The second vehicle is a 1968 Ford truck, which runs on propane or
gas.  I have never had this one apart, but I have heard that propane
motors stay really clean inside, due to the nature of the combustion.
With clean oil and super clean fuel, the only thing left to be concerned
about is wear or radical failure.  I can't predict or prevent radical
failure, but I'd be willing to bet most any mode of failure can be 
traced back to some sort of friction.  The friction (wear) is highest
at start-up (we nearly all agreed on that), so if I can reduce it,
I think I can extend the life of the motor.  And why not expect several
hundred thousand miles from an engine?  I wouldn't have a problem with
a motor that lasted indefinitely.  By the way, I do expect a LOT more
from my vehicles than most people, and I'm willing to admit that.

Enough said about the logic behind my questions.  Now, how come I can
go buy an oil pump for a typical Chevy engine for about $25, but if
I want something similar to operate before I start the car, the price 
is $560.  Obviously the latter choice also includes a small motor,
switches, etc., but what are my choices for oil pumps if I want to 
try to build my own pre-oiler?  I need something that won't leak, 
and I would guess that when they build the $25 version that sits in
the oil bath, they don't take the time to seal it perfectly.
Any pump and motor suggestions ?????

Finally, I'd like to plant another seed for some more discussion.
Being an engineer, I've been taught that you make guesses based on
theory, and make decisions based on DATA.  Where is the data for 
the suggested frequency of oil changes???  I'd especially like to hear
from our friend at the GM research center on this one.  Or from someone
at a petroleum company.  A very close friend's father used to work at
a petroleum product analysis firm, where, among other things, they 
analyzed oil from various motors and equipment.  He was also a pilot,
and a certified airframe and engine mechanic.  He preached the 
following:  Oil doesn't really ever need to be changed.  I know that
this is a RADICAL concept for most of us.  He said that with todays
quality lubricants, the only real loss that all the analyses showed
was that the ADDITIVES tended to dissipate or fail in the oil.  
Just adding new oil when the motor needed it, and CHANGING the filter
regularly, was all that was really required.  I'm sure the folks at
Pennzoil wouldn't agree!!!  Of course the $64 question is: would I
try this?  Don't know yet, not enough data !!

What do ya think?

PW