I think I found the reason for the over heating I wrote about some time
ago. I appears to have been the result of my own ignorance. It appeared
to me that the reason for the local overheating must be somewhere in the
coolant flow. I think, one of the responders to my previous report
mentioned that possibility.


What it boils down to is the fact that not all the cooling pockets in
the rotor housing are open to coolant flow. In particular, the second
opening on the inlet side is totally blocked off by the side housings. I
left it open, and worsening the situation, there is a comparatively
large hole in the rotor housing web. As a result, most of the coolant
did go through this opening, and not through the area around the plugs.

If I had looked close at the flow pattern from MAZDA this problem could
have been avoided.

Fortunately, there is no permanent damage to the engine, and the engine
in the airplane has not run yet. I fixed the problem by closing off the
opening. The engine is now going back to the test stand for another 10+
hrs of beating.

Richard Sohn
N2071U

Randy, You need to check yours for this.

Paul Lamar