> Hi Tracy and all,
> You wrote:
> 1.  Coolant feed to stock intake manifold.  On an aircraft installation,
> this MUST be vented to vapor collection point.  I would suggest a fitting
> screwed into points 5 or 6 for this.  5&6 are otherwise not needed for our
> use.  Ignore or plug.
>
> Please, explain why #1 MUST be vented, and what you mean by a vapor
> collection point.  I have #1 tapped and plugged at this point...
> Thanks for more understanding!
> Tommy James<><

Because if not vented here it is very dificult to purge all the air from the
block.  This is especially true on taildraggers.  It's not impossible (to
purge the air) but it is difficult enough that it has caused more than one
engine to be overheated to the point of needing an overhaul.

The vapor collection point is usually the highest point in the cooling
system, the waterpump housing in our case.  If you have a higher point in
your system, us that.
I tapped that connection in my engine as well.  Screw a hosebarb adapter
into the hole and run the hose to the high point of system.

Tracy