jim mederer wrote:

Hi Paul,
I believe there is no reason not to use synthetic oil
in a rotary engine except price.  However, there is a
serious potential compatibility problem, and that is
the reason Mazda does not recommend synthetics.  I
have seen instances of "seal swell" when replacing one
oil with another (the same thing happens with some
brake fluids).  This can affect either the front and
rear seals (external leak) or the o-rings inside the
oil seals.  Since they have no control over the oils
and limited knowledge about compatibility in all
circumstances, their surest position is "don't mix" -
which means don't use synthetics.
    Regarding the oil seals, even the smallest "flat"
at the hard chromed edge can promote consumption.  We
always change the seals at rebuild.

                      Sincerely,
                      Jim Mederer

I think teflon seals should stand up well to synthetics. Teflon is very
inert to almost all chemicals.

BTW I have been soaking a stock green Mazda oil O-ring in Exxon turbine

oil

for two months with no noticeable changes so far. I think it is silicone.

I have some Mobil 1 so I will start soaking it and a black one in that.

Paul Lamar

William Shaffer wrote:

ASK MOBIL ABOUT AV1 THAT THEY HAD OUT A FEW YEARS AGO THEY HAD TO REBUILD

A LOT OF AIRCRAFT ENGINES BECAUSE OF THE OIL FALURE. I WILL USE 20-50 RACING
OIL AND INJECT MARVEL MYSTERY OIL FOR TOP OIL  BILLSHAFFER

We tested some Marvel Mystery oil and it was the worst as far as heat breakdown
was concerned. At 500 degrees F it turns to pure gunk. Not what we need
in a rotary. The rotary has unique needs totally unlike any piston engine.

Paul Lamar

The Aircraft Rotary Engine Newsletter.              Powered by Linux.

http://home.earthlink.net/~rotaryeng/            http://www.linux.org