"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.Jp
g

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

Look like a letter difference either way is OK, go ahead and send it.
Thanks in advance---

 Chuck

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