Subject: engine failure rotor weight code
From: ACRE
Date: 7/24/2003, 7:01 AM


"Brian D. Cain" wrote:


An 86 Non-turbo rotor?  I believe they're the same
as the 87
and 88
ones,
correct?  9.4:1 compression?  I'll see what I can do today.
What
weight
code
range do you need?

B

Brian D. Cain -/- Grand Prairie, TX -/- bdc196@comcast.com

This  note is for Brian Cain.
Hey Brian you made a comment above about a weight code for the
rotor. This sounds like a perfect opportunity to
expound upon our
ever increasing knowledge of Rotary. What weight code were you
refering to? Is there any markings on our engines that show a
weight code? I am particularly interested because it
would make an

inference to matching rotors for building engines
from parts. Can
you enlighten us? Doug Mueller 13BT RX-6
N900DM
Henderson,NV

"Brian D. Cain" wrote:

Hey Doug,

There's a weight code, to five varying degrees labeled
"A" through "E"

(where weight code "A" is the heaviest), stamped to every rotor on
their gear side I believe.  They're difficult to see on a
dirty rotor,

but once you give it the spit 'n polish treatment,
they're plain as
day to see. According
to the factory shop manual, when assembling an engine, the weight
codes
must be referenced.  The rule of thumb is you cannot use a pair of
rotors
where the weight codes are two weights out:  For example,
if you have
a
"B" weighted rotor, and then your rotary engine buddy
down the street
gives you a "D" weighted rotor, they're not supposed to be mated.
But,
if he notices he has either an "A" or a "C" weighted rotor, then
either of
those can be used.  I'm not sure of the difference in
weight between
"A"
through "E" but I believe it's within grams of one another.

The factory rotating assembly is quite well balanced from
the factory.

Aside from the issue of the eccentric shaft not having a centre
support to ride on, the engine can be spun very high up from the
factory (8500+rpm). In any event, make sure you use a weight code
that's atleast within one letter difference, if not the same.

http://bdc.cyberosity.com/pictures/MarioTrevino/EngineRotors1.Jpg

B

Brian D. Cain -/- Grand Prairie, TX -/- bdc196@comcast.com MSN
bdc196@hotmail.com, Yahoo! bdc196, AOL Symajhi, ICQ# 1733105
http://bdc.genxracing.com http://groups.yahoo.com/group/fc3s_org
http://groups.yahoo.com/group/HaltechSupport--


That is very good to know, Brian, I never heard of that
before. If its
in my shop manual I must have missed it. The four rotors I
have are all
stamped "D". If I had to buy a new rotor from Mazdatrix I
wonder what
weight they would provide.

Chuck Dunlap


Chuck,
I just opened the box to the rotor that I was going to send you - the rotor is weight code 'C'.  Do you want this one or do you want to find a 'D' code rotor?

Ken Powell

 
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