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.
Why not use this for cabin heat?????
Rich

I was originally going to put a heater core in the cabin
and feed the water as per Mazda's design.
I've now planned to install a standard airbox from Vans
with a feed
from heated air post radiator, like Dave Leonard' in
the photo. Can Dave L comment?
In the end weight and simplicity seamed to win for me.
Steve Izett

Guys, I think what is circled in that pic is a fuel
pressure regulator, but
I could be wrong...or maybe that pic was just referenced.
Rick

Your right Rick. It got interchanged with the one steve
sent. Both pictures are the same.
Paul Lamar


Rick and Paul
The photo of Dave Leonard's was to show the heater box
and scat hose.
Steve Izett

I'm wondering if this approach (using the air from the
back-side of the
radiator for cabin heat) will produce air of sufficient
temp to warm the
cabin on a really cold day. Dave is in Calif if I remember
right. I'd been planning on going with a cabin air heat muff warmed by
radiated heat from the exhaust, but this has some negatives (even
though double-walled, CO safety is still a concern. Also, it can
make inspecting the exhaust more difficult).A separate heater
core adds weight and complexity, so I'd like to use Dave's
approach if the air
coming out will do the job when the OAT is -20 deg F.

Mark Waldron

One of our tangential muffler designs made by Jerry Hey
has a tube welded in the center. It helps the muffler quiet
the exhaust as
the gases rub on the tube and covert noise energy to heat.
(That is how all mufflers
work). It also helps the rest of the muffler live by
cooling it.

Air passing through that tube can warm the cabin. I would
make sure
it is .065 thick Inconel or .109 thick 321 SS and use a CO
monitor. The best kind is one that gives CO as a percentage of the
air coming through the system. This can give an early warning of
small leaks or cracks.
http://www.breathcotest.com/?gclid=CNy43YTbopgCFQHHGgodkRrmnQ

Paul Lamar

If anyone decides to use a heater core for cabin heat, there are a
couple of things to consider.Heater cores are generally
not built for a higher pressuresystem (15 - 30 psi).
They are designed for a 15 psi automotive application
which dumps the used coolant into a low pressure area.

Heater hoses and the hose bibs connecting to the heater
cores are generally the weak links of automotive systems.

That said, I personally would still prefer using coolant
rather than exhaust for cabin heat.

Joel

I know Ian Beadle (Renesis 6 port RV7) uses heated air from the back of
his water cooling radiator
and he has said that it works fine, but again he is in Perth Western
Australia where the temps never go below zero on the ground.

Steve Izett

Steve, next time you talk to Ian please tell him I would
like to see his new airplane in a couple of weeks. Last time I was out there
he took me for a flight in his first 13B rotary powered airplane :)


Paul Lamar