OK Paul, another stupid question:

 I purchased one of Tracy's engine rebuild kits for my 20B. It came with
 "competition" Rotor Oil Control Ring Springs and they are color coded as
 follows:

 Qty. 3 - Outer "Competition"- powder blue
 Qty. 3 - Inner - Blue

 Qty. 3 - Outer "Competition"- Ivory (looks yellow to me)
 Qty. 3 - Inner - White


 Is there any easy way to tell where the various colored springs go?
 I have tried to use the info on both the Mazdatrix website
 (_http://www.mazdatrix.com/b3.htm_ (http://www.mazdatrix.com/b3.htm) )
 and
 Bruce's
 video to sort it out, but I still can't figure it out. Tracy's not sure
 either.

 My understanding is that the 20B engine is basically a 13B with an
 additional
 rotor stacked on the front. I therefore assumed that if I initially
 ignore the "additional front rotor", that the remaining rear and middle
 rotors of the 20B would be exactly like the 13b rotor arrangement. Is
 this
 a correct assumption??  I then tryed to use the instructions from the
 mazdatrix website to arrange the oil control
 ring springs on those two rotors in the same manner described for the
 13B.
  When I did it in this manner, I was left with one of each color springs
 to put on the 3rd rotor (the additional front rotor which is unique to
 the
 20B) and this seems odd to me.

 The mazdatrix website states that the front 13B rotor (my center rotor)
 gets the White and Ivory (competition) springs.......thus two white
 and two ivory springs. That leaves one of each remaining since I got
 3 of each.

 The mazdatrix website states that the rear 13B rotor (also my rear
 rotor)
 gets the Blue and Powder Blue (competition) springs.......thus two
 blue and two powder springs, and again one of each now remains since I
 got 3 of
 each colored spring.

 So now I have one of every colored spring left which would make the
 spring

 arrangement very different for the remaining rotor (ie. every groove on
 this
 rotor would have a different color spring.).  It doesn't seem right
 that this would be the case and this is why I'm Asking for help. Where
 did I go wrong?

 Don


 I have no idea. If it were me I would leave them out of an aircraft
 engine all together. Oil scraper rings just cause friction, heat
 and wear. I am in the process of building an engine without them
 to test the idea.

 Mazda had to do it as without them the engine acted like a radial
 engine with oil accumulating in the lower chamber. On start up
 huge clouds of smoke would come out of the exhaust. No worse than
 an AT6 engine however :)

 I had a Cosmo I drove for years with melted oil control O rings.
 No big deal. When it was running there was no hint of oil smoke
 and it did not burn a lot of oil anyway. Of course the scrapper
 rings were still in there. I am having the engine assembled
 without the scraper rings just to see what will happen on
 the dyno. I feel they are not really needed.

 Paul Lamar



 Paul,
 an engine without oil scraper rings will smoke like you won't believe.
 makes
 way more smoke than the navy smoke layers.
 It is easy to figure out the position of the oil ring springs. Each is
 installed so the drag on the seal causes the spring to compress on it's
 self. Installed backwards, they stretch and lose tension, again causing
 smoke and oil consumption.
 Larry

 My Cosmo never smoked when it was running but it still had the scraper
 rings. Just the O-rings were shot. You are the first person that told me
 that and I trust your judgment because of your vast racing experience.
 Dave Lemon did not mention that but he was still reluctant to try it
 without scrapers as he is building the engine. Did you try just one
 scraper ring?

 Have you ever heard of "competition" Rotor Oil Control Ring Springs?
 Are they lower pressure than stock?

 BTW We have built engines with TES oil O-rings and that works fine.

 Paul Lamar


 Paul,
 I have never tried racing springs, nor do I understand the need for them.
 maybe they have less tenstion to reduce friction.
 I have also never tried one seal, If you look at the way the seals
 orient,
 the outer seal is protecting the inner oil seal from seeing any combusion
 gasses that leak past the side and corner seals, so running without it
 may
 shorten the life of the inner seal. To me it is not worth the risk as
 these
 have never caused a failure causing the engine to shut down.
 Larry

 That is true but they do suck some HP due to friction.
 How much oil do they burn in a race situation?
 This engine I am building will never be used other than
 on the dyno. It is strictly for experimenting with such things
 as fuel injection and ignition systems. We will probably tear
 it down more than once.


 Paul Lamar

 Paul, Is this discussion about the flat springs behind the rotor side
 ring
 (gas pressure) seals of which there are three on each side of the rotor.
 The
 dual springs would therefore be 3X2 + 3X2 or 12 springs per rotor which
 would make the spring kit for one rotor and would require three such kits
 for a three rotor engine.

 george grimes

 No "Rotor Oil Control Ring Springs"
 Two on each side.

 Paul Lamar



 Paul,

 See attached from RX-7 repair manual.

 Mark S.


Paul,

Sorry for the "prn" file. Here's a better one.

Mark S.

Yes of course. Those are the stock springs. Don had me fooled
for awhile thinking the paint color was custom. I forgot the stock
springs had paint as well. I also assumed Don had the workshop manual.

Thanks Mark for catching that.

Guys you can download the workshop manuals from
http://foxed.ca/foxed/index.php?page=rx7manual

Paul Lamar