Engine configuration

Greetings!

My last post provoked a long and interesting series of threads so I am
emboldened to make another post.

This question concerns the configuration or layout of an engine. I have
noticed that air-cooled engines tend to have an opposed configuration
whereas liquid-cooled engines tend to have a V configuration. Both are
also available inline but I'll take a leap and say these are a minority
(I'm talking about current production engines not historical engines).
There are some liquid-cooled horizontally-opposed engines but I can't
think of any air-cooled "V" engines. Why is this? It suggests to me that
the advantages of the V configuration are specific to liquid cooling. Is
this really the case?

The Wikipedia article on "V Engine" is quite short but it includes this:

"Certain types of V engine have been built as inverted engines,
most commonly for aircraft. Advantages include better visibility
in a single-engined airplane, and lower centre of gravity."

OK, these are two pretty good advantages! There are no disadvantages
listed. So why isn't the Lycoming O-540 or the Continental O-520 an
inverted V?

Regards,

Michael

Michael Henry a écrit :

why isn't the Lycoming O-540 or the Continental O-520 an
inverted V?


They are derived from opposed engines, and the manufacturers thought
easier to retain the same cylinders and cylinder heads as their 4
cylinder counterparts.

There have been a number of aircooled inverted engines in the post WWII
period.

But it is hard to make statistics with Lyco/Cont being the sole small
engine manufacturers for decades.

Best regards,
--
Gilles
http://contrails.free.fr

"Michael Henry" wrote in message
...
Greetings!

My last post provoked a long and interesting series of threads so I am
emboldened to make another post.

This question concerns the configuration or layout of an engine. I have
noticed that air-cooled engines tend to have an opposed configuration
whereas liquid-cooled engines tend to have a V configuration. Both are
also available inline but I'll take a leap and say these are a minority
(I'm talking about current production engines not historical engines).
There are some liquid-cooled horizontally-opposed engines but I can't
think of any air-cooled "V" engines. Why is this? It suggests to me that
the advantages of the V configuration are specific to liquid cooling. Is
this really the case?

The Wikipedia article on "V Engine" is quite short but it includes this:

"Certain types of V engine have been built as inverted engines,
most commonly for aircraft. Advantages include better visibility
in a single-engined airplane, and lower centre of gravity."

OK, these are two pretty good advantages! There are no disadvantages
listed. So why isn't the Lycoming O-540 or the Continental O-520 an
inverted V?

Regards,

Michael

Lots of motorcycles out there that are air cooled v-twins. Granted they are
limited in horsepower for their displacement. ;^) (that ought to bring out the
Harley guys)

Paul

GTH wrote:
Michael Henry a écrit :

why isn't the Lycoming O-540 or the Continental O-520 an
inverted V?


They are derived from opposed engines, and the manufacturers thought
easier to retain the same cylinders and cylinder heads as their 4
cylinder counterparts.

OK so I just push my question back one generation: why is the O-360 not
an inverted V?

I'm asking more from a theoretical point of view. What is it that makes
the opposed configuration more attractive than the V configuration for
air-cooled engines? Likewise: what is it that makes the V configuration
more attractive than the opposed configuration for liquid-cooled engines?

There are new aircraft engine designs out the the Jabiru as an
air-cooled example and the Orenda as a liquid-cooled example. They
follow the same pattern that has become the norm.

There have been a number of aircooled inverted engines in the post WWII
period.

....and in the pre-WWII period! The deHavilland Gipsy Major being a
notable example.

"Michael Henry" wrote in message
...
Greetings!

My last post provoked a long and interesting series of threads so I am
emboldened to make another post.

This question concerns the configuration or layout of an engine. I have
noticed that air-cooled engines tend to have an opposed configuration
whereas liquid-cooled engines tend to have a V configuration. Both are
also available inline but I'll take a leap and say these are a minority
(I'm talking about current production engines not historical engines).
There are some liquid-cooled horizontally-opposed engines but I can't
think of any air-cooled "V" engines. Why is this? It suggests to me that
the advantages of the V configuration are specific to liquid cooling. Is
this really the case?

The Wikipedia article on "V Engine" is quite short but it includes this:

"Certain types of V engine have been built as inverted engines,
most commonly for aircraft. Advantages include better visibility
in a single-engined airplane, and lower centre of gravity."

OK, these are two pretty good advantages! There are no disadvantages
listed. So why isn't the Lycoming O-540 or the Continental O-520 an
inverted V?

