From: John De Armond
Newsgroups: rec.outdoors.rv-travel
Subject: Re: Generator oil Onan Microquiet
Date: Tue, 03 Apr 2007 03:05:04 -0400
Message-ID: <hsu313l34ai9qdhg1hu5e41tib6b3spshp@4ax.com>

On Mon, 02 Apr 2007 17:51:43 -0700, altar nospam <altar@nospam.net>
wrote:


>LOL. You will never convince me that you will destroy your engine
>first time out by putting 30W oil in it. Over time it will not be good
>for it, for sure. But suicide? You are ridiculous.

Everybody who's run say, Valvoline straight 30wt (or worse, 50wt)
racing oil in a competition engine and made the mistake of cranking it
on a cold morning without first warming the oil and therefore spun one
or more crank or rod bearings, raise their hands.

I'll be the first. <hands wildly waving in the air>

John

From: John De Armond
Newsgroups: rec.outdoors.rv-travel
Subject: Re: Generator oil Onan Microquiet
Date: Tue, 03 Apr 2007 16:18:34 -0400
Message-ID: <5cd5139785t1nqtpa6jvo5p44brcgh2n38@4ax.com>

On Tue, 03 Apr 2007 12:31:11 -0700, altar@nospam.net wrote:

>On Tue, 03 Apr 2007 03:05:04 -0400, Neon John <no@never.com> wrote:
>
>>On Mon, 02 Apr 2007 17:51:43 -0700, altar nospam <altar@nospam.net>
>>wrote:
>>
>>
>>>LOL. You will never convince me that you will destroy your engine
>>>first time out by putting 30W oil in it. Over time it will not be good
>>>for it, for sure. But suicide? You are ridiculous.
>>
>>Everybody who's run say, Valvoline straight 30wt (or worse, 50wt)
>>racing oil in a competition engine and made the mistake of cranking it
>>on a cold morning without first warming the oil and therefore spun one
>>or more crank or rod bearings, raise their hands.
>>
>>I'll be the first. <hands wildly waving in the air>
>
>We weren't talking about competition engines. But if I ever do have
>access to a competition engine, I'll remember your advice. <g>

I mentioned competition engines because that's the most likely place
to actually find single weight oil.  Put that same straight weight oil
in your street engine and try to crank it under the same conditions
and you too will risk spinning bearings.  In fact, I recall an ad
campaign by Valvoline to DIScourage the use of "racing oil" in street
engines for just this reason.  Lots of, um, shadetree mechanics equate
anything "racing" with "fast".

But hey, what do I care?  Slap some 30wt in your 'tater hauler and
give it a shot.  Some folks have to learn the hard way.

John

From: John De Armond
Newsgroups: rec.outdoors.rv-travel
Subject: Re: Generator oil Onan Microquiet
Date: Tue, 03 Apr 2007 18:36:28 -0400
Message-ID: <c5j513t0kt8d5g6qek045p8hsc2knulvfv@4ax.com>

On Tue, 03 Apr 2007 14:22:53 -0700, altar@nospam.net wrote:

>On Tue, 03 Apr 2007 16:18:34 -0400, Neon John <no@never.com> wrote:
>
>>>We weren't talking about competition engines. But if I ever do have
>>>access to a competition engine, I'll remember your advice. <g>
>>
>>I mentioned competition engines because that's the most likely place
>>to actually find single weight oil.  Put that same straight weight oil
>>in your street engine and try to crank it under the same conditions
>>and you too will risk spinning bearings.  In fact, I recall an ad
>>campaign by Valvoline to DIScourage the use of "racing oil" in street
>>engines for just this reason.  Lots of, um, shadetree mechanics equate
>>anything "racing" with "fast".
>>
>>But hey, what do I care?  Slap some 30wt in your 'tater hauler and
>>give it a shot.  Some folks have to learn the hard way.
>>
>>John
>
>I did some research on this. Better, I even talked to two local
>experts on the subject. Not shadetree mechanics like a lot on this NG,
>but people who know engines, and the molecular structure of oil.
>
>They tell me that your view on this is a popular misconception. I am
>informed that the reason for multi grade oil is solely to meet the
>CAFE standards for mileage. I am told that while some tolerances in
>the bottom end are  1 to 3 thousandths on a normal car, even straight
>weight oils molecular structures easily fit into that space, even in
>cold temperatures, especially when pushed typically at 60 pounds. If
>they fit in that space, they then separate the metals by a thin film.
>And they do that regardless of whether it is 30 weight, or a multi
>viscosity.
>
>Anything else is hype or misinformation.

