snips..
Hi Royce;
Here's some of the scoop on Mobil One from my files.....
If you need more info let me know, I may have more on
Synthetic Oils.
Butch
What do you think Butch. Why does Mazda say no synthetic oil?
Opps forgot Butch's zip file.
Here it is.
Paul Lamar
Paul
I read the zips.
Not much new there but thanks anyway.
The reason we asked the original question was we wondered why Mazda, as well as
most other MFG's recommend against synthetics.
For years I have used synthetics in aircraft engnes, jets, turbines and recips.
That was all military machines. I believe it was about '62 when we switched and
never looked back.
I am going to run synthetics in my rotary's. I will also use a modified
injector pump to pump 2 cycle oil from a reservoir and not the engine sump.
However, that may be a moot point.
Modern synthetics are a much better oil than they were even a few years ago.
They still will have some additives that aren't present in 2 cycle oils.
Since 2 cycle oil is designed to be burned it may well be the best way to go to
lube the apex seals.
Synthetics do a much better job of lubing than mineral oils. They are naturally
slicker without the extra additives, so they will go further between changes. It
will be interesting to see the results on my dyno.
Here is what Racing beat says about synthetics in their tech manual.
Oil Selection
The Mazda factory does not recommend
the use of synthetic oils in their rotary
engines -specifically addressing this issue
in the "Owner's Manual".
In 1979, Racing Beat began testing syn-
thetic lubrication products. Without a
doubt, the best synthetic oils do perform
well in extreme heat (over 300° F) and
extreme cold (below 32° F), but by the
nature of Mazda's rotary engine, the oil
temperature never exceeds 250° F without
severe engine damage due to other factors.
In Southern California, we have difficulty
seeing the low-temperature benefits: how-
ever, when we put synthetic lubricants in
the engine, transmission, and differential in
our IMSA GTU race car, we immediately
saw what we later found to be a common
result: The oil temperature in all three loca-
tions dropped 5 to 10° F for the same oper-
ating conditions. This is apparently due to
two factors: reduced friction between slid-
ing surfaces, and reduced foaming. As we
continued to use synthetic oil products it
became clear that they genuinely reduced
wear. We also found benefits in street use.
On two occasions, cars with "scratchy"
transmissions synchronizers were completely
cured by a change to synthetic gear lube.
After many years of experience with these
products we have observed only one
"problem": because of the reduced friction,
the time necessary to "break in" an engine,
transmission, or limited slip differential
(standard differentials are no problem) is
excessively long, so we recommend using
mineral oil in all three for a time to ensure
rapid "break in.
Royce
I was concerned on what effect, if any, it had on the oil O-rings.
So far nobody has said anything about that?
Paul Lamar
Paul
We converted numerious engines from mineral oil to synthetics. The early engines had
to have the "O" rings and lambryth seals replaced to be compatable with the synthetic.
That was in the '60's. The "O" ring material back then would get soft in synthetic.
They were made of butyl rubber as I remember it. Either way the rubber composition
was not compatable with the synthetic.
Modern rubber based rings/seals use a different composition. I don't believe the
newer compositions will deteriate in synthetic. ( where's my proof? automatic
transmissions. manual transmissions used by GM. They can use mineral or synthetic.)
If you want to see some effects of the synthetic on the oil seals, put them in a pan,
cover with Mobile uno, heat to 275-300 degrees in your tempering oven for an hour.
If they are still pliable afterwards then you should be ok.
Royce
That is what I was afraid of with the 83 RX7. I might have to tear it apart
and replace all the O-rings with teflon (TES).
Paul Lamar
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