World War Two Era U.S. Radial Engines (Curtiss and Pratt&Whitney)

[Lincoln Brown]

Okay, online flightsim question time.

Did the Curtiss or P&W Radial engines rotate on a mount and spin the
propellor like their WWI predecessors or were they fixed and drove a
propellor shaft?

I've seen WWI Era fighters with the engine exposed and the cylinders spin,
but
all the WWII aircraft the engine is mostly enclosed in a cowl and not
clearly visible if the cylinders are rotating as well.

Additionally, what effect if any would flying inverted for an extended
period have on a radial engine.

[Dale]

In article >,
"Lincoln Brown" > wrote:


> Did the Curtiss or P&W Radial engines rotate on a mount and spin the
> propellor like their WWI predecessors or were they fixed and drove a
> propellor shaft?

No. The engine was bolted to the airplane, the crankshaft turned with
the propellor.

> Additionally, what effect if any would flying inverted for an extended
> period have on a radial engine.

That would depend on the fuel and oil system. It they are setup so as
to provide fuel and lubrication while inverted the engine won't know the
difference (half of it is upside down all the time).

--
Dale L. Falk

There is nothing - absolutely nothing - half so much worth doing
as simply messing around with airplanes.

http://home.gci.net/~sncdfalk/flying.html

[Peter Stickney]

In article >,
"Lincoln Brown" > writes:
> Okay, online flightsim question time.
>
> Did the Curtiss or P&W Radial engines rotate on a mount and spin the
> propellor like their WWI predecessors or were they fixed and drove a
> propellor shaft?
>
> I've seen WWI Era fighters with the engine exposed and the cylinders spin,
> but
> all the WWII aircraft the engine is mostly enclosed in a cowl and not
> clearly visible if the cylinders are rotating as well.
>
> Additionally, what effect if any would flying inverted for an extended
> period have on a radial engine.

Radials, as opposed to the WW I Rotaries, are fixed, and the
crankshaft turns. Rotaries were already passing out of favor by the
end of the First World War. Improvements in construction techniques,
and in coolig fin design meant the Rotaries lost any advantage that
they had.

As for inverted flight, that would depend on the oil system of a
particular type of airplane. Radials, like their inline brethren, are
dry-sump engines - the lubricating oil is stored in a separated tank
and pumped through everything that needs it under pressure. The
limiting factor, wrt inverted flight, is the feed from the oil tank,
and cavitation in the oil pumps.

--
Pete Stickney
A strong conviction that something must be done is the parent of many
bad measures. -- Daniel Webster

[M. J. Powell]

In message >, Peter Stickney
> writes
>In article >,
> "Lincoln Brown" > writes:
>> Okay, online flightsim question time.
>>
>> Did the Curtiss or P&W Radial engines rotate on a mount and spin the
>> propellor like their WWI predecessors or were they fixed and drove a
>> propellor shaft?
>>
>> I've seen WWI Era fighters with the engine exposed and the cylinders spin,
>> but
>> all the WWII aircraft the engine is mostly enclosed in a cowl and not
>> clearly visible if the cylinders are rotating as well.
>>
>> Additionally, what effect if any would flying inverted for an extended
>> period have on a radial engine.
>
>Radials, as opposed to the WW I Rotaries, are fixed, and the
>crankshaft turns. Rotaries were already passing out of favor by the
>end of the First World War. Improvements in construction techniques,
>and in coolig fin design meant the Rotaries lost any advantage that
>they had.
>
>As for inverted flight, that would depend on the oil system of a
>particular type of airplane. Radials, like their inline brethren, are
>dry-sump engines - the lubricating oil is stored in a separated tank
>and pumped through everything that needs it under pressure.

Is that the same as a 'total-loss system'?

Mike
--
M.J.Powell

[Peter Stickney]

In article >,
"M. J. Powell" > writes:
> In message >, Peter Stickney
> > writes
>>In article >,
>> "Lincoln Brown" > writes:
>>> Okay, online flightsim question time.
>>>
>>> Did the Curtiss or P&W Radial engines rotate on a mount and spin the
>>> propellor like their WWI predecessors or were they fixed and drove a
>>> propellor shaft?
>>>
>>> I've seen WWI Era fighters with the engine exposed and the cylinders spin,
>>> but
>>> all the WWII aircraft the engine is mostly enclosed in a cowl and not
>>> clearly visible if the cylinders are rotating as well.
>>>
>>> Additionally, what effect if any would flying inverted for an extended
>>> period have on a radial engine.
>>
>>Radials, as opposed to the WW I Rotaries, are fixed, and the
>>crankshaft turns. Rotaries were already passing out of favor by the
>>end of the First World War. Improvements in construction techniques,
>>and in coolig fin design meant the Rotaries lost any advantage that
>>they had.
>>
>>As for inverted flight, that would depend on the oil system of a
>>particular type of airplane. Radials, like their inline brethren, are
>>dry-sump engines - the lubricating oil is stored in a separated tank
>>and pumped through everything that needs it under pressure.
>
> Is that the same as a 'total-loss system'?

Not quite. If the oil was being dumped overboard, it would be. Whar
usually happens is that the oil is returned to its sorage tank, &
pumped though again.
Although Wrights do have a reputation for using a lot of oil.

