Paul,

 Thanks for the coolant flow rationale.
 Currently the Mazda pump pulls coolant from the rad and pushes it into
 the
 driver's side water passage per the info that you stated.  The coolant
 comes
 out of the block on the passengers' side and goes to the radiator.

 Would it be possible to place a stand alone  pump inlet at the outlet of
 the
 block on the passengers's side and push the water through the radiator
 then
 back into the block inlet on the driver's side?  The flow would be the
 same.
 The down side would be that the pump would see the hotest coolant.  Are
 there other issues?  Thanks for any help.

 Joe Berki
 Limo EZ

 You might get just steam from time to time.

 If you are mounting the remote pump down low that
 is the best place. If the water level is down the water input
 to the pump will still work.

 Paul Lamar



 Paul

 I believe you mean 'low' as in lower than the water reservoir tank
 level.
 Right?  That makes sense.

 Joe,  The issues of increasing the flow rate are  mostly related to
 plumbing
 restrictions and water density.  Pumping the off gassed  cooler water that
 is
 taken from  the bottom of the  vertical reservoir tank after exiting  the
 heat exchanger will be the coolest and hence most dense water.  Pumping
 higher density fluid will result in the best flow rate. Decreasing flow
 restrictions in the externals will increase flow.


 Pumping into the engine block first (like Mazda designed it) will
 subject
 the heat exchanger to less internal pressure then the vice versa route.
 Gentle angled  curves entering the inlet and outlet of all devices  will
 raise flow rate.One sharp elbow can cut the water flow almost 5%.
 Other
 than cutting the cooling grooves in the rotor housings ala Racing Beat,
 we
 can't do much  to improve flow characteristics of the engine, though I
 wish
 the cool water inlet was less turbulent.A 'once through' heat exchanger
 will flow much better than a dual pass heat exchanger and subject the heat
 exchanger to less pressure.

 Here is a good blurb about water heat exchangers.

 http://www.stewartcomponents.com/tech_tips/Tech_Tips_5.htm


 Doug in Japan.


 Doug,

 Thanks for the info.  I believe I can mount the remote pump low on the
left
 side and move the alternator to the right side.  The problem with the
 Toyota
 pump and most of the scenarios that I can come up with involve elbows and
 restrictions such as the pump out let being smaller diameter creating more
 restriction.  The ironical thing about the block that I found to permit
 remote mounting is that it was used for a Stewart EWP in a car.

 Joe Berki
 Limo EZ

 http://www.stewartcomponents.net/Merchant2/
 merchant.mvc?Screen=PROD&Product_Code=E389A&Category_Code=ElectPump

 Stewart is a high integrity company so they make no ridicules claims
 about the suitability of their electric water pumps. To do so would
 ruin their reputation among major car manufactures in the world.
 Their electric pumps are designed to supplement the mechanical
 pumps rather than replace them. Do not use them stand alone.

 It takes about 3 HP to pump enough flow through the Mazda engine
 to cool the metal in the rotor housing at sustained full power.

 Electric pumps are far lower in HP.
 It works in drag racing as the engine only runs at full power
 for just a few seconds. Some drag engine do not even use cooling
 systems for that reason.

 Each HP requires 60 amps out of the alternator.
 To my knowledge no electric pumps come even close. There are no
 breakthrough impeller designs that would change this situation.
 In fact on the contrary some electric pumps have a less
 than optimum impeller design.

 My late rocket scientist friend Vance Jaqua built a 5 HP
 electric motor dyno to test water pumps.

 The physics has not changed.

 Paul Lamar


 Joe, Just an afterthought. With a remote mounted pump it would seem like a
 great time to switch to parallel cooling off the center housing rather
than
 the stock series arrangement. Jeff Doddrige has such a housing and might
be
 open for some pre production field testing.

 george grimes

George,

 I was looking at the center housing the other day and came to the
conclusion that the oil cavity on the hot side would make it difficult to
pull the two different levels of water flows of water out.  In addition the
turbo charger, exhaust and intake manifolds monopolize the real estate
there,  I would be real interested to see how Jeff did it without  a special
housing.

True the four rotor engine uses central water injection but then water  has
to travel through  two rotor housings.  I really wonder with a 13B if it's
really worth the trouble.  It may mess up the  known flow dynamics more than
improve them.   Testing will tell of course.


Doug in Japan



Doug in Japan,   I didn't realize that Jeff has his water connections on
the  port side. That might have to do with how he has designed the front and
back housings internal manifold. I designed mine with tapered end
housing manifolds to equalize flow and connected to the same passages as
Mazda so it would work with stock end housings. I put the water connections
on top because there was nothing competing for that real estate. My intake
runners turn 90 degrees and run towards the firewall rather than making a
180 degree turn over the top of the engine so the top has nothing but the
external water manifolds in that area. I am doing dry sump and the oil fil
and level check are on the tank which is on the bottom of the engine using
the block as the top of the tank.


There is no oil fil extension on the
center housing.Also having the water outlet on top of the block lets any
steam get to the outlet. The water inlet ended up  there because of the
tension bolts and water passages interrupting the available space on the hot
side. It would have required a row of multiple inlets to get the water in
and the supercharger is also located there. Another reason for the top water
connections is when using the aluminum three rotor center housing to make my
four rotor into a six rotor, two rotors cool in series and one in parallel
with it because there is no end housing to turn the water around on the
added rotor. And this requires larger inlets and outlets  which can be done
on the top of the wide housing.



      If Jeff is using some of his intake and exhaust length to get
clearance from the block rather than wraping everything  tight around the
engine block it would seem to leave more than enough space for the water
manifolds. We have 18 inches of intake and 32 inches of exhaust header tubin
so using six inches to get clear of the block seems possible. It would
depend on how the motor mount tubin fits between the intake and exhaust
runs.


I read somewhere that Jeff has a VK-30 Cirrus airframe which is a mid
engine pusher installation and there is generous "under cowl" volume to
space out the engine and cooling components. I am doing a three surface
canard pusher  (Jean Prudomme influence) which also  has an absurd amount of
room for the engine. You have the height of the cabin not just the cowl  and
two feet behind the rear seat to the engine.  In the case of the VK-30 there
is also some tail cone volume since it has a drive shaft back to the prop.
Putting a 79 cubic engine in a space that can accomodate an AEIO 540 takes
some getting used to.

george grimes