Sorry about the blank email. Sometimes I fail to change the format to text
only
Or When is an upgrade not really an upgrade?
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As most everyone knows, I'm always trying to improve my KR.? But much like
building, every little change has a string of unintended consequences.? There
comes a point where sometimes I think things would be much simpler if I had
only left well enough alone.? But I'm getting old, and at the twilight of my
career the governmenet pays me lots of money to do what I do, so I've spent
more than my fair share on my KR finding out what works... and what doesn't.
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Three years ago, the tired old cylinders on my O-200 just gave up.? The
compressions were way off and I had been nursing them along for many hundreds
of hours, so I decided to install new cylinders, and while I was at it,
installed the 8.5:1 pistons for an O-200-D.? I had heard those pistons weren't
readily available, so I was quite surprised when Aircraft Specialties said they
had them and could replace the pistons in my cylinder kits with the higher
compression pistons.? Great! (I thought).? I got the new cylinder kits, did
some minor port clean up in the cylinders, and went to put the engine back
together.? That is when I discovered that Continental had changed to a tapered
ring for the higher compression pistons.? No problen, I call Aircraft
Specialties to order.? To their surprise, they couldn't get them.? And if they
could, they were unaffordably expensive.? So I take my new pistons off to my
friendly machinist and had him cut the top ring groove to fit the old style
O-200 ring, and installed the pistons with the much less expensive rings.? That
has turned out to work just great.?
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At the same time I did the top overhaul, I pulled my relatively low time
magnetos off, sold them and bought a pair of P-mags.? After all, the P-mags
only have one moving part, so what could possibly go wrong?? At 65 hrs, I had
an edge connector on the PC card in one of the Pmags simply break.? I was a
couple of hundred miles away from home on an overnight trip, so turned back and
flew home with 2 cylinders not firing on one ignition system.? Emag was very
good with their service and repaired the unit at no cost.??
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The first trip to the KR gathering following the top overhaul and Pmag upgrade,
my generator failed with what was clearly worn out brushes.? I guess they just
wear out every 700 hrs or so.? Breaking down away from home is not only
inconvenient, but a bit expensive.? What would have cost me $10 for a set of
brushes at home ended up costing me $500 for an overhauled generator and two
extra nights at the Holiday Inn in Mt Vernon.? The guys at SRT in Mt Vernon
were kind enough to let me use their tools to change out the generator and
didn't charge me for the shop time.? Man it would have been much less expensive
if I had an alternator on this plane as they are usually good for the life of
the engine.? So I promised myself I was going to upgrade to a new alternator
before this generator needs brushes.
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I also had an older Delco pull cable starter.? With the higher compression
engine, the old inefficient starter, and the light weight Prince Prop, when the
engine would pass the compression stroke on a cylinder while turning on the
starter, the prop would outrun the slow old starter causing the sprag clutch in
the starter to release, then as the engine hit the compression stroke of the
next cylinder, the clutch would grab again with a bang.? Yep, I creamed the
sprag clutch in my starter... twice... at $350 a pop.? Ok, I promised myself to
upgrade the starter as well next time I have money to burn and get serious
about work on the KR.
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Now we are three years and 160 hrs down the road from installing the Pmags and
high compression pistons.? My second starter clutch is failing.? On the return
trip from the spring fly-in at Casa Grande, AZ, I apparently flew a good
portion of the trip with one failed Pmag.? Turned out to be the same Pmag as
what failed before.? This time the head of the Pmag was flopping around loose
on it's mounting flange.? Emag explained to me there are 4 screws that hold the
head onto the mounting flange.? Apparently they had failed to torque them
properly 100 hrs earlier when they had repaired this unit.? So I was going to
be down for 2 or 3 weeks while the Pmag made another round trip to Emag for
repairs.? While I was dealing with that, I found someone that had just removed
a low time Plane power alternator and B starter from his C-85 and was willing
to part with them for a reasonable price.? Hot dog!? Now I can fix my starter
clutch problem as well as replacing the generator with a much more reliable
alternator.? That, of course required some wiring upgrades for the higher
current output of the alternator, but I could finally retire the generator.?
One concern was that the alternator can put out up to
