Oh those CERTIFIED plane engines !!!!!!!!!!!!!!!!!

If I may be forgiven (or not) for reading about the Corvair crank
failures with rectal vision, they should not have surprised anyone.

If you would read the site again, I think you will find that the breaking
problem is limited to higher speed airplanes, not stuff like aircampers,
right?

It is highly unlikely that any auto manufacturer is going to put
a crankshaft that is a whole lot stronger than needed into a
standard engine, don't you think?

Some manufacturers, at certain times in their lifespan, are less
comfortable
with cutting design strength margins too closely. GM is more likely to
build hell for stout, than are many of the imports, IMHO.

And even more than the "aircraft" manufacturers, where weight IS the
enemy, and where change for improvement's sake is very much frowned
upon. If you change or improve something, you are admitting something
was less than perfect, and leaving yourself vulnerable to that
"unwashed horde" known as the "legal proffesion".

I also love to pick. However, let's also remember that improvements and
vendor changes also have a way of restarting the entire field experience
process--as has been discussed earlier in this thread, and also in AvFlash,
with regard to Lycoming...

Morgans wrote:

Some manufacturers, at certain times in their lifespan, are less comfortable
with cutting design strength margins too closely. GM is more likely to
build hell for stout, than are many of the imports, IMHO.

There's a little difference. When the engine breaks in your car, you
can pull off the road and call a tow truck.

"Orval Fairbairn" wrote

I have also seen a few successes, too. One was the late George Morse's
Olds V-6 in his Skybolt and later in the Prowler. He found that you need
an AN water pump instead of the automotive one and that you also need a
coolant pressure indicator, in addition to temperature.

What do you mean by an AN water pump?

One of the common things people say about auto conversions, is that they are
not designed to run at the high power outputs that are needed for aircraft.

It seems, however, that most of the problems are in the stuff that is bolted
to the engine. PSRU's fail, water pumps go out, belts fly around, fuel
delivery is not up to the job, cooling is not good enough, whatever. The
engines are rarely the problem, though.

Good design and doing what other successful converters have done, looks to
be the key.
--
Jim in NC

"Cal Vanize" wrote in message
...
Morgans wrote:

Some manufacturers, at certain times in their lifespan, are less
comfortable
with cutting design strength margins too closely. GM is more likely to
build hell for stout, than are many of the imports, IMHO.

There's a little difference. When the engine breaks in your car, you
can pull off the road and call a tow truck.


True ... but ...
Engines in cars rarely break. Possibly as rarely as _real_ airplane
engines. However, I have seen a broker crank in a 40 HP Volkswagen, which
my brother and I bought. We rebuilt another engine and installed it with no
further problems. I also used to know a truck mechanic who saw the
occasional broken crank; usually, or perhaps always, after seeing a failed
torsional harmonic dampened--and trying without success to convince the
owner to replace it.

I leave it to the reader to make the connection; as I have beaten that dead
horse far too much, and not only on this NG.

"Morgans" wrote in message
...

"Cal Vanize" wrote

There's a little difference. When the engine breaks in your car, you
can pull off the road and call a tow truck.

Humm, I don't know a single person that has had a broken crank, in his
car.
Can you say the same about your friend's airplanes?

When an auto engined airplane powerplant fails, it is almost always not
the
engine, but what has been bolted to it. It seems like airplane engines
are
always blowing jugs off, sticking valves, and breaking rods and cranks.
They are not confidence inspiring, to me.

True, auto engines in airplanes have a way to go, but if someone were to
put
the effort into making a standard package, and perfecting it, they would
really go far. Some are getting really close.
--
Jim in NC

You've summed it up quite well, Jim.

Peter in FL

"Cal Vanize" wrote

There's a little difference. When the engine breaks in your car, you
can pull off the road and call a tow truck.

Humm, I don't know a single person that has had a broken crank, in his car.
Can you say the same about your friend's airplanes?

When an auto engined airplane powerplant fails, it is almost always not the
engine, but what has been bolted to it. It seems like airplane engines are
always blowing jugs off, sticking valves, and breaking rods and cranks.
They are not confidence inspiring, to me.

True, auto engines in airplanes have a way to go, but if someone were to put
the effort into making a standard package, and perfecting it, they would
really go far. Some are getting really close.
--
Jim in NC

In article ,
"Morgans" wrote:

"Orval Fairbairn" wrote

I have also seen a few successes, too. One was the late George Morse's
Olds V-6 in his Skybolt and later in the Prowler. He found that you need
an AN water pump instead of the automotive one and that you also need a
coolant pressure indicator, in addition to temperature.

