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Mark,
Do you have TES orings on the rotor oil seals? If so, where did you get them and what were the part numbers?
Thanks, Ken Powell
-------------- Original message --------------
> Dale,
> If I can put my 2 cents worth in here. Keep in mind that we're measuring the
> oil temps as it leaves the cooler and is about to re-enter the engine, so the
> oil gets considerably hotter as it goes through the galleys and is sprayed into
> the rotors. So, 210 degrees is the starting point and the temps go up from
> there until the oil finally reaches the cooler again. Is anyone measuring the
> oil temp leaving the engine?
>
> Mark S.
> (20B with TES o-rings)
>
> Quoting Dale Smith :
>
> > Ed Anderson wrote:
> >
> > > Dale , the problem with oil temps in the rotary is that the oil might
> > > be able to stand considerably higher temps (particularly the synthetic
> > > oil as you point out), but the engine suffers.
> > >
> > > At least with the older and earlier 13B blocks, overheating could
> > > and did cause damage at a temperature range far below where you would
> > > have to worry about the oil decomposing. Overheating apparently caused
> > > the seals to "chatter" against the housing as well as reportedly
> > > "shrinkage" of the aluminum rotor housings. The guidelines were a
> > > maximum of 210F after the oil cooler for the oil and 180F out of the
> > > engine block for the coolant. Now, we have found that at least with
> > > the new blocks the engines will apparently handle higher temps without
> > > adverse effects. Apparently short excursions as high as 240F on the
> > > oil and 220-230F with the coolant can be tolerated without damage -
> > > but, the feeling is that extended operations at those temps is risking
> > > damage.
> > >
> > > The newer blocks seem to be considerably more tolerant of somewhat
> > > higher temps reportedly due to changes in the castings, but I and
> > > others have found to our dismay that exceeding that magic number
> > > (whatever it may be) you do at risk. So that is why you will see more
> > > concern with oil and coolant temps with the rotary at a lower
> > > temperature than would normally cause concern with a reciprocating engine.
> > >
> > > Ed
> > >
> > >
> > > Ed Anderson
> > > RV-6A N494BW Rotary Powered
> > > Matthews, NC
> > >
> > > Steve ... re: the above underlined.
> > >
> > > I would say that what you have is just fine regarding your oil
> > > temp. Remember that the "delta T" between where you are running
> > > and the temperature at where it quits working is quite high.
> > > Especially if you are using synthetic oil. Molbil I keeps
> > > lubricating quite well up past 400 degrees and beyond. Thus, if
> > > you are running temps near 200 degrees you have near a 200 degree
> > > temp spread (delta T) between what the oil can take away and what
> > > it IS taking away in BTU's of heat dissipation in a stable
> > > system. That is a pretty fat safety margin, when you figure you
> > > can run 100 degrees hotter than what you are now and still have
> > > 100 degrees left before lubrication failure is imminent.
> > > Obviously, lower is better.
> > >
> > > Water cooling now is a different story. operating coolant at
> > > temps near 200 while water boils at 212 ... gives you a delta T of
> > > just 12 degrees to play with. I know you can kick it up by
> > > anti-freeze, pressure on the system, etc. etc. but the bottom
> > > line is that you have a lot narrower delta T range to deal with,
> > > and you are always working the system a lot closer to near it's
> > > maximum potential for heat dissipation.
> > >
> > > Just a thought,
> > >
> > > Dale Smith
> > >
> > Thanks Ed, I value your insights.
> >
> > I know that seal chatter was an early development problem with the
> > wankel, but thought that Mazda had pretty much made it a thing of the
> > past with modern materials, geometry, and springs. I did not realize
> > that this was a temperature dependent problem, that we still had to deal
> > with.
> >
> > Also, not quite sure what you mean re: "shrinkage of the aluminum rotor
> > housings"? It can't shrink with heat. By this do you mean that, that
> > having exceeded some elasticity limit, the aluminum cannot return to
> > it's original specs upon shutdown once it has been overheated?
> > Wouldn't it thus be oversize? Please explain ... this sure sounds like
> > an "engine killer".
> >
> > Thanks,
> >
> > Dale Smith
> >
>
>
>
>
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