Regards,

Michael

I can think of two inverted "V" air cooled aero engines that were produced
in quantity.
One is the German Argus As 10C 240HP used in the Me 108 and the Storch and
the other is the American Ranger V-770 inverted V12.
See: http://www.oldengine.org/members/die...ord/Ranger.htm
and http://en.wikipedia.org/wiki/Argus_As_10

On Dec 13, 4:53 am, Michael Henry wrote:
Greetings!

My last post provoked a long and interesting series of threads so I am
emboldened to make another post.

This question concerns the configuration or layout of an engine. I have
noticed that air-cooled engines tend to have an opposed configuration
whereas liquid-cooled engines tend to have a V configuration. Both are
also available inline but I'll take a leap and say these are a minority
(I'm talking about current production engines not historical engines).
There are some liquid-cooled horizontally-opposed engines but I can't
think of any air-cooled "V" engines. Why is this? It suggests to me that
the advantages of the V configuration are specific to liquid cooling. Is
this really the case?

The Wikipedia article on "V Engine" is quite short but it includes this:

"Certain types of V engine have been built as inverted engines,
most commonly for aircraft. Advantages include better visibility
in a single-engined airplane, and lower centre of gravity."

OK, these are two pretty good advantages! There are no disadvantages
listed. So why isn't the Lycoming O-540 or the Continental O-520 an
inverted V?

Regards,

Michael

VF-4 Wisconson industrial engine is an air cooled V configuration.

On Thu, 13 Dec 2007 21:53:23 +1000, Michael Henry
wrote:

The Wikipedia article on "V Engine" is quite short but it includes this:

"Certain types of V engine have been built as inverted engines,
most commonly for aircraft. Advantages include better visibility
in a single-engined airplane, and lower centre of gravity."

OK, these are two pretty good advantages! There are no disadvantages
listed. So why isn't the Lycoming O-540 or the Continental O-520 an
inverted V?

The practical difference in visibility between an inverted-V and a horizontally
opposed engine is minor, especially when the airplane they're used on has
tricycle gear vs. a taildragger. An inverted-V engine has a significant
visibility advantage over a radial, but they're no longer common in light
aircraft.

Same holds true for the lower CG: The inverted-V is much better than a radial,
but not that much better than the horizontally opposed engine. If you're
speaking of an air-cooled engine, much of the mass is in the crankcase, anyway,
irrespective of which way the cylinders poke.

And as you say: There are no disadvantages *listed* in a short Wikipedia
article. That does not mean there are no disadvantages. Access to the carb and
other elements that mount below the crankcase is probably more awkward; the
spark plugs may be more susceptible to oil fouling. For that matter, the
inverted-V may have the same problems with hydro lock as a radial...probably in
itself enough of a reason to favor horizontally opposed.

Ron Wanttaja

Michael Henry wrote:

what is it that makes the V configuration
more attractive than the opposed configuration for liquid-cooled engines?

Rotax 4 strokes are opposed, they also make inline 2 stroke air/water
cooled engines too...

"Bill Daniels" bildan@comcast-dot-net wrote:

I can think of two inverted "V" air cooled aero engines that were
produced in quantity.
One is the German Argus As 10C 240HP used in the Me 108 and the Storch
and the other is the American Ranger V-770 inverted V12.
See: http://www.oldengine.org/members/die...ord/Ranger.htm
and http://en.wikipedia.org/wiki/Argus_As_10

LOM's are still in production: http://www.moraviation.com

"Darrel Toepfer" wrote in message
. 18...
"Bill Daniels" bildan@comcast-dot-net wrote:

I can think of two inverted "V" air cooled aero engines that were
produced in quantity.
One is the German Argus As 10C 240HP used in the Me 108 and the Storch
and the other is the American Ranger V-770 inverted V12.
See: http://www.oldengine.org/members/die...ord/Ranger.htm
and http://en.wikipedia.org/wiki/Argus_As_10

LOM's are still in production: http://www.moraviation.com

I thought the original question was about inverted "V" engines. While the
LOM and Mikron engines are excellent products, they are inverted I-6 and I-4
engines, not a "V".

BTW, neither the LOM or the Ranger engines suffer from 'hydraulic lock'
which seems to be mostly related to P&W radials. I owned a Ranger inverted
in-line 6 which powered a PT - 19 and it never even smoked on start. I also
flew a Zlin with a LOM I-6 and it didn't give problems.

I think the inverted engines allow a nicer looking cowl and they do improve
the pilots visibility forward and down.

Bill Daniels