What do you mean by an AN water pump?

IIRC, George meant to use a water pump such as used on Merlins or
Allisons. he found the automotive pumps to be lacking.



One of the common things people say about auto conversions, is that they are
not designed to run at the high power outputs that are needed for aircraft.

It seems, however, that most of the problems are in the stuff that is bolted
to the engine. PSRU's fail, water pumps go out, belts fly around, fuel
delivery is not up to the job, cooling is not good enough, whatever. The
engines are rarely the problem, though.

True! If you isolate the engine from unintended stresses, it will work a
lot better, but those same stresses manifest themselves in other places,
unless you are really sharp anticipating them.


Good design and doing what other successful converters have done, looks to
be the key.

True -- that is *ALWAYS* the case! Add in "good practices" also.

In article ,
"Morgans" wrote:

"Cal Vanize" wrote

There's a little difference. When the engine breaks in your car, you
can pull off the road and call a tow truck.

Humm, I don't know a single person that has had a broken crank, in his car.
Can you say the same about your friend's airplanes?

I had a broken crank in a 356C Porsche (rebuilt engine/chromed crank). I
think the real problem was that the shop that chromed the crank didn't
bake it properly to eliminate hydrogen embrittlement.


When an auto engined airplane powerplant fails, it is almost always not the
engine, but what has been bolted to it. It seems like airplane engines are
always blowing jugs off, sticking valves, and breaking rods and cranks.
They are not confidence inspiring, to me.

True, auto engines in airplanes have a way to go, but if someone were to put
the effort into making a standard package, and perfecting it, they would
really go far. Some are getting really close.

I had an E-225 swallow a valve in a Bonanza once -- shook like hell at
anything over 1500 RPM!

"Orval Fairbairn" wrote

IIRC, George meant to use a water pump such as used on Merlins or
Allisons. he found the automotive pumps to be lacking.

I was unaware that a water pump for a Merlin or an Allison would fit on an
American V-8! g

Really, though, I don't understand what he would be referring to. Is it
something like what is commonly used on racing (NASCAR) engines? What
companies make something compatible, in that design?

I had always thought that special design was needed to get the accessories
running at a slower than stock RPM, either by using a smaller than normal
drive pulley, or larger than normal accessory pulley. I would think that
better bearings would be good things for a water pump.
--
Jim in NC

Morgans wrote:
"Cal Vanize" wrote

There's a little difference. When the engine breaks in your car, you
can pull off the road and call a tow truck.


Humm, I don't know a single person that has had a broken crank, in his car.
Can you say the same about your friend's airplanes?

When an auto engined airplane powerplant fails, it is almost always not the
engine, but what has been bolted to it. It seems like airplane engines are
always blowing jugs off, sticking valves, and breaking rods and cranks.
They are not confidence inspiring, to me.

True, auto engines in airplanes have a way to go, but if someone were to put
the effort into making a standard package, and perfecting it, they would
really go far. Some are getting really close.

Many people ARE working on it, of course.

A friend in Hondo has been for several years.
He runs the local crop dusting service and flies Snows, AgTrucks, and a couple
of small Cessnas. There are a few Garret powered planes as well - sweet, but
pricey to purchase, and operate.

One season, he replaced 13 cylinders on ONE of his 1835s.
THAT'S a chunk of change, folks!

His idea is to use a large block V8 to power his fleet, and has had one up
and flying. That one used a belt driven PSRU, and actually flew a few hours
before it was lost in a hangar fire. Reliability was never fully explored,
but there were some doubts as to how long it would have lasted in service.

The next step was to have a gearbox designed - by a well known name in this
field. Several years, a lot of drawings, and planning - and money? before
this one was dropped.

The current plan is for a chain drive. Another well known name in the field,
but this guy says he can have it up and running in 60 days.

The FAA agrees that the duster fleet needs modernized power and is very
interested in the results. No dusters - no food - and an epidemic of RATS!

My own feeling is that the crop dusting fleet NEEDS this kind of power and
reduced operating costs! And the aircraft size makes it quite adaptable to
such engines. As opposed to very small, very light, very experimental
airframes.

Given enough time and money....

Richard