Paul,
       I'm just starting the disassembly / inspection of my 20B for the
   purpose
       of an aircraft conversion.  The thing that seems to be worrying
   me the
       most is the water pump.  That thing is huge, or at least it
   sticks up in
       the air a mile over the top of the engine block.  And....the pump is
       cast iron in an aluminum housing....very heavy!!  Is there some way
       to modify, or preferably another pump that will mount in its
   place that
       will solve these issues?  This thing will NEVER go inside the engine
       cowl?

       Thanks again!!
       Don Mitchell

       No problem. Not to worry.
       I'll give you a step by step on how to cut it down with pictures. I
       did one for Bulent and his is working and cooling fine. Later today.


       Paul Lamar ...No rotor no motor.


   Don,
   If I can jump in here with a comment or two.  Yes the 20B wp is big and
   heavy.  I'm in the process of converting my 20B to accept the much
   lighter Renesis front cover and wp, saving 6# and get the better CAS in
   the process.  There is one bolt that will have to be drilled &
   tapped, but that's the only mod that I could see.  If you don't want to
   change the entire front cover, you can cut the wp section from
   the Renesis front cover and just use the wp section on the 20B.  Since I
   wanted the newer style crank mounted CAS, I will be using the entire
   Renesis cover.  The coolant inlet/outlet on the Renesis is better
   suited for a/c purposes.

   Mark S.
   Lancair ES - N/A 20B

   Not so fast guys. The 20B impeller is a much better design
   than the RX8 impeller. The RX8 impeller is the same as the
   third gen. I think Mazda re-designed it for low average power
   street  car use to cut the WP power and improve the BSFC
   slightly. It seems to work on Tracy's RX8 2 rotor engine.

   Before I did something like this I would install a CHT
   sensor near the lower spark plug on the front rotor housing
   (tractor 20B powered airplane). Cooling wise the front end
   housing is the least well cooled. Particularly on the 20B.

   Paul Lamar ...No rotor no motor.



Paul,
Yes, I did the CHT mod as shown in ROTOR_HOUSING_THERMOCOUPLE.JPG when I
had my engine disassembled and installed a thermocouple in each rotor
housing.  So, now I can monitor the temps as you advise.  Does anyone
know the flow rate of the Renesis wp?

If I recall correctly, Tracy is running a Renesis wp on his RV-8.  Since
he hasn't flown (that I know of), we'll have to wait a little longer to
find out how well it cools.

Mark Seitle.

(we got two Mark S's )

Great Mark. I know you have not flown yet but what kind of numbers
are you seeing so far?

Please fly with the stock pump. We need some base line CHT data.

I don't have any data yet on the flow rate of the RX8 water
pump. The second gen are 30 gallons a minute.