manifold pressure

Flight Training and topics related to getting your licence or ratings.
User avatar
Colonel
Posts: 2424
Joined: Wed Jan 15, 2020 10:02 pm
Location: Over The Runway



Not sure we're allowed to talk about that. Anyone remember an F-14A?

You can hear the screaming LSO and the engine spooling up just before the ramp strike.


As God as my witness, I thought turkeys could fly.
Big Pistons Forever
Posts: 202
Joined: Tue Feb 02, 2021 11:05 pm

Ummmm, what does the F35 crash have to do with manifold pressure?
User avatar
Colonel
Posts: 2424
Joined: Wed Jan 15, 2020 10:02 pm
Location: Over The Runway

The subject changed to the dangers of flight training.
As God as my witness, I thought turkeys could fly.
CaptNerdly
Posts: 14
Joined: Thu Jan 16, 2020 4:01 am

Think I read somewhere that the spitfire wing was designed by Beverly Shenstone (a canadian). Mitchell (dead guy) gets all the credit for the spitfire but Joe Smith developed it into a war winner after Mitchell's untimely death.
User avatar
Colonel
Posts: 2424
Joined: Wed Jan 15, 2020 10:02 pm
Location: Over The Runway

The Spitfire changed drastically over the years from the initial version
to the much heavier, powerful versions later in the war.

I remember one of the Air Marshalls (Johnny Johnson?) in his biography
wrote that one day a nice young man showed up to take his personal
Mark V to be destroyed - it was six months old, and obsolete - and replaced
with a newer, heavier, more powerful version.

He said he preferred the Mark V, and missed it. Read his biography 40 or
50 years ago.

Feel free to burn me at the stake, but I don't really like the liquid cooled V-12
WWII fighters. My friend Mike tells me it's a bummer when you go to the airport
to go flying, and you see coolant on the hangar floor underneath your Spitfire.
And honestly, they sound kind of flatulent, flying by.

I would prefer the P-47 or a Corsair with a big beautiful reliable air-cooled radial
engine, but I was dropped on my head as a small child.

The P-47 doesn't get much love like the pretty girls (Spitfire, P-51) but
it was actually a very effective multi-role aircraft, if you look at the numbers,
and you couldn't take it down with a .22 like a P-51 or Spitfire.

If all you ever do in aviation is own/fly a P-47 or Corsair, how much have
you really missed out on?

Another subject .. (Canadians that never get any credit) ... I might mention
Max Aitken. No one knows who he is (Lord Beaverbrook) but he was cruicial
to the success of Britain in WWII. From Maple, Ontario. Not that anyone
would know that, or even know of him. I am sure he made plenty of enemies -
he got things done.

People that won WWII. Max Aitken, Alan Turing. No one knows of them, no
one cares. Oughta be statues of them in every village square of the British
Empire. Didn't exactly work out that way. Lots of hate for Alan Turing - he
was different, and that's very dangerous. He saved more lives than any General,
and he was hated and prosecuted.
Winston Churchill said that Turing made the single biggest contribution to Allied victory in the war against Nazi Germany.

Turing died in 1954 ...

In 2009, following an Internet campaign, British Prime Minister Gordon Brown made an official public apology on behalf of the British government for "the appalling way he was treated".

Queen Elizabeth II granted Turing a posthumous pardon in 2013.
Atrocious.

It is perhaps a sign of the decline of our civilization that we worship morons
that never graduated high school (Hollywood Elites) but we ignore the people
who ought to be celebrated for their unbelievable, unprecedented successes
that benefit us all.

For example, there is one prolific engineer I know, he has fundamentally affected
your life for so much the better with a multitude of fantastic, historic achievements,
and you don't even know his name. You ought to be ashamed.
As God as my witness, I thought turkeys could fly.
Squaretail
Posts: 431
Joined: Wed Apr 28, 2021 7:21 pm
Location: Group W Bench

I remember one of the Air Marshalls (Johnny Johnson?) in his biography
wrote that one day a nice young man showed up to take his personal
Mark V to be destroyed - it was six months old, and obsolete - and replaced
with a newer, heavier, more powerful version.
One could only imagine what kind of wear and tear actual combat would put on an airframe, especially ones that weren't really built to last. Wasn't there a lot of magnesium used in Spitfire parts? Sitting outside on the English countryside, which is practically all coastal humidity?

