Hard Starting Cold Continental Engines

"Kobra" wrote in message
...

throttle open 1/4 inch
mixture full rich
electric fuel pump/prime on
wait a few seconds (2 at the most)
crank


I agree...you are NOT priming enough. In the cold weather you can prime
twice as long as in warm weather or even longer. Also, don't forget that
the plugs can ice over (or so I am told) and this will cause the plug not
to spark. Old wife's tale? Possibly but it makes sense to me.

Kobra

Yea, what he said.

If you (the original poster) were as old as me, and had grown up pulling on
a manual choke every time you started the car, you would realize that cold
engines need a lot more fuel to get started than warm engines. All that
automatic, electonic stuff might be nice for emssions and reliability (and
keeping me employed) but they do insulate the average person from the
mechanics of "how an engine works"...

And, no, icing plugs is not an old wives tale. Usually happens when the
engine fires only once or twice but doesn't start.

--
Capt. Geoffrey Thorpe
The Sea Hawk At WowWay D0t Com

wrote in message
You just need to figure out how much fuel your particular pair of
engines need to start with varying OAT's

TC

TC makes a very important point that is often overlooked when training
pilots. I usually start by asking a student what they think happens with
the density altitude is when it's cold, then I ask them what that does to
their fuel/air mixture. Next question is, if you've got more air, don't you
need more fuel? It's amazing how many show surprise. Same theory, opposite
actions for hot temps and hot starts.

Jim

M.E. Borner wrote:

My un-preheated cold weather/cold engine starting technique is very
similar to my warm weather/cold engine technique

You might want to consider investing a (relatively) small amount of
money in a Tanis heating system. The cost of overhauling those two
engines, including removal, shipping, and reinstallation, would get you
a good way towards buying a house in some of the poorer states, so a
couple of thousand (including labour) for a heating system and
insulated covers would be a wise investment.

If you don't have access to electricity, is there a Herman Nelson or
similar force-air preheater somewhere on your field? If not, perhaps
there are small, portable, propane-powered forced-air heaters you could
buy and bring out with you (I haven't investigated this, since I keep
my plane at a major airport with lots of services).

When you're visiting a remote airport, you can always cover the engines
after a flight -- they should stay warm for quite a few hours under an
insulated cover.

I have to admit that I've cold-started the O-320 on my Warrior down to
-15 degC (with a *lot* of priming), but I'm not proud of it. Now, with
a newly-overhauled engine, I've moved to a spot where I can leave my
Tanis plugging in all winter to protect the investment.


Best of luck,


David

I won't start my 172M without preheat unless it is above 40 degF or has
been running recently - and that's with the multivis Aeroshell.

Lycomings are unusually sensitive to cold start cam damage. My
thinking is that even a single episode can create internal mayhem.

Perhaps my description was not clear enough. My engines do have Tanis
preheaters on them. When I preheat the engine everything is fine, it
starts like a mid-summer day. The problem is when it is cold and I am
unable to preheat due to lack of accessibility to electricity.

M.E. Borner wrote:

Perhaps my description was not clear enough. My engines do have Tanis
preheaters on them. When I preheat the engine everything is fine, it
starts like a mid-summer day. The problem is when it is cold and I am
unable to preheat due to lack of accessibility to electricity.

It might be worth trying to find some other way to preheat when you
cannot plug in (get the plane pulled into a heated hangar, or borrow a
forced-air heater). Your engines might be trying to send you a
message.


All the best,


David

Portable generator?

"M.E. Borner" wrote in message
ups.com...
Perhaps my description was not clear enough. My engines do have Tanis
preheaters on them. When I preheat the engine everything is fine, it
starts like a mid-summer day. The problem is when it is cold and I am
unable to preheat due to lack of accessibility to electricity.