Exciting to see those race birds up close
I’m sure. All sorts of things come into play when racing -
one is running the engine beyond its “normal” limits – if the
engine blows you don’t have to worry about a POW camp like the P-51 boys
did {:>) – maybe other things but not POW camp.
The fact that these guys are racing at
what? - 5000 MSL rather than 20000 MSL means they have the denser
air going for them in cooling and cooling air mass is what you want.
It is also possible to divert the boundary
layer inside the duct so that it does adversely affect the cooling. There might
be drag factors why you would want to do this. There are probably
dozens of other factors I haven’t thought of that can be brought to bear
in a “limited” production racer that simply wouldn’t be
feasible in a massed produced fighter.
However, nothing I stated should be construed
as having anything but awesome respect for what those guys can do with those
old WWII war birds as a basis.
Always wanted to make it to Reno and see them
race. The only time I was in Reno was in 1961 freezing my starving butt
off drudging up and down the snow covered mountains in Strategic Air Command
survival school conducted there at Stead AFB,NV {:>)
From: Rotary motors in aircraft
[mailto:flyrotary@lancaironline.net] On
Behalf Of Mike Wills
Sent: Monday, January 11, 2010
8:03 PM
To: Rotary
motors in aircraft
Subject: [FlyRotary] Re: P-51
Scoop (Radiator/Oil Cooler)
Cant help you there Ed, but I can tell you this. The inlet
and exit on Strega, the unlimited Reno
racer, which is a highly modified P-51, is even smaller than stock. Strega
probably produces two to three times the HP of a stock P-51. Many years ago
when first contemplating the 13B install I walked around the Reno pits with a tape measure and took a
bunch of notes (which I've long since lost).
Another interesting tidbit about Strega is the inlet
eliminates the boundary layer splitter found on the stock Mustang which is
supposed to be so necessary.
Having said all that, I still think its easier/better to
keep the cooling system under the cowl in most cases. More likely to come up
with something that works out of the box, and I'm sure it works better during
extended ground runs/taxi, something even stock Mustangs have a problem with.
Sent: Monday,
January 11, 2010 11:42 AM
Subject:
[FlyRotary] Re: P-51 Scoop (Radiator/Oil Cooler)
Boy, they really skinny down the inlets
and exits on that P 51 duct. If you ever come up with the dimensions of
the radiator I would like to know them. I’d like to try and
calculate some of the airflow parameters in the duct while at 400 + Mph to see
how much power it would theoretically dissipate based on air flow alone..
Ed
From: Rotary motors in aircraft
[mailto:flyrotary@lancaironline.net] On
Behalf Of Thomas Mann
Sent: Monday, January 11, 2010
11:58 AM
To: Rotary
motors in aircraft
Subject: [FlyRotary] P-51 Scoop
(Radiator/Oil Cooler)
I’m still on
my quest for information to improve on my design of my P-51 scoop. I did acquire
an accurate drawing that is a true scale rendering of the scoop and the
diffuser. I figured I’d better share it. It’s a little difficult to
find.
I apologize for the
quality of the drawing. It’s a print from digital rendering from a
microfiche of the original blueprints from North American. It’s enough
for me to transfer to CAD and then scale to my application. Interesting stuff.
I scaled it down but
it’s too big to attach so please use the link below:
http://forum.canardaviation.com/attachment.php?attachmentid=4674&d=1263224869
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