Paul--was recalling your "water pump dyno" tests.  In that regard, has anyone bench-tested the flow of the stock and other pumps to measure the actual flow through the pump and engine at various pump rpm?

Everett and I did this during the initial dyno tests in 1988-89.  We could easily do it then because were using the water brake dyno in the beginning...same one we used on competition race car and boat engines.  But those early tests are not meaningful today because we were using a water pump we made cast for the first protype engine.  With the water brake dyno it was fairly easy to check flow.  But when we built a new dyno to test the rotary engines with reduction gear and test club installed, didn't do further precise water flow tests.  We did continuously increase water pump rpm over time as h.p. increased.

Mazdatrix or others who use a water brake dyno may have different pumping outputs by model water pump at different rpm with careful documentation of the overdrive or underdrive ratios due to various pulley combinations?

If those pulley and coolant combinations are not noted, the engine rpm can be misleading. We found this out when working with the Texaco/Dow folks testing propelene glycol in our engines during testing phase prior to sale of prope. They provided us their test results showing it was necessary to overdrive the pump due to different viscosity of the medium. So based on their prior testing with V-8's, and at their suggestion,  we used an overdrive wwe did that right out of the gate and on following engines even when we used straight water and Water Wetter or equiv.  May have been consuming a little h.p. to do so.

Steve Beckham

I'll have to get back to you on this. I am on my EeePC and all my files are on
the desk top.

We made a water pump dyno and at 7000 RPM as I recall it was sucking down 3 HP.

Paul Lamar