--
Pete Stickney
A strong conviction that something must be done is the parent of many
bad measures. -- Daniel Webster

[M. J. Powell]

In message >, Peter Stickney
> writes
>In article >,
> "M. J. Powell" > writes:
>> In message >, Peter Stickney
>> > writes
>>>In article >,
>>> "Lincoln Brown" > writes:
>>>> Okay, online flightsim question time.
>>>>
>>>> Did the Curtiss or P&W Radial engines rotate on a mount and spin the
>>>> propellor like their WWI predecessors or were they fixed and drove a
>>>> propellor shaft?
>>>>
>>>> I've seen WWI Era fighters with the engine exposed and the cylinders spin,
>>>> but
>>>> all the WWII aircraft the engine is mostly enclosed in a cowl and not
>>>> clearly visible if the cylinders are rotating as well.
>>>>
>>>> Additionally, what effect if any would flying inverted for an extended
>>>> period have on a radial engine.
>>>
>>>Radials, as opposed to the WW I Rotaries, are fixed, and the
>>>crankshaft turns. Rotaries were already passing out of favor by the
>>>end of the First World War. Improvements in construction techniques,
>>>and in coolig fin design meant the Rotaries lost any advantage that
>>>they had.
>>>
>>>As for inverted flight, that would depend on the oil system of a
>>>particular type of airplane. Radials, like their inline brethren, are
>>>dry-sump engines - the lubricating oil is stored in a separated tank
>>>and pumped through everything that needs it under pressure.
>>
>> Is that the same as a 'total-loss system'?
>
>Not quite. If the oil was being dumped overboard, it would be. Whar
>usually happens is that the oil is returned to its sorage tank, &
>pumped though again.

Right. Thanks.

Mike
-
M.J.Powell

[[email protected]]

"M. J. Powell" > wrote:

>In message >, Peter Stickney
> writes
>>In article >,
>> "Lincoln Brown" > writes:
>>> Okay, online flightsim question time.
>>>
>>> Did the Curtiss or P&W Radial engines rotate on a mount and spin the
>>> propellor like their WWI predecessors or were they fixed and drove a
>>> propellor shaft?
>>>
>>> I've seen WWI Era fighters with the engine exposed and the cylinders spin,
>>> but
>>> all the WWII aircraft the engine is mostly enclosed in a cowl and not
>>> clearly visible if the cylinders are rotating as well.
>>>
>>> Additionally, what effect if any would flying inverted for an extended
>>> period have on a radial engine.
>>
>>Radials, as opposed to the WW I Rotaries, are fixed, and the
>>crankshaft turns. Rotaries were already passing out of favor by the
>>end of the First World War. Improvements in construction techniques,
>>and in coolig fin design meant the Rotaries lost any advantage that
>>they had.
>>
>>As for inverted flight, that would depend on the oil system of a
>>particular type of airplane. Radials, like their inline brethren, are
>>dry-sump engines - the lubricating oil is stored in a separated tank
>>and pumped through everything that needs it under pressure.
>
>Is that the same as a 'total-loss system'?
>
>Mike

No, modern Radial and Inline a/c dry sump engines have a
collection system where the used oil is collected and pumped back
through the scavenge filters, the oil cooler then to the tank by
scavenge pumps. I believe the rotaries had a total loss system
where the oil was lost after use (but I'm not very knowledgeable
about them)
--

-Gord.

[Cub Driver]

>Did the Curtiss or P&W Radial engines rotate on a mount and spin the
>propellor like their WWI predecessors

No. (Am I the 1,000th or 10,000th person to answer this?)

I fly a Piper Cub with a 65 hp engine, and I have been taken off the
centerline a few times by the torque. Can you imagine what the torque
is like when the engine is turning, and not just the prop? Can you
imagine what it would be like when the horsepower gets up around 900?

all the best -- Dan Ford
email:

see the Warbird's Forum at www.warbirdforum.com
and the Piper Cub Forum at www.pipercubforum.com

[Dale]

In article >,
Cub Driver > wrote:


> I fly a Piper Cub with a 65 hp engine, and I have been taken off the
> centerline a few times by the torque. Can you imagine what the torque
> is like when the engine is turning, and not just the prop? Can you
> imagine what it would be like when the horsepower gets up around 900?

Wasn't torque that took you off the center-line, it was p-factor and
slipstream.

--
Dale L. Falk

There is nothing - absolutely nothing - half so much worth doing
as simply messing around with airplanes.

http://home.gci.net/~sncdfalk/flying.html

[Mike Marron]

>Dale > wrote:
>>Cub Driver > wrote:

>>I fly a Piper Cub with a 65 hp engine, and I have been taken off the
>>centerline a few times by the torque. Can you imagine what the torque
>>is like when the engine is turning, and not just the prop? Can you
>>imagine what it would be like when the horsepower gets up around 900?

>Wasn't torque that took you off the center-line, it was p-factor and
>slipstream.

Torque, p-factor, slipstream and gyroscopic precession are *all*
contributors to the left turning tendancies of a prop-driven aircraft.

[Mainlander]

In article >,
says...
>
> >Did the Curtiss or P&W Radial engines rotate on a mount and spin the
> >propellor like their WWI predecessors
>
> No. (Am I the 1,000th or 10,000th person to answer this?)
>
> I fly a Piper Cub with a 65 hp engine, and I have been taken off the
> centerline a few times by the torque. Can you imagine what the torque
> is like when the engine is turning, and not just the prop? Can you
> imagine what it would be like when the horsepower gets up around 900?

The rotating engines all dissappeared soon after WW1. Period.

--
Full featured open source Win32 newsreader - Gravity 2.70
http://sourceforge.net/projects/mpgravity/