Engine question

Hallo,

i am wondering why American aircraftradialengines have no aerodynamical
spinners.Airplanes with inlineengines like P51;P40;P38 and so on have
aerodynamical optimized spinners.
And German radialengines had spinners like the FW190.Zero´s and other
Japanese aircraft had them.
What is the reason why the wellbuild American aircraft had just a little
hup on their propellers.
Thank You and greetings
Max

Max Richter wrote:

Hallo,

i am wondering why American aircraftradialengines have no aerodynamical
spinners.Airplanes with inlineengines like P51;P40;P38 and so on have
aerodynamical optimized spinners.
And German radialengines had spinners like the FW190.Zero´s and other
Japanese aircraft had them.
What is the reason why the wellbuild American aircraft had just a little
hup on their propellers.
Thank You and greetings
Max

I think that the reason is that because of the comparatively
large frontal area of most radial engines that a spinner is sort
of superfluous...IOW. the airstream is backed up well in front of
the prop hub therefore it 'makes it's own cone' in front of the
prop hub therefore a spinner on the prop hub would serve little
or no useful purpose...besides, you don't want the air to be
scooted outside the cylinders so what purpose could a spinner
provide? I'm open to other opinions...what say?...


(The small hub is necessary to contain the prop pitch change
mechanisms BTW...)

And on second thought the Beechcraft C-45 (Expeditor) does have
small spinners on their props...FWIW
--

-Gord.
(use gordon in email)

On Sat, 27 Aug 2005 21:02:11 GMT, Gord Beaman
wrote:

Max Richter wrote:

Hallo,

i am wondering why American aircraftradialengines have no aerodynamical
spinners.Airplanes with inlineengines like P51;P40;P38 and so on have
aerodynamical optimized spinners.
And German radialengines had spinners like the FW190.Zero´s and other
Japanese aircraft had them.
What is the reason why the wellbuild American aircraft had just a little
hup on their propellers.
Thank You and greetings
Max

I think that the reason is that because of the comparatively
large frontal area of most radial engines that a spinner is sort
of superfluous...IOW. the airstream is backed up well in front of
the prop hub therefore it 'makes it's own cone' in front of the
prop hub therefore a spinner on the prop hub would serve little
or no useful purpose...besides, you don't want the air to be
scooted outside the cylinders so what purpose could a spinner
provide? I'm open to other opinions...what say?...


(The small hub is necessary to contain the prop pitch change
mechanisms BTW...)

And on second thought the Beechcraft C-45 (Expeditor) does have
small spinners on their props...FWIW

They were probably not worth much. The Bugsmasher (a/k/a the
Smugbasher, a/k/a the SNB, a/k/a the C-45) was not exactly a high
speed aircraft. Some civilian versions of the Beech 18 were rather
quick (for their time) but still were 150-170 kt. aircraft (at the
outside).

The cost to fashion an aerodynamic "spinner" probably was not worth
the increase in performance.

The S2, with which I am very familiar, had just plain, old hubs. :-)

Bill Kambic

wrote:

On Sat, 27 Aug 2005 21:02:11 GMT, Gord Beaman
wrote:

Max Richter wrote:

Hallo,

i am wondering why American aircraftradialengines have no aerodynamical
spinners.Airplanes with inlineengines like P51;P40;P38 and so on have
aerodynamical optimized spinners.
And German radialengines had spinners like the FW190.Zero´s and other
Japanese aircraft had them.
What is the reason why the wellbuild American aircraft had just a little
hup on their propellers.
Thank You and greetings
Max

I think that the reason is that because of the comparatively
large frontal area of most radial engines that a spinner is sort
of superfluous...IOW. the airstream is backed up well in front of
the prop hub therefore it 'makes it's own cone' in front of the
prop hub therefore a spinner on the prop hub would serve little
or no useful purpose...besides, you don't want the air to be
scooted outside the cylinders so what purpose could a spinner
provide? I'm open to other opinions...what say?...


(The small hub is necessary to contain the prop pitch change
mechanisms BTW...)

And on second thought the Beechcraft C-45 (Expeditor) does have
small spinners on their props...FWIW

They were probably not worth much. The Bugsmasher (a/k/a the
Smugbasher, a/k/a the SNB, a/k/a the C-45) was not exactly a high
speed aircraft. Some civilian versions of the Beech 18 were rather
quick (for their time) but still were 150-170 kt. aircraft (at the
outside).

The cost to fashion an aerodynamic "spinner" probably was not worth
the increase in performance.


But wouldn't it be self defeating to do that?...if you made them
large enough to give you much of an increase in speed then
wouldn't they deprive the cylinders of enough cooling
airflow?...seems to me that they could have gained aerodynamic
efficiency by placing the prop further forward and then narrowing
the frontal air intake with cowlings. I suspect that they need
all the cooling that they now have (IOW, they're designed that
way)

The S2, with which I am very familiar, had just plain, old hubs. :-)

Bill Kambic

So did the Argus with which I'm very familiar too...

