Preheating engines: Airplane engines versus auto engines

On Wed, 19 Dec 2007 12:21:28 -0500, "Peter R."

Why is it that here in the Northeast US seemingly no one preheats their
automobile engine before start-up in very cold temperatures?

A) Automobiles have the advantage of 50+ years of research and innovation.
When did you last see a magneto ignition on a car? GA aircraft, however..

B) Ditto automobile oil. When I lived in the Twin Cities, Mobil 1 oil at
-25C was astonishing; you can spun over as if it was 35 degrees warmer.

C) Cars get used daily by most/many folks.

D) We're a nation of impatient, who GAF? people who'll sooner
buy a new car anyhow..


[ps: I did plug in my car when it got REALLY cold..]
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On Mon, 24 Dec 2007 04:47:22 +0000 (UTC), David Lesher
wrote:


On Wed, 19 Dec 2007 12:21:28 -0500, "Peter R."

Why is it that here in the Northeast US seemingly no one preheats their
automobile engine before start-up in very cold temperatures?

A) Automobiles have the advantage of 50+ years of research and innovation.
When did you last see a magneto ignition on a car? GA aircraft, however..

aircraft have the same period of innovation but the developments have
been for a different aim. longevity. once the designs reached their
light weight optimum many aspects have stayed fixed.
an engine running for long periods at the same rpm has what sort of
need for vacuum advance? ...for instance.
it does have a need to be able to continue to run in spite of
electrical failure and a magneto and gravity feed do that for many
designs quite adequately. simplicity removes failure points due to
complexity. failures can kill you, simplicity keeps you alive.

aircraft have a higher risk of being struck by lightning. how much of
the high tech auto technology can survive a lightning strike?

I must admit that the dead hand of certification needs to be phased
out if there is any prospect of innovation again.
the current cosworth formula1 engines deliver 950hp at 20,000rpm from
an engine package smaller in capacity than an O-200.
I wouldnt mind a little bit more bleed through of the technology into
aviation.



B) Ditto automobile oil. When I lived in the Twin Cities, Mobil 1 oil at
-25C was astonishing; you can spun over as if it was 35 degrees warmer.

C) Cars get used daily by most/many folks.

D) We're a nation of impatient, who GAF? people who'll sooner
buy a new car anyhow..

ahhh but that is the actual reason for the technical inovation behind
the automobile. it self perpetuates the sale of new cars.
functionally a T model ford would get you around as well as any modern
car. the expectations driven by technology wouldnt allow you to be
seen dead in one so you go out and buy a new high tech car capable of
200mph and a standing quarter in 5 seconds ...so that you can drive it
in peak hour stop start traffic all the while dreaming of a circuit at
brands hatch.
cunning buggers arent they :-)

aircraft have the same period of innovation but the developments have
been for a different aim. longevity. once the designs reached their
light weight optimum many aspects have stayed fixed.
an engine running for long periods at the same rpm has what sort of
need for vacuum advance? ...for instance.
it does have a need to be able to continue to run in spite of
electrical failure and a magneto and gravity feed do that for many
designs quite adequately. simplicity removes failure points due to
complexity. failures can kill you, simplicity keeps you alive.



The thing that inhibits aircraft engine development appears to be simple
economics. With the HUGE certification and liability hurdles, there
simply are not enough potential sales to offset this economic mountain.
Auto engines can afford to fail in use because the consequences are
generally much less severe (you coast to a stop on the side of the
road). If the proposed auto innovation passes its early tests, the
market potential is generally large enough to make financial sense to go
ahead and put the thing in production.

The litigation blood suckers just about DARE anyone to attempt to
introduce any changes to the airplane market. The idiotic public puts up
with this nonsense and cheers on the suing family as they battle the
"big, bad corporation" who harmed their poor, defenseless family with
their "defective" product.

Airplane owners have a split personality as far as I can tell by reading
these forums. We cry "foul" when some idiot jury awards millions of
dollars in damages for an airplane mishap. But pilots are the first in
line to blame anyone in sight when it happens to them.

