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ŽiŠardo[_2_]
March 19th 13, 05:15 PM
--
Moving Things in Still Pictures!

Dave Kearton[_3_]
March 19th 13, 07:26 PM
"ŽiŠardo" > wrote in message
...
>
> --
> Moving Things in Still Pictures!
>




Well, that's an interesting engine arrangement. (to put it mildly)


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Cheers

Dave Kearton

ŽiŠardo[_2_]
March 19th 13, 08:01 PM
On 19/03/2013 19:26, Dave Kearton wrote:
> "ŽiŠardo" > wrote in message
> ...
>>
>> --
>> Moving Things in Still Pictures!
>>
>
>
>
>
> Well, that's an interesting engine arrangement. (to put it mildly)
>
>

Hi Dave,

Yes, as explained to Indrek:

"Macchi-Castoldi MC-72 Fiat AS6 engine; dual V-12, 3100 total HP,
each engine drives one very course, fixed-pitch prop 440.729 mph in
1934. Class record still stands. Why contra-prop? Supermarine S6B w/
2650 HP on single prop overloaded one float by 32% on takeoff due to
torque."

Regards,

RiŠardo

--
Moving Things in Still Pictures!

Dave Kearton[_3_]
March 19th 13, 10:02 PM
"ŽiŠardo" > wrote in message
...
> On 19/03/2013 19:26, Dave Kearton wrote:

> Hi Dave,
>
> Yes, as explained to Indrek:
>
> "Macchi-Castoldi MC-72 Fiat AS6 engine; dual V-12, 3100 total HP,
> each engine drives one very course, fixed-pitch prop 440.729 mph in 1934.
> Class record still stands. Why contra-prop? Supermarine S6B w/ 2650 HP on
> single prop overloaded one float by 32% on takeoff due to torque."
>
> Regards,
>
> RiŠardo
>



What fascinated me is the engineering work required to get the job done.
Not only are there two unique engines inline, but the crankshafts can't be
simply bolted together.

I've been thinking about it for a while now and I can't think of a simple
way to do it reliably.


All that effort and expense for a one-off design. Absolutely outstanding
that they got it to work at all, much less in the '30s.




--



Cheers

Dave Kearton

ŽiŠardo[_2_]
March 20th 13, 09:24 AM
On 19/03/2013 22:02, Dave Kearton wrote:
> "ŽiŠardo" > wrote in message
> ...
>> On 19/03/2013 19:26, Dave Kearton wrote:
>
>> Hi Dave,
>>
>> Yes, as explained to Indrek:
>>
>> "Macchi-Castoldi MC-72 Fiat AS6 engine; dual V-12, 3100 total HP,
>> each engine drives one very course, fixed-pitch prop 440.729 mph in
>> 1934. Class record still stands. Why contra-prop? Supermarine S6B w/
>> 2650 HP on single prop overloaded one float by 32% on takeoff due to
>> torque."
>>
>> Regards,
>>
>> RiŠardo
>>
>
>
>
> What fascinated me is the engineering work required to get the job done.
> Not only are there two unique engines inline, but the crankshafts can't
> be simply bolted together.
>
> I've been thinking about it for a while now and I can't think of a
> simple way to do it reliably.
>
>
> All that effort and expense for a one-off design. Absolutely
> outstanding that they got it to work at all, much less in the '30s.
>
>
>
>

It shows the prestige attached to the Schneider Trophy and it also
spurred development of European WWII fighter aircraft. There's a superb
article on the subject here:

http://www.airspacemag.com/history-of-flight/schneider.html

....all seven pages of it.

Hmm, have also just spotted a typo in the original lifted article where:
"one very *course* , fixed-pitch prop..." should surely read "coarse"!

Regards,

RiŠardo

--
Moving Things in Still Pictures!

