>> > Well, we just got the engine from the 87 RX7 apart. We haven't
>> cleaned
>> > up the parts, and it looks like we might not have to - at
least
>> the
>> > rotors and e-shaft. At first glance, it looks like the rotor
>> housings
>> > might be OK. The end and intermediate housings look like they
>> will have
>> > to be lapped & re-nitrided.
>> >
>> > I have attached some pix of the e-shaft and rotors. Looks
like we
>> have
>> > had a coolant and/or lubrication failure. What do you guys
>> think? I
>> > think the e-shaft is junk.
>> >
>> > Can the Babbitt be replaced in the rotors or are they a total
>> loss?
>> >
>> > Good thing I have three more engines on the way. :)
>> >
>> > Doc Custer
>> > Retired Software Engineer and sometime Audiologist
>> >
>> > That is a fine looking engine Doc. Somebody ran it low on
oil from
>> > the looks of it. I would polish the front rotor journal
>> > with 600 grit or 800 grit emery cloth and press out the old
>> > bearing shell in the front rotor of course. Check the oil
passages
>> > in the e-shaft and make sure they are not plugged up. From
what
>> > I can see the rotors are in fine shape. Take some more
pictures
>> > of the rotors out of the engine. From what little I can
see even
>> > the rotor housings look OK. If no apex seals are broken
you have
>> > a flyable engine there IMHO.
>> >
>> > Finn Lassen ran his engine up to 10,000 RPM without oil or
load
>> and it
>> > seized.
>> > He chiseled it apart and resurrected it and flew it for
years
>> until
>> > he mistakenly landed his airplane in the woods at night.
>> > In case you were wondering he was not hurt.
>> >
>> > Have you downloaded the shop manuals yet? I say this
because I
>> > noticed you used the word "babbitt". Real poured babbitt
bearings
>> have not
>> > been used for 75 years. They are now called bearing shells or
>> inserts.
>> > You press the inserts out with a tool that is just the right
>> diameter.
>> >
>> > Depending on how deep the wear marks are in the end housing
>> > you may not have to have them re-nitrided. It tells how to
>> > check them in the shop manuals. All you may need is a bit of
>> > re lapping.
>> >
>> > Paul Lamar ...No rotor no motor.
>>
>> Good news, indeed! I/we are greatly cheered. The guy in the
pix is my
>> grandson David. He and his dad, Ken, are coming to SNF with me.
>>
>> We have the shop manual.
>>
>> I used "Babbitt" because that is the term Bruce Turrentine
uses in
>> the DVD
>> on how to overhaul the 13B. I will no longer use the obsolete
term. I
>> promise. :)
>>
>> BTW we will not arrive until Friday PM. I hope you will be
around
>> Saturday
>> and Sunday. We leave Monday.
>> I definitely want a copy of your book.
>>
>> We are in the process of finding a tank big enough for the
rotors.
>> As soon
>> as we get the rotors and other parts cleaned up I will send
more pix.
>>
>> Doc Custer
>> Retired Software Engineer and sometime Audiologist
>>
>>
>> I'll be there on Saturday but every body splits Saturday
>> night or early Sunday morning. Better to get there on Thursday
>> or Friday. By Sunday morning a lot of airplanes are gone
>> and the locals come for the airshow.
>>
>> Paul Lamar ...No rotor no motor.
>>
>>
>>
>> I have a 20 gallon parts washer that is sitting around, Doc. Plenty
>> deep for the rotors. If you have a burning desire to fly/drive up
>> to the Springs you can borrow it for as long as you like. Maybe
you
>> could come up in a weekend or two when I'm ready to fire up the
>> engine again.
>>
>> Mark Supinski
>>
>> Mark Supinski
>
> I/we would love to come up and chat awhile. Just let me know
when. The
> only
> weekend scheduled so far is SNF.
>
> What kind of parts washer?
>
> I have a small parts washer - the pump kind that you put kerosene or
> mineral
> spirits in and brush the part. What I really need, and am looking
for,
> is a
> tank with carb cleaner or some other degreaser chemical that
won't eat
> AL or
> copper or whatever the inserts are made out of. We are currently
using
> one
> of those one gallon cans of carb cleaner with a basket that you
can soak
> small parts in. The rotors and housings won't fit in it, and whatever
> chemical cocktail is in it does a terrific job of getting the dirt,
> grease
> and carbon off; makes a long job much shorter. We would like to
soak the
> rotors and housings.
>
> Grandson David found a 5 gal tank with chemicals for $90 on the net.
> We are
> going to see if we can get one locally. This might be big enough to
> fit the
> housings in. There is also a 16 gallon one for $407 that is
mechanized,
> i.e., has a mechanical stirrer - but no chemicals. The chemicals are
> $17 -
> $20 per gallon. Ouch! Judging from the pix, the 16 gallon is the
same
> diameter, just taller.
>
> Doc Custer
> Retired Software Engineer and sometime Audiologist
>
>
> You will need some heavy duty cleaner indeed to clean
> those rotors. They are usually a mess. In fact it takes
> longer to clean the rotors than over haul the engine :)
>
> Make sure you press those bearing shells out of the rotors
> first as they are affected by many solvents.
>
> Doc what is the status of the slide throttle parts?
> Are we close to being able to buy them?
> --
> Paul Lamar ...No rotor no motor.
Hi Doc;
Simple green does a decent job on some of the carbon.
Home Depot Zep Industrial purple is even better. I have seen
people get caked rotors absolutely gleaming letting it soak
overnight. Although it also seems to strip the cadmium? plating
in long soaks and is probably not the best for the bearings.
A short 10 minute soak and a quick pass with a brush will get
all but the worst caked on carbon without any apparent damage.
Really hard carbon will require a bit of scraping with an old seal
in some of the grooves and another pass or two.
It can also be done in a small tub/parts bin with just a few inches
of cleaner by just rolling the rotors face by face as you go.
Happy scrubbing :)
Cheers
Cary
I have been told that regular Simple Green is corrosive to Aluminum and
hence not used by the USAF. Simple Green recently came out with an
aircraft version:
http://www.aircraftspruce.com/catalog/cspages/09-00809.php
I suspect that for the application being discussed - cleaning engine
parts, regular Simple Green poses no risk - The parts are massive, and
the cleaner will be thoroughly rinsed after use. I believe the big risk
of corrosion with regular Simple Green comes from using it on riveted
Aluminum assemblies where rinsing all of the cleaner from the crevices
and seams is not possible/practical.
Matt-
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