Q about WWII a/c

"Jim Macklin" wrote in message
...
In a non-pressurized aircraft, the breathing of pure oxygen
is not adequate for sustained pilot survival much above
37,000 feet. They can use oxygen delivered under pressure
to the mask, but only about 1/4 psi of "boost" to the pilot
or it will rupture the lungs.
Engines used mechanical air pumps, large turbochargers and
later they had turbo-compound engines.

Also, many of the big high altitude engines had multiple speed (at least two
speed, that I know of) gearboxes running their superchargers. Spinning the
supercharger's impellers even faster helped to build the necessary boost.

Don't forget (to the OP) that less power is needed to keep the plane going in
the air up there, because of the lessened friction.
--
Jim in NC

"Mortimer Schnerd, RN" mschnerdatcarolina.rr.com wrote

Some years ago I climbed up on the wing of a P-47 parked outside of Sun
Aviation in Vero Beach, FL and peeked into the cockpit. The manifold pressure
gauge was redlined at 67", IIRC. I was *very* impressed.

Power came from the ubiquitous R-2800 P&W aircooled engine. That was one huge
airplane... must have been about 2/3 the size of a B-17.

The first time I saw a P-47, it was taxing at our local airshow, just a few feet
away. I too was impressed at the immense bulk of the plane.

I thought to myself, that it was remarkable that it flew as well as it did!
Once again, it is proven that if you put enough HP on a brick, you can make it
fly!

That engine had a two speed supercharger, didn't it? As I recall, the impeller
is almost as large as the crankcase of the engine, and is located at the back of
the engine, in line with the crankcase. Huge, in-other-words!
--
Jim in NC

"Kingfish" wrote

I talked with the owner of a Corsair last year at the "Corsairs over
Connecticut" show at Bridgeport, CT. He said power was limited to 40"
when burning 100LL as a safety margin against detonation. I'm guessing
if 115/130 was still available then 50" would be safe. IIRC WEP (War
Emergency Power) was close to 60"

WEP also used water injection as a further deterrent against injection, didn't
it?
--
Jim in NC

Purple, lower number was equivalent octane number at a
leaned cruise setting. The higher number was for a rich
mixture at power.


"Kingfish" wrote in message
oups.com...
|
| Bob Moore wrote:
| Kingfish wrote
| I'm guessing if 115/130 was still available.....
|
| I suppose that you meant 115/145....it was 110/130.
|
| Bob Moore, a vetern of thousands of gallons of 115/145
| through R-1820s and R-3350s.
|
| Yep, can't keep the number straight any more. Was the
115/145 the
| purple stuff? BTW, what exactly did those numbers
represent?
|

On Fri, 17 Nov 2006 17:06:11 -0500, "Morgans"
wrote:


"Mortimer Schnerd, RN" mschnerdatcarolina.rr.com wrote

Some years ago I climbed up on the wing of a P-47 parked outside of Sun
Aviation in Vero Beach, FL and peeked into the cockpit. The manifold pressure
gauge was redlined at 67", IIRC. I was *very* impressed.

Power came from the ubiquitous R-2800 P&W aircooled engine. That was one huge
airplane... must have been about 2/3 the size of a B-17.

The first time I saw a P-47, it was taxing at our local airshow, just a few feet
away. I too was impressed at the immense bulk of the plane.

I thought to myself, that it was remarkable that it flew as well as it did!
Once again, it is proven that if you put enough HP on a brick, you can make it
fly!

That engine had a two speed supercharger, didn't it? As I recall, the impeller
is almost as large as the crankcase of the engine, and is located at the back of
the engine, in line with the crankcase. Huge, in-other-words!

Pretty sure it also had a turbocharger with a manual wastegate mounted
aft on the belly, and an intercooler in-between the turbocharger and
the supercharger.

TC

On Fri, 17 Nov 2006 22:40:05 GMT, wrote:

snip

Pretty sure it also had a turbocharger with a manual wastegate mounted
aft on the belly, and an intercooler in-between the turbocharger and
the supercharger.

TC

http://www.rotaryeng.net/p47turbo.jpg

wrote in message
...
On Fri, 17 Nov 2006 22:40:05 GMT, wrote:

snip

Pretty sure it also had a turbocharger with a manual wastegate mounted
aft on the belly, and an intercooler in-between the turbocharger and
the supercharger.

TC

http://www.rotaryeng.net/p47turbo.jpg

How about that! I had no idea that the jug had all of that plumbing hiding back
there in that bulk!

I thought the P-38 was somewhat unusual for having the turbo supercharger way
back in the body.

Any others that have the long plumbing? (not in a nacelle)
--
Jim in NC

The Mustang with the V1650-7 engine is limited to 55 inches on takeoff using
100LL.
Normal takeoff MP in the Jug (I only flew the N and that only once) if I
remember right, was 54 inches. The "rule" for the turbo in the 47 was that
you never got the boost ahead of the throttle. Actually, also if I remember
right, the Jug's turbocharger fed into the R2800's centrifugal supercharger
bolted onto the back of the engine.
Dudley Henriques



"Bela P. Havasreti" wrote in message
...
On Fri, 17 Nov 2006 08:02:16 -0500, "Mortimer Schnerd, RN"
mschnerdatcarolina.rr.com wrote:

Peter Duniho wrote:
This is an airplane that's only 270hp, has a boost of only about 4".
The
WWII piston airplanes had what, an order of magnitude (at least) greater
power, with boosts of anywhere from 15" to 30"? I'm no expert and I
might
have some of those numbers a bit off, but still...if my little
recreational
4-seater can get up to 25000', I don't have a hard time at all believing
that one could get a powerhouse piston fighter or bomber up to 37000'.



Some years ago I climbed up on the wing of a P-47 parked outside of Sun
Aviation
in Vero Beach, FL and peeked into the cockpit. The manifold pressure
gauge was
redlined at 67", IIRC. I was *very* impressed.

Power came from the ubiquitous R-2800 P&W aircooled engine. That was one
huge
airplane... must have been about 2/3 the size of a B-17.

Just "thinking out loud", but that sounds a bit high (67"). I'm
thinking perhaps that was the original "war emergency" limit in WW-II,
but may not be achievable with today's 100LL fuel.

Whatever the current "de-rated" maximum manifold pressure limit is
with 100LL, it still must be impressive!

Bela P. Havasreti