Curious lot.

Be Safe,
Mike

Stealth Pilot writes:

A) Automobiles have the advantage of 50+ years of research and innovation.
When did you last see a magneto ignition on a car? GA aircraft, however..

aircraft have the same period of innovation but the developments have
been for a different aim. longevity. once the designs reached their
light weight optimum many aspects have stayed fixed.

I respectfully disagree. There are many things we've learned from which
GA aircraft could benefit: automotive, electronic, metallurgical, human
factors.

That they don't is likely due to a "coffin corner" of low volumes, and
high overhead {including but not limited to regulatory burden..}.

Do I think aircraft engines could benefit from closed loop fuel
systems [ie fuel injection/FADEC]? Yep. Do I think such can survive
lightning? Yep. The Big Boys and the military aircraft do now; I recall
that thunderstorm research fighter at NASA-LaRC with the dozens of
thunderbolts stencils. Ditto TV/FM transmitters, who unlike the aircraft,
ARE a direct sink for the lightning. It takes some design but nothing
earthshaking.

But even small stuff, such as integral voltage regulators [inside
alternators] does not seem to come to pass.

an engine running for long periods at the same rpm has what sort of
need for vacuum advance? ...for instance.

Suppose a computerized fuel injection system offered oh, say 7% better
fuel consumption and 20% better TBO; would that be worth it? Look at the
MPG and engine life of a 1950's car and one from the last 5 years.

D) We're a nation of impatient, who GAF? people who'll sooner
buy a new car anyhow..

ahhh but that is the actual reason for the technical inovation behind
the automobile. it self perpetuates the sale of new cars.

Perhaps, but the outcome is better cars. Until the Japanese invasion,
Detroit built crap, at multiple levels: engineering, manufacturing,
QC. The dope-slap they got took years to wake them up, but it and
regulatory burdens [1] have given the customer a vehicle that's far far
better than what [s]he could buy 40 years ago. I wish the GA industry
could say the same.


1: The MPG/smog ones forced them to give up on carbs. How could anyone
ever have improved on a Rochester Quadrajet for example -- why, it's a
marval of simplicity exceeded only by the 6.02E23 parts found in a
Model 28 Teletype, right?]
--
A host is a host from coast to
& no one will talk to a host that's close........[v].(301) 56-LINUX
Unless the host (that isn't close).........................pob 1433
is busy, hung or dead....................................20915-1433

"nrp" wrote in message
...
...
A lot of this moisture accumulation problem would go away if aircraft
engines had a positive crankcase ventilation (PCV) system like car
engines now do, but they don't for whatever reason. I suspect part of
the reason car engines now last so much longer is due to the PCV
system.

Talking to one of the "old guys" at work some years ago this came up - his
claim was that when PCV was first required, they were worried about
re-cycling all the "gunk" and damaging the engines - but testing (and
eventually field experience) showed that keeping the crankcase ventilated
resulted in a significant boost in engine durability. He referred to PCV as
one of the best things to come along...

Conventional auto style PCV won't work well on an aircraft engine due to the
lack of vacuum in the manifold to generate the air flow.

--
Geoff
The Sea Hawk at Wow Way d0t Com
remove spaces and make the obvious substitutions to reply by mail
When immigration is outlawed, only outlaws will immigrate.

"Stealth Pilot" wrote in message
...
...
now to be serious...
squeezing past the rings probably contributes a millionth of one
poofteenth of a percent to the problem.

Stick your thumb on the crankcase breather and have someone open the
throttle - you will be surprised at the ammount of flow.

--
Geoff
The Sea Hawk at Wow Way d0t Com
remove spaces and make the obvious substitutions to reply by mail
When immigration is outlawed, only outlaws will immigrate.

On Fri, 21 Dec 2007 08:18:12 -0800 (PST),
wrote:

On Dec 21, 4:45 am, Stealth Pilot
wrote:

squeezing past the rings probably contributes a millionth of one
poofteenth of a percent to the problem.
when the crankcase cools there is moist external air sucked into the
cavity of the case through the crankcase breather. the moisture
condenses onto the cold internal surfaces of the engine.
can you please factor that into the alchemy above? it probably does
the damage occurring between the poofteenth of your scenario and the
100%.

