Date: Sun, 24 Oct 1999 23:31:41 -0700
Reply-To: "T.P. Stephens" <doktortim@ROCKISLAND.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: "T.P. Stephens" <doktortim@ROCKISLAND.COM>
Subject: DM: Oil, The 100 hour test.
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I don't know if Porsche was using the 100 hour test before multi-vis oils
were produced or created it in order to test the new lubricants. I suspect
the former.
Regardless, the 100 hour test is specifically designed to test the
effectiveness of motor oil. I suspect it was just the necessary data needed
to insure the best oil was identified at any moment in time for some of the
most expensive, highest quality bearing inserts and crankshafts in the world.
Procedure:
Weigh bearing shells, each, bone dry sparkling clean, to a fraction of
microgram each.
Note results.
Assemble motor per specification.
Set the motor up on test dyno.
Add oil to be tested.
Note manufacturer and weight specification.
Start the motor, set timing/mixture/idle
Run the motor at 3000 rpm for 50 minutes
Increase to redline for 10 minutes
Repeat the last two steps repeatedly until
100 hours have elapsed or the motor fails.
If motor fails before 100 hours, note the time of failure.
In either case, disassemble the motor.
Clean and reweight the bearing shells.
Note weight loss.
Inspect all parts for evidence of wear. (And they use Zeiss optics)
Note details.
(It ain't data if you don't write it down for future reference, study and
comparison.)
Shortly after the release of multi weight oils Porsche recognized a failure
rate with new motors that was of concern to them. (Like two component
failures per hundred vehcles instead of one, a two fold increase, a real
eyebrow raiser to any German Neanderthal Engineer.) The 100 hour test told
them that the early SA multis just weren't cutting it, and advised against
it's use in their cars. The problem was founded on the owner who wanted the
best for his car not realizing that what was then specified was not the new
wizbang multi-vis automotive miricle. That's not a failure of the system.
That's a failure to follow specifications.
By the time multi-weight oil certification reached SD it was a much better
oil. But Porsche wouldn't budge, until they found that if they broke the
motor in with straight weight oil before they ran the test, then changed to
multi eight, they got much better results, just not quite yet good enough
to be specified for initial fill.
I'm guessing, I just don't remember, but it wasn't until the SF grade
ehancement that they finally approved multi-vis for initial fill unto the
life of the engine. That was early 90's. Through the 80's it was factory
fill straight weight for break-in and multi approved thereafter.
What is the oil spec now, SH?? Todays oil is several orders of magnitude a
better lubricant than it was in the 80's.
I was aquainted with a petroleum engineer in the early 70's who explained
to me the nature of the then new multi weight oils. The recollections of
those discussions are as follows:
10W oil has less carbon content than 20W
20W " " " " " " 30W
You get the picture. To make a multi weight oil say, 10-40, you use a
straight low carbon 10w and add polymers and other alchemicals to provide
the characteristics of the high weight rating. The lesson is, the lower
weight the base oil, the less carbon, and the less carbon deposit buildup
on pistons and combustion chambers.
Check your owner's manual. Find the oil specification page. Find the
optimum multi weight for your expected ambiant temperatures. Pick a brand
name oil with the specified weight range. Use a name brand that is
available at any FLAPS and you'll never have a problem finding it.
Valvoline is what I use for these reasons. You can get it anywhere. Look at
the back of the container and read "Ashland Oil Co., Lexington, Ky." Look
at the back of the FLAPS private lable oil (Car Quest, Napa and many
others). It will in many cases say Ashland or "MAC'S Oil Company,
Lexington, Ky. It's all Valvoline. I have heard it suggested that half the
Valvoline production is used for private lable marketing. So you can buy
Valvoline in private lable at the occasional loss leader price of 0.99
cents a quart. Any where in America.
Kendal is danged fine oil but can be very difficult to find. I special
order it by the case if the client specifies it, but it ain't the cheap way
to go.
The reason I switched to Valvoline is another story for another time.
The data generated by several decades by the 100 hour test is proprietory
to Porsche. They sure as hell won't be giving it away nor likely sell it to
a competator. They may give tidbits of info at presentations for auto
industry conventions and such. But only Porsche knows which oils fail their
tests and which particular one show the least wear under servere labratory
controlled
variable testing.
Mercedes publishes a listing of brand name oils in the weights that are
approved for their cars and updates it every few years. VW does it's
testing as well.
How do you know what is better than the specified oil??? You have to do
your own experiment to prove which might be better or you have to accept
the risk of your best guess and see what happens. But the testamonials that
result are not data. I suspect that sales of Duralube and Tuffoil have
never been very promising in Germany.
If you were Bill Gates you could build your own facility and 30 some copies
of the engine for testing and 30 different brands and weights of oil and
some paper and pencils for notes and establish the facts as to which is
best, or maybe he could BUY PORSCHE to get access to the best current data.
So, either take the advice of your favoite psychic hotline or use brand
name oil in the weight specified by the tribe of Neaderthal Engineers who
designed the system in your vehicle. They have so much more data than we do
it's scary.
Doktor Tim
Maintenance Repair and Restoration of European Vehicles
San Juan Island, WA