Hello Readers, I'm a new subscribe. I've been reader the archive for a
couple months now.

What's my story?
Well I have a Wag-Aero 2+2 which originally flew with a 3.8L Ford V6; got
about 20 hours out of the engine and 3.5 flight hours before experiencing
engine misfires ... turned out to be a broken valve keeper which caused the
rocker arm to chip a piece from the head. I loved the Ford but due to its
excessive weight decided to rebuild an inherited Mazda 13B engine instead.

The rebuilt engine has been running on stand with EC2 and RD-1C. Engine is
now hanging on the airframe and I'm rewiring everything for final
installation.

I have a question related to the original Mazda heater core configuration:
How was it connected? There is a 5/8 or 3/4 water connection on the rear
iron but there is no mating connection anywhere. The water pump has a small
3/8 connection that feeds into the original intake system. Was there a "Y"
in the water pump outlet to radiator or what?

Jeff Whaley