> 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.
I am expecting the prototype parts back from the anodizer this week. I will
take orders from the ACRE newsletter as soon as I can figure out a
reasonable price. (I just found out that the first piece of Teflon was
priced as scrap, so my numbers have to be re-run.) I expect to be taking
orders for the first production run at SNF: I will have at least one of the
prototypes there. As soon as the webmistress gets the web site up, I will be
offering them there also.
RE: pressing out inserts. I see from the shop manual that Mazda has a
special tool for this. Is there a good alternative?
Doc Custer
Retired Software Engineer and sometime Audiologist
Probably have to turn something on a lathe.
If the inserts in there are junk (it looks like that is the case)
you can cut them out. That will buy you a bit of time.
Looks like at least one is. BTW from the looks of
it your engine may have been run at 12,000 RPM not in gear.
That too would cause the rotor bearing to be over loaded.
Paul Lamar ...No rotor no motor.
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