Mailing List flyrotary@lancaironline.net Message #449
From: Marvin Kaye <marv@lancaironline.net>
Subject: Re: reliability issues...
Date: Mon, 28 Oct 2002 19:11:39 -0500
To: <flyrotary>
Posted for Mr dan ruggirello <dan_ruggirello@yahoo.com>:
Hello all,
I am trying to get comfortable with some reliability
issues before jumping in.

1.  Continuous operation at 6500rpm.  I have seen
references that these engines are capable of long term
operation of 6500rpm.  Anyone have any documention
anywhere that offers insight into this?  I know that
racers rev up to 8500+rpm, but this is short duration.
  Does the rotary have any history in continuous
moderately high rpm use (perhaps as a generator?)


2.  The tension bolt issue.  I have seen Tracy's fix
and talked to Bruce about what the racers do.  Anyone
know if this mid-bolt damping has been effective for
the racers?  I am having difficulty with the vibration
theory.  If the engines primary frequency is 6500rpm
~110hz, my gut feel is that these bolts are much
stiffer than 110hz and that it may have more to do
with overstressing the bolts from thermal expansion of
the block.  Here is what someone on the RXTech board had to say
about the issue:


"Pineapple Racing has a tension bolt alternative that
has proven itself on 6,000 hp engines that get driven
0.25 miles at a time.  That's probably more than I
should say right there and I will deny it if it
gets back to Rob :-) They require machining out the
tension bolt holes in the housings and are used on the
combustion side of the engine. The real problem is not
the tension bolts themselves, per se, but the stress
put on the dowels when they flex/stretch. This solves
the problem in the most overkill sort of way
possible." Not sure I would want material removed from the
housing but I am planning on getting more detailed
information from Rob at Pineapple Racing.

3.  Premix.  I will be operating in AK and am
concerned about what oil in gas may do if it sits
around in the wings in cold weather for a month or
two.  I am concerned that the oil may separate then
congeal and clog the system somewhere.  I thought about the oil injection adapter by PCV Tech
that uses the stock metering pump, but Bruce indicated
that by design, the stock system starves the engine
for oil because of the motor oil/carbon deposit issue
and that premix would likely be better since you could
increase the oil ratio if you are using 2-stroke.

Any thoughts?

Thanks,
Dan
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