March 20th 13, 09:43 AM
On Wed, 20 Mar 2013 08:32:20 +1030, "Dave Kearton"
> wrote:

>"ŽiŠardo" > wrote in message
...
>> On 19/03/2013 19:26, Dave Kearton wrote:
>
>> Hi Dave,
>>
>> Yes, as explained to Indrek:
>>
>> "Macchi-Castoldi MC-72 Fiat AS6 engine; dual V-12, 3100 total HP,
>> each engine drives one very course, fixed-pitch prop 440.729 mph in 1934.
>> Class record still stands. Why contra-prop? Supermarine S6B w/ 2650 HP on
>> single prop overloaded one float by 32% on takeoff due to torque."
>>
>> Regards,
>>
>> RiŠardo
>>
>
>
>
>What fascinated me is the engineering work required to get the job done.
>Not only are there two unique engines inline, but the crankshafts can't be
>simply bolted together.
>
>I've been thinking about it for a while now and I can't think of a simple
>way to do it reliably.

Sounds like the designers had the same problem - didn't Ricardo
mention that two of the three examples crashed?

>All that effort and expense for a one-off design. Absolutely outstanding
>that they got it to work at all, much less in the '30s.

And how much faster would it have been without the floats?

ŽiŠardo[_2_]
March 20th 13, 10:22 AM
On 20/03/2013 09:43, wrote:
> On Wed, 20 Mar 2013 08:32:20 +1030, "Dave Kearton"
> > wrote:
>
>> "ŽiŠardo" > wrote in message
>> ...
>>> On 19/03/2013 19:26, Dave Kearton wrote:
>>
>>> Hi Dave,
>>>
>>> Yes, as explained to Indrek:
>>>
>>> "Macchi-Castoldi MC-72 Fiat AS6 engine; dual V-12, 3100 total HP,
>>> each engine drives one very course, fixed-pitch prop 440.729 mph in 1934.
>>> Class record still stands. Why contra-prop? Supermarine S6B w/ 2650 HP on
>>> single prop overloaded one float by 32% on takeoff due to torque."
>>>
>>> Regards,
>>>
>>> RiŠardo
>>>
>>
>>
>>
>> What fascinated me is the engineering work required to get the job done.
>> Not only are there two unique engines inline, but the crankshafts can't be
>> simply bolted together.
>>
>> I've been thinking about it for a while now and I can't think of a simple
>> way to do it reliably.
>
> Sounds like the designers had the same problem - didn't Ricardo
> mention that two of the three examples crashed?
>

That was the Fiat C.29: "This aircraft was designed for the 1929
Schneider Trophy air race, although did not compete in the end with the
first and second prototypes crashing, this being the third -
non-competing - sole survivor."


>> All that effort and expense for a one-off design. Absolutely outstanding
>> that they got it to work at all, much less in the '30s.
>
> And how much faster would it have been without the floats?
>

Given the lack of space for retractable undercarriage, would the
alternative be any more aerodynamically efficient?

--
Moving Things in Still Pictures!

Richard[_8_]
March 20th 13, 04:44 PM
On 3/19/2013 5:02 PM, Dave Kearton wrote:
> "ŽiŠardo" > wrote in message
> ...
>> On 19/03/2013 19:26, Dave Kearton wrote:
>
>> Hi Dave,
>>
>> Yes, as explained to Indrek:
>>
>> "Macchi-Castoldi MC-72 Fiat AS6 engine; dual V-12, 3100 total HP,
>> each engine drives one very course, fixed-pitch prop 440.729 mph in
>> 1934. Class record still stands. Why contra-prop? Supermarine S6B w/
>> 2650 HP on single prop overloaded one float by 32% on takeoff due to
>> torque."
>>
>> Regards,
>>
>> RiŠardo
>>
>
>
>
> What fascinated me is the engineering work required to get the job done.
> Not only are there two unique engines inline, but the crankshafts can't
> be simply bolted together.
>
> I've been thinking about it for a while now and I can't think of a
> simple way to do it reliably.
>
>
> All that effort and expense for a one-off design. Absolutely outstanding
> that they got it to work at all, much less in the '30s.
>

It was the early 1930s? There weren't many engines on the shelf to
chose from, and NONE that size...

The seaplane races were intended to advance aviation technology.
AND national pride was at stake here.

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