Cold Starts

Then there is the Alaska way. Drain the oil and take it inside. Then
during breakfast, heat oil to 200 degrees. Pour hot oil back into
engine. Engine nice and warm. Chase off Grizzlies. Start airplane.

Rich wrote in message ...
No No!
Ground running is NOT good for an engine. Uneven cooling, you know!

Take it up for a 1 hour FLIGHT each four hours!

That's the PROPER way to keep it warm.

Rich

Doug wrote:

Well,,,desperate men do desperate things.

Stay at a motel near the airport and go out and start your plane and
run it for 1/2 hour every 4 hours. Bring the walkman.

I suspect your battery / cables are marginal... I have the Concorde RG
battery and the original piper aluminum cables, in a twin which means looong
cables... My non heated engines spin just fine regardless of temperature...

I do keep the cable connections polished and greased with Dow silicone...
But the real eye opener was the Concorde RG battery... day and night
difference compared to a standard battery...
denny

"Jay Honeck" wrote in message
news:CivYb.339528$xy6.1678994@attbi_s02...
well, I've done the no-preheat thing on a 30 degree day and the prop
didn't spin all that fast (barely started). With a preheat on a
20 degree day the prop spins a lot faster.

Doug wrote:
Then there is the Alaska way. Drain the oil and take it inside. Then
during breakfast, heat oil to 200 degrees. Pour hot oil back into
engine. Engine nice and warm. Chase off Grizzlies. Start airplane.

Your engine isn't warm, the oil is. You are much better off heating the
oil while it is still in the plane.

Dave Stadt wrote:
:The
: cylinders themselves have choke (they're slightly smaller bore at the
: top), with the
: thought being they'll expand to be straight when they heat up during
: normal operation.
: Those two things are the primary reasons.... lack of oil and scuffing of
: cylinders.

: Doesn't play. The pistons are aluminium and the bores are steel. In cold
: weather the aluminium pistons shrink more than the steel cylinders and
: clearance actually increases. The rings are steel and follow the cylinders.

True... except the piston is warmed by the first few seconds/minutes of
combustion much quicker than the steel cylinders. It's not the starting so much as
the dissimilar warmup. If the cylinders are pre-warmed, the temperature differential
to be transitioned through is lower. Granted it's engine preheater propaganda,
I believe there's some truth to the research in http://www.tanair.com/article6.html.

If you get high-time from your engine without preheat, then good for you.
Nobody said that cold-starts are the only cause of engine wear, and I'm sure that for
particular engines it's worse than others. As always, YMMV.

-Cory

--
************************************************** ***********************
* The prime directive of Linux: *
* - learn what you don't know, *
* - teach what you do. *
* (Just my 20 USm$) *
************************************************** ***********************

Newps wrote in message news:9KKYb.351852$na.520642@attbi_s04...
Doug wrote:
Then there is the Alaska way. Drain the oil and take it inside. Then
during breakfast, heat oil to 200 degrees. Pour hot oil back into
engine. Engine nice and warm. Chase off Grizzlies. Start airplane.

Your engine isn't warm, the oil is. You are much better off heating the
oil while it is still in the plane.

True, but all it takes is a pan and a stove. Besides, they don't have
electricity in Alaska ;-)

Newps wrote in message news:9KKYb.351852$na.520642@attbi_s04...
Doug wrote:
Then there is the Alaska way. Drain the oil and take it inside. Then
during breakfast, heat oil to 200 degrees. Pour hot oil back into
engine. Engine nice and warm. Chase off Grizzlies. Start airplane.

Your engine isn't warm, the oil is. You are much better off heating the
oil while it is still in the plane.

The reason for the Alaskan habit is that when temps go low enough, a
chunk of frozen oil can develop in the crankcase. Even after
preheating the engine to what seems to be a suitable temp, you can
have a frozen chunk of oil surrounded by slightly warmer liquid oil.
I recall reading at least 1 accident report that was blamed on frozen
oil blocking the pickup. The engine had been preheated (but obviously
not enough).

John Galban=====N4BQ (PA28-180)

wrote in message
...
Dave Stadt wrote:
:The
: cylinders themselves have choke (they're slightly smaller bore at the
: top), with the
: thought being they'll expand to be straight when they heat up during
: normal operation.
: Those two things are the primary reasons.... lack of oil and scuffing
of
: cylinders.

: Doesn't play. The pistons are aluminium and the bores are steel. In
cold
: weather the aluminium pistons shrink more than the steel cylinders and
: clearance actually increases. The rings are steel and follow the
cylinders.

True... except the piston is warmed by the first few seconds/minutes of
combustion much quicker than the steel cylinders. It's not the starting
so much as
the dissimilar warmup. If the cylinders are pre-warmed, the temperature
differential
to be transitioned through is lower.

Percentage wise the difference is minimal.

Granted it's engine preheater propaganda,
I believe there's some truth to the research in
http://www.tanair.com/article6.html.

If you get high-time from your engine without preheat, then good for you.
Nobody said that cold-starts are the only cause of engine wear, and I'm
sure that for
particular engines it's worse than others. As always, YMMV.

I do preheat but to be honest I don't know why. Nothing in this discussion
has convinced me that anybody knows why or what harm, if any, is caused by
not preheating. Only thing I know for sure is preheating makes it much
easier to start the engine.


-Cory

--
************************************************** ***********************
* The prime directive of Linux: *
* - learn what you don't know, *
* - teach what you do. *
* (Just my 20 USm$) *
************************************************** ***********************

In article , "Dennis O'Connor"
wrote:

I suspect your battery / cables are marginal... I have the Concorde RG
battery and the original piper aluminum cables, in a twin which means
looong
cables... My non heated engines spin just fine regardless of
temperature...

I have copper cables and it was a new battery. Frankly, I'm not
sure how marginal battery and cables would be improved by a preheat.


I do keep the cable connections polished and greased with Dow silicone...
But the real eye opener was the Concorde RG battery... day and night
difference compared to a standard battery...
denny

A lightweight starter is amazing (when warm) - no more "bumping"
the starter on my cherokee 140, but the prop still spins pretty
slow without the preheat.




"Jay Honeck" wrote in message
news:CivYb.339528$xy6.1678994@attbi_s02...
well, I've done the no-preheat thing on a 30 degree day and the prop
didn't spin all that fast (barely started). With a preheat on a
20 degree day the prop spins a lot faster.



--
Bob Noel

Bob Noel wrote:

I have copper cables and it was a new battery. Frankly, I'm not
sure how marginal battery and cables would be improved by a preheat.

Depends on how you preheat and the location of the battery. Many people stick
the output of the preheater into the front air intakes. That heats pretty much
only the cylinders. Since the valves are the weak point in aircraft engines,
that takes care of the situation pretty well.

I put the heat into the air discharge area. That not only heats the cylinders,
but the oil sump and accessory area warm up too. My battery is mounted on the
firewall, so it warms up a bit.

Warm batteries work better than cold ones - that's why arctic photographers
keep spares next to their skin. If your battery is in the tail, however, this
isn't going to help you any.

George Patterson
A diplomat is a person who can tell you to go to hell in such a way that
you look forward to the trip.

Dave Stadt wrote:

I do preheat but to be honest I don't know why.

Continental will tell you that failure to preheat one of their engines when the
temperature is below 20 degrees F may result in a snapped valve stem. Good enough?

George Patterson
A diplomat is a person who can tell you to go to hell in such a way that
you look forward to the trip.