Hey Paul, What if anything are people doing with the pipe that comes off
   of the engine to the interior heater core. Are we to plug that and if so
   what is a good way to do it? This probably wouldn't be a good place to
   run coolant to a surge tank or would it? It's location is pretty high on
   the engine and then it could be circulated back to the rad. Am I
   thinking the wrong way or what?

   BTW, I have my engine sitting in the mounts on the aircraft. Working on
   ignition, exhaust and cooling. I hope to be "making smoke" in the next
   couple of months.

   Thanks,
   Rick in Alaska

   That is essential as a breather tube to the top of the
   pressure tank. That is the only way to get trapped air and steam
   out of the engine in a nose high attitude.

   Paul Lamar

   Rick
   Are you meaning the approx 5/8 inch line out of the left rear of the
   engine that would go to the heater core.
   I'm wondering if Paul is thinking you mean the small outlet on the
   top back of the engine!
   This originally went to the throttle body from memory and is
   important I understand in getting trapped gasses out of the block.

   I've just blocked the heater outlet with a rubber plug at present
   for initial starts but was wondering the same thing.
   I think others have pulled the tube from the block and
   tapped and plugged the hole.

   Steve Izett
   Perth West Oz Renesis Glasair SII RG

   I'll see you in a couple of weeks Steve. I'll bring my camera :)

   Paul Lamar



   Look forward to meeting up Paul

   Steve Izett

   Be careful pipe tapping those cast iron housings.
   It gets real expensive if you crack one. 1/4 pipe is max
   for the top vent. I don't have a rear housing here
   so no recommendations yet for the 5/8 side port to the heater.
   Just use the smallest pipe tap you can get away with.

   Paul Lamar


Hi Rick

I’m just remembering that Ian here in Perth has a 6 port Renesis in his
flying RV7.
From memory he did not remove the steel tube pressed into the housing,
but tapped into the end of the tube itself finding it to be thick enough.

Steve Izett