Hall, Phillip wrote:
> Ok - I will bit on this one. PTFE (Teflon) in oil is a no-no. It plugs
> filters (why the FAA has ban it) and under high pressure and heat (cam
> lobes) it sublimes to a fluorine that is abrasive. Also, PTFE can not
> physically penetrate metal.
>
> Using a dry film lubricant on other engine parts - ok on some parts. I
> worked with Chrysler on their NASCAR motors as they started back into
> NASCAR. They were looking for a dry film lubricant for the piston skirts.
> They were having wear problems. A DFL was selected - would not tell me
> which one - I think it was Teflon based -most candidate DFLs were. I have
> tested many PTFE DFL's and they do not meet the requirements for space use.
> As a side - In 2000, Nissan started putting DFL on the piston skirts of the
> VG motors.
>
> So, putting a DFL on the skirts does help. Putting a PTFE DFL on cam lobes
> and lifters will only last minutes. Combustion chambers -seconds. Timing
> gears - mmm for a while.
>
> I work with DFLs everyday and have given their use in motors and other auto
> applications some thought. The next time I build a motor I will most likely
> put some DFL on the piston skirts. I need to run wear tests with DFLs in
> motor oil to check compatibility with the binder system and insure a good
> wear life.
>
> I think the best think you can do for your Roadster motor is run a synthetic
> motor oil. Stay away from snake oils- none improve wear life. Watch out
> for vendor clams. We have lost satellites because of engineers believing
> faults clams and not putting the product through the right tests.
>
> Have a great Roadster day!! and watch your wallet:)
>
> Phil
> SEROC
I'm going to second everything Phil said. No disrespect to the guys at
Malvern, but this is old and generally discredited tech. PolyDyn has
been around since at least the late 80s (which is when I first looked
into them and other DFL suppliers). Back then they gave you lots of hard
technical info and were more of a general contractor as opposed to an
automotive oriented company. In fact at first they said little about
automotive applications. But they did go into detail about their process
and how it differed from any other DFL products/services available.
Their biggest competitor in the auto field was a company hawking Moly
coatings. The moly guys were slicker, better sales people and promoted
the heck out of their products and services and seemed to be about to
make it big. PolyDyn sort of disapeared back into industrial and
(supposedly) aerospace work and sort of let the auto market go. Back
then they didn't offer anything but DFL products/services. From what I
am seeing now, PolyDyn has either changed hands or has taken on a new
approach to marketing. They are targeting the auto market again, and are
into the snake oil market as well.
Back in the day they were a good company with a product with limited
appliations to the automotive market. Despite their claims, theyir
products were only really effective in a limited number of applications.
And they never really lived up to all the claims they made. Now they
look like another Slick50 outfit, and I would have serious reservations.
As Phill said, and as DuPont has gone to court over, TFEs in motor oil
are not a good thing, no way, no how. Only one company ever developed a
process for using TFEs in motor oil. The big problem they had to
overcome was that the small TFE particles want to coagulate together
into big particles, which then end up in the filter doing nothing but
clogging the filter - if I am remembering correctly it has to do with
the static charge of the particles or something, and this company
developed a way to change the charge or some such thing. They got a
patent on their process, but they do not recommend it, even so. Their
process does keep TFEs in suspension in other less stressed oil
applications, but they too found there are other problems with TFEs in
motor oils used in internal combustion engines. TFE DFLs do work
reasonably well in some applications, but the claims are exagerated by
the companies doing the selling. If you look at the specs you'll find
that there is no way they can possibly do what is claimed. And there is
no way they would extend T chain life by any measurable amount. NO WAY!
The other DFL from back then, moly, turned out to be a real nightmare
and is primarly sold now for DIYers to use at home, because those
customers are more gullable and do not understand the potential
problems. The companies who were about to make it big have all gone
under or scaled back big time. Again, there are *limited* applications
where it is helpful, but the claims put forth by the marketing depts.
were just way over the top. I found out the hard way, just how
problematic some of these products could be. As an experiment, I had a
complete engine treated with the top name moly DFL. We sent them all the
parts they suggested treating, and had them do just the treatments they
recommended and whatever post treatment prep they felt was needed. The
engine lasted 15 mins. YEP 15 f'in minutes. Failure mode? Some of the
moly DFL overcoating (which they told us to leave in place other than
where they had already sucffed it off) flaked loose, got into the crank
passages and clogged the oil feed to a rod bearing. Now remember, their
recommendations, their application, their prep. All we did was assemble
the parts when we got them back from the these guys. I'd never had a
similar failure before or since, and the material clogging the crank was
identified as moly. The only moly used in the engine was their DFL and
the cam lube, which I have used for years, and still use today, without
any problems. They told me it was not the fault of their product, that
it must have been faulty prep and assembly techniques on my part, that
their product could not cause such a failure. They did not want to see
the parts or the test reports. And then they stopped returning my calls
and letters (back before the days of email).
I also tried Polydyn's stuff, though in a much scaled back manner, and
found it did work in some situations (such as piston skirts) but not in
all the applications they were suggesting. If the loads and/or temps
seen in use exceed the product's parameters, it will not work in that
application, no matter what they tell you.
--
Marc Sayer
82 280ZX Turbo
71 510 Trans Am vintage racer
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