Greetings Paul,

  I received the taps today, thank you.

  I do have some questions about the mounting of the water block for the
  RX8, most of which I think I know the answer to.

  I assume that I am to extract the studs holding the original
 housing and
  replace them with bolts. Any idea of the thread in the case that is
  used? Can I just double nut the studs and extract them, or do I need
  heat or other methods?

  Since two of the bolts will go through the water passages, will the
  gasket be sufficient to prevent leakage around them. Should I use
  locktite or other thread sealant with them?

  Should I use lock washers under the heads (I assume that they will be
  Allen bolts.)?

  Any idea of the torque values for these bolts?

  I assume that I will use the sealing washer that was under the banjo
  bolt for sealing the taps.

  Is any of this correct.

  Happy holidays,

  Rich

  No on the threads. Here is the drill. Remove the studs and find
  a metric nut that fits. Then take the nut with you to the hardware
  store to find an internal hex head screw that fits. Metric screws
  are a problem as there are three common threads for each diameter.
  It is hard for me to tell them apart by just looking at them.

  The gasket should be sufficient but Mark S can fill us in
  as his is working I think.

  I would use lock tite on the threads. I don't know the torque
  rating but it should be not be hard to find that on google.

  The screw diameter is 8 mm.

  Double the nuts and they will come out no problem.

  Paul Lamar

 Paul,

 I tried making a gasket from gasket material... and it leaked. I made
 another one... and it leaked too. So, I purchased a metal gasket from
 the local Mazda dealership and it worked.

 As for the bolts, one is outside the water passages, and the other two
 bolts fit inside the water passages and are covered by plugs (which need
 sealant).

 Mark

  Thanks Mark,

 I thought I would use those threaded holes for temperature senders
 (inlet temp and outlet temps) instead of plugs.

 Rich


 Good idea Rich.

 Paul Lamar


I put the engine coolant temp sender in the upper hole.  The lower hole
was too close to the slide throttle to use anything but a plug.
 Besides, the lower hole is the coolant return.  I don't really care
what the return coolant temp is.

Mark

I care :) If one knows the temperature drop across the heat exchanger
one knows how well it is working. One could drill a hole in the
bottom of the block for a sensor there. Also it is very very good
to know the pressure in the cooling system. The preflight for
the cooling system is; pressurize it with a hand pump and watch
the pressure gage. If the pressure gage reading slowly drops you have an
internal or external slow leak. We did this with Perry's rotary
in his Long EZ out in Palm Springs and finally, after a couple of days of screwing around, discovered a tension bolt that failed allowing the cooling system to leak internally. The bent bolt was hiding behind the flywheel.

I mentioned the pressurization trick in my book.

I got the idea from Ken Welter used in his rotary powered
coot. His gage reads positive and negative coolant pressure
so as you watch the engine cool off the pressure will
go negative sucking the coolant back out of the over flow
tank. A real education on how cooling systems really work.

There is also room on the front side of the block for more sensors.

Paul Lamar