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 we 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

 Yes here is some flow data from Al Gietzen and some pictures
 of a water pump dyno we used to measure about 3 HP consumption
 for the stock water pump.
 Paul Lamar

Paul--that was a lot of very interesting testing you did r.e.pumping.

1. Regarding the housing you show, did you make the modification and run in
on an engine?...if so what was the result?

2. On Al's numbers, do you know if he were using an under-drive, over-drive
pulley ratio or 1:1?...looking to see if this  is the rpm shown engine rpm
or water pump rpm?

3. Do you know what pump he was using?  Assuming he was using the standard
three rotor pump.  Did the production 20B's also use Gen III water pump and
turn backward?

Steve Beckham

The housing we made was an exact copy of the Mazda housing so the flow
was the same. The I/O was bit different so it could be remotley mounted.
People don't spend any money on this stuff unless they have to. The
stock pump works well enough.

The 20B looks like the pump goes in the same direction. I have one in the
hangar so the next time I go up there I'll take a look.

I am sure Al was using the stock pulleys for the 3 rotor whatever that is.
It looks pretty close to 1:1.5.
I'll send this to Al and see what he says.

Paul Lamar