Nope. We have taken rocker covers off engines immediately
after a runup of a brand-new engine and found copious amounts of water

A runup doesn't do squat about removing moisture or acid. It takes a
10 to 15 minute flight of take off and cruise power. I've never seen
moisture after that, but I sure have after even a prolonged ground
run. Besides, unless it's tied down I can't even hit cruise power in
the runup without the tires skidding let alone full power. 24 X 24
and it'll start to acellerate which is kinda hard on the tires.

Roger (K8RI)
in them. The blowby of any cold engine is significant. If we briefly
run up an engine that has sat all night in a heated hangar and in our
very dry winter climate, we will find water on the dipstick every
time, with the engine at any point in its life. And the dipstick was
dry beforehand.
We operate on the western Canadian prairies where the air is
drier that where I grew up in south-central BC, which is the northern
tip of the Sonora Desert. We get little rain and snow here. Temps
reach -40C, more typically -20C, no fog and clear skies most of the
winter. It's REALLY dry, and any air sucked into these engines after
shutdown doesn't have enough moisture to make a couple of tears.

Dan

On Dec 25, 9:13 pm, "Roger (K8RI)" wrote:

Nope. We have taken rocker covers off engines immediately
after a runup of a brand-new engine and found copious amounts of water

A runup doesn't do squat about removing moisture or acid. It takes a
10 to 15 minute flight of take off and cruise power. I've never seen
moisture after that, but I sure have after even a prolonged ground
run. Besides, unless it's tied down I can't even hit cruise power in
the runup without the tires skidding let alone full power. 24 X 24
and it'll start to acellerate which is kinda hard on the tires.

My point was that there was lots of moisture in the case after a
runup, and that it would take considerable hard flying to get it out.
We had to redo jugs on our O-235 in one of the Citabrias at mid-
time. Those engines tend to run cool (I have no idea at all why
American Champion installs an oil cooler; its finned area is half
blocked off as installed and they incude a cover to block the rest off
in cooler weather) and the resulting condensation corrodes the
cylinder walls. The worst damage was on the front of the front
cylinders, the first area to cool after a flight, and that moisture
causes galvanic corrosion (aluminum piston against steel wall) and
pitting there. Then the rings wear it at a greater rate, a ridge forms
at the bottom of the ring travel, and that sharp ridge starts shaving
aluminum bits off the piston pin plugs. Aluminum slivers in the filter
are the first sign of the trouble.

Dan

On Dec 25, 8:13 pm, "Roger (K8RI)" wrote:




A runup doesn't do squat about removing moisture or acid. It takes a
10 to 15 minute flight of take off and cruise power. I've never seen
moisture after that, but I sure have after even a prolonged ground
run.

10 to 15 minutes at cruise prower is a reasonable claim. To say it
takes at least one hours to heat up the engine enough to boil off
water is OWT (which I often hear about). If one thinks a 30 minute
cruise flight is too short to get rid of the water, does he reduce
power to land? The engine cools off as the plane descends and water
starts to accumulate in the oil according to this theory.

On Dec 24, 2:42 am, Stealth Pilot
I must admit that the dead hand of certification needs to be phased
out if there is any prospect of innovation again.
the current cosworth formula1 engines deliver 950hp at 20,000rpm from
an engine package smaller in capacity than an O-200.

I doubt such a formula 1 engine would have better power to weight
ratio if you add the weight of the reduction gear to get the prop tip
speed below supersonic. I also doubt it can match the BSFC of a
O-200.

People often claim the auto engines are so much better. I'd like to
see an automobile gasoline engine that has 1. better BSFC than an
IO-550 at its 75% rated power and 2. better power to weight ratio
including the weight of the reduction gear to drive a propeller.

http://www.prime-mover.org/Engines/G.../article2.html has a lot
of good info.