Aaron Coolidge wrote:
: Hi Cory, I think that if you have airflow the head is an efficient heat
: dissipator. If you have no airflow, the metal components of the cylinder
: will eventually get to thermal equilibrium regardless of the position of
: the heating elements.
Correct, but remember this. There *are* heat leaks somewhere or else it would
get hotter and hotter. That means that there's heat flow. AUIU, once the convective
air is blocked, the prop/cranks is the biggest heat sink of all... sucks heat right
out of the case. There *will* be a thermal gradient under the hood... hottest places
at the elements, and coldest at the heat sinks.

I have a reiff system; my plane is kept outside in
: Southeastern MA; I do not have a cowling cover (but the fiberglass
: cowling is a good insulator and I use cowl plugs). I find a 30 deg F rise
: at the cyl head on the coldest days that we experience. I measured 30degF
: at the #1 cyl head with my trusty Omega handheld thermocouple with 0 degF
: ambient. I am satisfied.
Agreed... I generally run the same setup... no cover, but cowl plugs. I
haven't put a thermocouple on them, but at 20F the heads are quite warm to the
touch... I'd say 40-50. Sounds like the same 30 degree rise. With better insulation,
things would be even better.

: I got the Reiff because I can't stand tanis' web site! I was impressed with
: Reiff's after-sale service, as well. When I messed up gluing the heater
: to the oil sump they sent me a new batch of glue. The glue is just metal-
: filled epoxy (think J-B Weld), but I wanted to use their "special" stuff
: anyway.
: --
: Aaron C.

I got mine used, so it was cheaper and didn't have support no matter what.
I'm not saying Reiff sucks. It's much better than leaving one cylinder without heat
IMO. I'm just saying that aside from that issue with the Tannis, Reiff bands will
probably perform "up to and possibly including" tannis performance...

-Cory
--

************************************************** ***********************
* Cory Papenfuss *
* Electrical Engineering candidate Ph.D. graduate student *
* Virginia Polytechnic Institute and State University *
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