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



Would you NOT recommend the RA seals?
Don

That is correct. I do not recommend them. You can buy stock seals
from Mazdatrix or Mears Motors in Lubbock with a discount.

http://www.mearsmotors.com/

Paul Lamar


Paul, based on the exchanges you have monitored, does it appear most folks
are rebuilding their Gen 3 and Gen 2 engines for aircraft with used rotor
housings and as-is or lapped side and intermediate housings?  Aso, has
anybody lately developed a program and machinery for clean-up only lapping
process for used rotor housings?

Steve Beckham

If they don't pass the wear test in the shop manuals  they need to be lapped. Mazdatrix can do it as well as some place in North Carolina. I have never been able to find that address and name yet. It might be this place http://www.grindtec.com/
Or they may know of the right place.

Racing Beat might still do it as well. I know they have a lapping machine.

Here are a few other outfits.

http://www.lapping.com/
http://www.surfacefinishes.com/
http://www.flatlapping.com/sitemap.htm
http://www.askoinc.com/asko/about.asp

The RX8 rotor housings I am getting look to be in real good shape so I assume the end housings are too.

Paul Lamar