These are not needed for most aircraft. Van's RV's usually have plenty
of room over the top of the engine for a stock 2nd gen water pump.
The RX8 pump is automatically low profile if you do away
with the thermostat housing.
The KIS cruiser has the lowest cowl top of any
aircraft I have run across so far. A low profile
water pump is needed. Fortunately I had one lying around.


Paul Lamar