This is posted with Ed's
permission received today at 10:38
Got the engine apart yesterday and here is what I found.
The front rotor had two small areas on the front side housing and center
side housing across the rotor from each other near the exhaust area. These
areas showed signs of localized heating about the size of a 50 cent coin
(presumably from friction), it appears the metal got hot enough to cause the
teflon O ring to be compromised on both housings resulting in the
coolant/combustion chamber leak.
The question of course is what caused the localized heating, the spots are
near the tips of the rotor - but, the rotor shows no sign of rubbing or
localized heating. Here are several hypothesis that have germinated in my
fevered brain, 1. the rotor housing is somehow narrower in that region resulting
in friction at that point (have not yet measure the housing to confirm or deny
this theory), 2. the corner seals did not move in their holes properly - in
effect were stuck and their ends generated the friction - I would have expected
to see wear marks around the path of the corner seals but do not - of course it
could be that everything stacked up so that they only rubbed at the one
point. Also the rubber plugs were still in the corner seals which I would
think would have been vaporized if it were the corner seals heating
that hot. 3. I also considered that the rotor may not have had the
bearing pressed in properly causing it to wobbly slighty - however, that should
have produced fricton spots at opposite ends of the housings.
Besides, the bearings show no signs of wear (only 10 hours on them) much less
abnormal wear if something were misaligned.
4. Another theory is that the tension bolts were torqued too much on
that side - but, they were all torque to the same ft lbs of torque called for by
Mazda - but, clearly something caused it.
The side housings were new back at my 2001 rebuild of the engine and show
only mimimal wear - well within specs so warped side housings are not the
cluprit.
The rotor housings are brand new and I guess its possible the rotor
housing could be narrower in that region causing the friction, but that is
highly unlikely. Or simply a combination of things..
In any case, what ever caused the friction is probably what caused the
higher than normal turning friction which cleared up after a couple of hours of
running - however, I suspect by that time the damage to the "O" rings had been
done.
So the bottom line, is I really do not know what caused the problem - which
is a bit bothersome. If It were my "screw up" that would be refreshing to
find out, but just don't understand what caused it - stuck corner seals is
probably the best theory I have at this time and its rather weak.
Replaced the fatiqued aluminum brakeline with stainless steel braided
brake hose from Vans and repaired the caliper (removed the "O" ring and aluminum
fittings and replace them), put a new tire on the rim and we now have brakes
again and NO alumimum brake lines. Wheel pant is toast so will
be flying slightly slower without it (the least of my concerns
{:>))
So hope to start putting the engine back together by Thursday and tentative
plan to fly home on Sat or Sunday if all goes well with the test runs.
So Bob, that's about it at the moment. Appreicate all the offers of
help from folks on the list, but really not much to do other than put it back
together. I check around the local towns for any Rotary engine shops but
did not find any listed - so pretty much on my own here. But, have all the
tools either borrowed from my relatives or purchased that I need.
My e mail box has probably been overflowing and Marv should just remove my
subscription until I get back. Can not access it from here because
the @#$&% Time Warner screwed up their pass word system just before I left
and their webmail site won't accept my password.
So that's it in a nut shell, Bob. Feel free to post this to the list
and if anyone has a theory, I am all ears. My nephew has taken photos of
the opened up engine and I will post the photos when I get home.
Best Regards
Ed
Bob Perkinson <bobperk@bellsouth.net> wrote:
Ed,
The
list is curious for information about your progress, so am I. If you
just
posted a short message It would start the speculation mill rolling
again.
If there is anything that you think that I could help you with let
me know
and I will do so to the best of my ability.
Bob
Perkinson
Hendersonville, TN.
RV9A N658RP Reserved
If nothing
changes
Nothing changes