The P-47 doesn't get much love like the pretty girls (Spitfire, P-51) but
it was actually a very effective multi-role aircraft, if you look at the numbers,
and you couldn't take it down with a .22 like a P-51 or Spitfire.
To be fair, I don't think .22s were much of a concern, since both the Germans and Japanese were fond of equipping their aircraft with 20mm weapons to which few aircraft of the time could stand up to many hits from. OF note, the British quickly got away from .303 caliber weapons due to their ineffectiveness in air combat, even with 8 of them.

I think there's enough love for the P-47, after all, there was no mustang II or Spitfire II, but they saw fit to have a Thunderbolt II. Personally one of the prettiest WWII aircraft is the P-36 Hawk. I think there's an all metal finished one still flying. Its gorgeous. That said, my favorite will remain the Typhoon. That scoop, and H-block for the win. Pure awesomeness. Sounds like nothing else.
The details of my life are quite inconsequential...
Jamesel
Posts: 14
Joined: Wed Apr 28, 2021 1:24 am

Quote „ Personally one of the prettiest WWII aircraft is the P-36 Hawk. I think there's an all metal finished one still flying“


Planes of Fame in California has a P-36
Image

The polish really does add a lot….

The Fighter Collection at Duxford has a Hawk 75. Image

Both fly on occasion.
Big Pistons Forever
Posts: 202
Joined: Tue Feb 02, 2021 11:05 pm

TwinOtterFan wrote:
Tue Feb 01, 2022 1:48 am
Hey all, I am struggling a bit with manifold pressure and constant speed props. Wondering if anyone happens to know a good resource to understand the basics?
The prop is like the gearshift (RPM) the throttle is like the gas pedal (MP)

You can step on the gas in any gear. ( thread digression, when I was in Uni I had a Chevrolet Vega that a guy had dropped a crate 350, Munci 4 speed and a narrowed 12 bolt rear end. You could floor it in 4 th gear from a dead stop. It was a all white and a real sleeper. I lost count of the number of blow dried asshats with the big chicken on the hood who got to see my tail lights getting closer together :mrgreen: )

Anyway back to the thread topic. You want high RPM when you need to accelerate (takeoff, climb), ie 1 st gear . You want low RPM when you cruise ie 4 th gear

From a practical perspective, more power is right to left on the knobs ( mixture richen, prop increase RPM, throttle increase MP ) . Reducing power is left to right.

Finally your homework. You are flying along in your constant speed prop equipped airplane and see the RPM start to hunt up and down, what is the first gauge you should look at ?
User avatar
Colonel
Posts: 2424
Joined: Wed Jan 15, 2020 10:02 pm
Location: Over The Runway

a Chevrolet Vega that a guy had dropped a crate 350
Oh dear. The poor Vega. They tried to make a sleveless aluminum block,
but the cylinder coatings just weren't there yet, and the blue smoke. They
made more smoke than I do!

Image

Syncing the props isn't easy, but see the basic physics here:

https://en.wikipedia.org/wiki/Beat_(acoustics)

Back to smoking cars. I know there were people putting big blocks in Vegas
and Chevettes (now there's a car you don't see much any more) ...

But I always was a fan of the Chevy Monza. Again, it got no respect, but
it had an interesting history. HUGE engine compartment - totally different
than the early Mustangs - for a Wankel engine that GM paid $$$ for and
never shipped. Odd. Mazda figured out the RX-7 and boy could it rev ...

Image

Anyways, back to the Monza. Not a bad looking car (not a great looking
car) but it was light weight and CHEAP it came with a POS Chev 305 V-8
which could be easily swapped (Jeff Lutz did it overnight) out for a clone
350 LT-1 putting out 350hp and 350 ft-lbs of torque.

With a manual transmission and a warmed-up 350 the Chevy Monza was
a lot of car for not much money, in the dark days of the early 1980's. Brought
to you by John DeLorean, who the government destroyed by convicting him
of crime that they invented. Much like today's "process" crimes (Flynn, Stone).

Recently, my heroes Freiburger and Finnegan, with the help of Jeff Lutz put
5 leaf blowers into an old, clapped out V-8 Monza and went 132 mph on a
runway which Finnegan got shit on for.

Anyways, those days are four decades in the past, but a small-block swap
on a Monza was really easy, gave GREAT performance for peanuts, back in
the days when the Left ruled and cars sucked.
blow dried asshats with the big chicken on the hood
Now, now. Fred sold a lot of cars. Don't be dissin' my dog, now :^)

Image

I know, all three are dead now, but they were worth 3 million snowflakes.
As God as my witness, I thought turkeys could fly.
Post Reply