Hi Dale, The best used engine I ever bought was a fire damaged engine that looked just like you described. I'm still using it for development on my test stand. It was so good I didn't even bother to overhaul it (but I would before putting on a plane) The resistance you felt may have been due to carbon lock from a piece of carbon deposit falls off the rotor and gets jammed. I doubt you did any damage to it if that was the case. Your questions about the lower manifold are covered in detail in the book. Forget the barrel valves in aircraft applications. There is no loss of "low end performance" that you will ever notice. Tracy Crook ----- Original Message ----- From: Dale Rogers Sent: Wednesday, February 18, 2004 5:21 PM To: Rotary motors in aircraft Subject: [FlyRotary] My "new" engine Hi All,
Well, I got my "new" engine cleaned off, and I've begun to
disassemble it. I got a bit of a surprise after I washed off the
engine-degreaser softened layer of dirt. The engine had been in
a fire. Good thing I only paid $200. Still, it doesn't look
like the fire was very widespread or last very long. Most of the
damage is localized around the throttle body. One thing I missed
during my original inspection (besides the signs of a fire) was
that the secondary injectors had been removed and plastics plugs
inserted. I'd bet those add up to more than $100 (sigh).
As you may be well aware, I'm a "greenie" about rotaries.
I've tried to soak up as much knowledge as possible from this
list and from forums like www.nopistons.com/forums/ , but now
that I actually have an engine to work on, I'm finding that
there are a lot of things about it that my Chilton manual simply
doesn't cover. So I have a lot of low-level questions. Perhaps
y'all can save me some time, and give me a pointer to a really
comprehensive manual on the 2G engine? Or maybe, everything I'll
actually need to know is in Tracy's book, and I can just throw
away anything I don't see mentioned? (Tracy, a money order will
be on it's way Thursday.)
My immediate concerns are: (1) the engine turned over fairly
easily for 20-30* of arc just hand-on-belt-pulley; with a wrench
it went through ~two turns then started binding; guessing that I
had an apex seal stuck high, I backed it up, squirted WD-40 into
intake and exhaust and started turning forward again; after
several iterations of this, I succeeded in getting it to turn
indefinitely. Did I do any harm turning it backwards?
(2) I can hear the "whuffs" of compression/release, as I turn
the eccentric shaft, even if I turn very slowly; but I can't
*see* anything through the exhaust port that *looks* like a seal.
I know two mm isn't much, but ... ??
(3) The cause of the engine fire; there is a small amount of soot
on the inside of the throttle body, but that could have been from
someone opening it after the fire had started. How can I play
detective here, before I've destroyed the evidence by disassembly
/cleaning?
(4) Extent of damage from fire - primary injectors are sooty, but
no obvious distortion; that's more than I can say about the
injector connectors, I don't think I can get them off without
destroying them. How likely is it that the injectors survived
the heat? Will a leak/flow test be adequate to vet them?
Same-same for the oil injectors; tubing to them is melted away,
except the last six or so inches above the OMP.
Not immediate, but I'd like to start working out a solution:
the induction system - a six-port is going to be more of a
challenge than I originally thought. My original plan was to
keep the stock throttle body and maybe the manifold adapter(?)
that bolts to the housings. The adapter is far more complicated
than anything I've seen on you folks' sites. Then too, losing
the barrel valves looks like it will hurt low speed operation
(a lot?) _unless_ I can isolate them to a secondary throttle
channel. Trouble is, the stock throttle works just the opposite
of what I would have thought, from just looking at the picture -
the double bore is the primary. I know, I should only need low
speed while taxiing and descents; still, I don't want the engine
sputtering on the ramp. Over on the canard-aviators list there
was a long thread about "GIB" fear, and I was thinking that, once
I get things to the point where we can actually fly together,
having an engine sputtering just before takeoff would not do
much good for my spouse's confidence.
All the alternative TBs I've heard mentioned (except, maybe,
using Webbers as TBs) are single control. I suppose I could
press an old AFB carburator into service as a TB only, but I
have a feeling that I'll be in for a lot of fun getting things
like a TPS to work with it. What have I overlooked here?
BTW, my "complete" engine (full intake, and exhaust plenum -
no accessories, like starter or alternator) weighed 235 lbs. on
m 250 lb. shipping scale. Does that sound about right (or do
I need to get my scale recalibrated)?
Thank you all, for the knowledge imparted already,
Dale R.
COZY MkIV-R #1254
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