Paul ,
 One of the rotor housings I sent has a very small chip out of the steel
 liner at the
 edge of the housing.They should be arriving today.
 If you have time would you please take a look at it and let me know if you
 have any
 concerns.
 Thanks,
 Geir

  Hi ,Paul

 Just wanted to confirm my rotor housing's arrived last week.If you could
 let me know
 what you think on the chip , I can round up another housing if nec.

 Thanks,

          Geir

 The chip is not a problem. They look OK. Thanks for cleaning them up.


 Paul Lamar



Paul--Maybe it would be helpful for folks rebuilding with used rotor
housings if you would take a photo of the chip in the housing (and/or  other
other housings) to give builders an idea of what is servicable or not?

Steve Beckham.

That is very subjective. Some of them that look pretty bad will still work.
You may be down on power and torque in the lower RPM ranges. In the upper RPM ranges
it hardly affects the power at all. Urban legend has it if you can get it started it will run without apex seals.

It all boils down to if it will start it is probably OK assuming there are good apex seals in it. I suspect the new apex seals and the housing come to a mutual understanding so to speak.  A bit of wearing in of the apex seal and a bit of wearing in of the rotor housing to a lesser extent.

The vast majority of after market seals on the market do not have the slight crown shape of the stock Mazda seals. My guess is this is 99% of those after market seals. If you check the compression with new rotor housings and the new after market apex seals the compression will be down about 10%.

In one case of after market seals that I know about the housing was scratched with only a few hours of running. For that reason I do not recommend after market apex seals as the surface finish is not nearly up to Mazda standards. The stock seals are heated with a laser and cryogenic cooled. Technology beyond the after market providers. The only exception is the Ianetti ceramic seals. If you buy a set of after market apex seals inspect them with a high power jewelers loop and reject them if the surface is not a mirror finish.


Paul Lamar