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Hi Bill,
I am a proponent of "if it ain't broke, don't fix it." if you have some
history with the mechanical device in question. On the other hand, when
that history is unknown, not knowing can bite you.
I bought a "Brand New" 13B - trouble was it had a bit of water in the
coolant jacket, which corroded the iron castings. Everything in oil looked
brand new. The coolant passages were another story, after bead blasting the
coolant passages until they were clean I did a bit of destructive testing on
the castings with a dremel, just a bit because they looked fine... a minute
later I was pretty dissapointed, went through like butter in some places
( like near the coolant o rings), just turned into black dust. $1500 later
I think I have an engine that is as good as it is going to get.
Don't be put off working on a rotary, these engines are easy to work on, buy
a couple of good torque wrenches, a box of sandwich bags, a sharpie, take
pictures as you go and take your time - try it out on a junker 13B the first
time to build confidence.
Even factory rebuilds have the occasional issue - I apprenticed at a Porsche
/ Audi dealership. I witnessed a $25,000 (1980 dollars) 3 litre 911 long
block throw a rod in the first couple of minutes after start up, missing
connecting rod nut on one side of the cap - sh!t happens.
FWIW
Ian
-----Original Message-----
From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net]On
Behalf Of Bill Dube
Sent: Monday, June 06, 2005 1:53 PM
To: Rotary motors in aircraft
Subject: [FlyRotary] Un-touched engine (was: EC2 problems - solved /
rotary risks)
I'm reading between the lines of Al's posts but it seems that he is
emphasizing the importance of leaving the engine as un-touched as
possible. I once wrote an article for Light Plane World (EAA's ultralight
magazine back in the late 80's) and advocated the same thing after noting
that many Rotax failures occurred soon after the owner opened up the
engine for maintenance. Decarboning the piston ring grooves was important
but many builders were causing more problems than they fixed when they
went inside so I recommended some products and procedures that would do
the job without opening the engine.
This is the exact reason that I would prefer to not open up my
RX-8 engine.
I plan to borescope it and compression test it and inspect it in
every way I can without taking it apart. If I don't find anything wrong (or
suspect) during these inspections, I plan to run it "un-touched" internally.
There seems to always be something that goes amiss when you
disassemble and reassemble an engine. A prime example is the thick front
cover gasket versus o-ring problem.
There is a lot to be said for, "If it ain't broke, don't fix it."
Bill Dube'
Homepage: http://www.flyrotary.com/
Archive: http://lancaironline.net/lists/flyrotary/List.html
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