Yep, and you got it wrong.  The move to LOWER viscosity oil - 5W25 and
5W30 - is part of CAFE compliance.  It should be obvious even to you,
Tom, that multi-vis oil itself has nothing to do with CAFE since
they've been around since what?  The 50s.

The purpose of multi-vis oil is simply to provide a constant viscosity
over the widest possible temperature range.  Make single weight oil
thin enough to pump at zero degrees and it won't do the job at all at
100.  Oil thick enough to do the job at 100 deg is like molasses at
zero.  Say Tom, why don't you buy some 30wt and stick it in your
freezer and see what it's like at 0 or -10 or whatever your freezer
runs at?

BTW, it isn't the oil pressure nor the viscosity that does the work in
a plain bearing.  Even water will work, as evidenced by the water
lubed bearings used in most very large water pumps.  Oil pressure is
there simply to overcome the hydrodynamic pressure generated as the
bearing operates.  Oil's viscosity is important as far as the plain
bearings go only for start up before oil pressure builds.

As for your 1 to 3 thousands clearance on bottom end bearings, that's
very old information.  Modern CNC machining and automated measuring
techniques has enabled that clearance to be dramatically reduced. Even
over 10 years ago that was the case.  The service limit on my 94
Caprice's LT1 engine is 1.5 thou.  The assembly clearance is a
fraction of that.

When the engine was assembled, automated machinery measured each
journal and saddle and select-fitted the proper bearing.  Physically,
the assembly technician has a computer screen that tells him from
which bin to pull the bearing for each journal.  That information is
several years old, as I've not been in an engine plant in awhile. They
probably have the entire process automated by now.

The reason for this was two-fold.  Longer engine life (gas engines now
last almost as long as diesels of the past) and CAFE.  CAFE in that
tighter clearances permit less oil to be pumped and that requires less
HP.

BTW, I got bit by the viscosity bug just a few years ago when I was
working on my latest CBC.
http://bellsouthpwp.net/j/o/johngd/files/rv/cordless_battery_charger/

The Honda GC engine uses a cog-belt-driven overhead cam.  A major
reason I selected that engine, as it is considerably quieter than the
chain driven version.

The first time I tried to use the CBC on a camping trip with the
temperature in the low single digits, when I cranked it, it hit a few
strokes and died.  No compression.  I popped the valve cover and could
see that the timing belt was broken.

When I took it back to Northern for warranty, the mechanic asked me if
I had been using it in cold weather.  Somewhat surprised, I said yes.
He said that Honda had issued a bulletin that for this first
production run of engines, only 5Wxx and preferably Mobil 1 5W25 oil
be used.

Seems that at low temperatures, the thick oil adhered to the timing
belt and was carried to the upper sprocket where it built up under the
belt thick enough to break it.  Later runs, including my replacement
engine, have added baffles to help strip oil off the timing belt.  I
still run Mobil 1 in all my air cooled engines.

BTW, Tom, if you want to actually know something about engine
lubrication instead of that bad info you got from your "experts",
might I suggest:

http://www.sae.org/technical/books/SP-1967
http://www.sae.org/technical/books/SP-1894
http://www.sae.org/technical/books/SP-1624

The last one isn't too expensive and addresses specifically passenger
car engine lubrication.  Yeah, ya gotta spend a little jack to get
these....

John