--

-Gord.
(use gordon in email)

"Gord Beaman" wrote in message
...

So did the Argus with which I'm very familiar too...

--

-Gord.

Gordon,

Was the Canadair Argus an American aircraft?

Oops.

Regards,

Tex

"Tex Houston" wrote:


"Gord Beaman" wrote in message
.. .

So did the Argus with which I'm very familiar too...

--

-Gord.

Gordon,

Was the Canadair Argus an American aircraft?

Oops.

Regards,

Tex

No Tex, it was Brit. (and I caught the little jab! Ü) Actually it
was a Bristol Britannia originally, they gave Canadair in
Montreal the license to build on the original plans and modify
them a bunch...musta been a humongous project...good article with
what was involved at:
http://www.geocities.com/cp107argus/CP107History.html

This is a good site for info on this (in it's time) the best ASW
aircraft in the world.

--

-Gord.
(use gordon in email)

"Tex Houston" wrote in message
...

"Gord Beaman" wrote in message
...

So did the Argus with which I'm very familiar too...

--

-Gord.

Gordon,

Was the Canadair Argus an American aircraft?


It had American engines

Oops.

Indeed

Keith

"Max Richter" wrote in message
...
Hallo,

i am wondering why American aircraftradialengines have no aerodynamical
spinners.Airplanes with inlineengines like P51;P40;P38 and so on have
aerodynamical optimized spinners.
And German radialengines had spinners like the FW190.Zero´s and other
Japanese aircraft had them.
What is the reason why the wellbuild American aircraft had just a little
hup on their propellers.
Thank You and greetings
Max


Probably because with all the rest of the engine exposed little was to be
gained but just looking at photographs try these (all verified by photos).
Some of these were built in quantity.

Boeing B-15/C-105
Boeing Model 337
Cessna 195
Convair B-36
Lockheed L-1049
Martin AM-1
Martin P4M
North American AJ-2
Ryan Spirit of St Louis
Vought F4U

Regards,

Tex Houston

Max Richter wrote:
Hallo,

i am wondering why American aircraftradialengines have no aerodynamical
spinners.Airplanes with inlineengines like P51;P40;P38 and so on have
aerodynamical optimized spinners.
And German radialengines had spinners like the FW190.Zero=B4s and other
Japanese aircraft had them.
What is the reason why the wellbuild American aircraft had just a little
hup on their propellers.
Thank You and greetings

Here's an example of one aircraft's evolution regarding spinners -- and
on-topic for the NG! g

XSB2C-1 & prod. -1's had a spinner w/ a 3-blade prop.
SB2C-3 w/ a 4-blade prop had no spinner.
SB2C-4 w/ a 4-blade prop had a spinner.
And finally the SB2C-5 had no spinner w/ it's 4-blade prop.

Just by looking over various pubs of the naval a/c which came out of
WWII (and those at the start) -- almost all had spinners at some point;
some only in the X-version. But the F2A (FWIW) had the spinner up
until the -3 version (which never saw front-line service.)

It would seem no version of the F4U had spinners.

The F8F had no spinner, yet at least one after-war modified Bearcat
racer had a very larger spinner.

Can't address what it means except to note that by the war's end, no
front-line naval a/c had spinners. The other comments all seem
logical, yet the SB2C evolution appears rather strange.

MW

"Max Richter" wrote in message
...
Hallo,

i am wondering why American aircraftradialengines have no aerodynamical
spinners.Airplanes with inlineengines like P51;P40;P38 and so on have
aerodynamical optimized spinners.
And German radialengines had spinners like the FW190.Zero´s and other
Japanese aircraft had them.
What is the reason why the wellbuild American aircraft had just a little
hup on their propellers.
Thank You and greetings
Max

Hummmmmm, a little before my time but from what I remember from talks with
my grandfather (he was a NAP) and my dad (also a Naval aviator) both whom
flew many different types of radial engine aircraft, I think that spinners
may have disrupted the air flow. Pre-WWII the intake designs being used were
classified. Developed they eventually gave almost a 10% performance
improvement over the designs in use in the rest of the world at the time.
The Jap "Zero" copied an earlier US intake design which added to its
performance, but this design still didn't perform as good as later (early
WWII) designs did. A 10% performance gained in aerodynamics and cooling, all
due to the shape of the cowling was nothing to pass up.

Many, many years have passed since those conversations with my grandfather
and my father. I just wish I had paid more attention to what they said about
their experiences. My grandfather flew for more than 25 years retiring in
1952 with 33 years in, and my father flew for 19 years before he passed in
1961.