P-51D 150 Octane Test Flight Data?

[jsw225]

Hi guys!

I'm looking for test flight data on the P-51D using 150 octane fuel. So far I've come up with data on the P-51B 1650-3 using 150 Octane Fuel, and the P-51B 1650-7 using 150 octane fuel, but nothing on the P-51D 1650-7.


Does anyone have anything? Any help is greatly appreciated.

 

[Neil Stirling]

Mustang IV/P51D Mustang IV Flight Trials

Neil.

 

[Dan Fahey]

Interesting that NAA tests on the P51A Mustang using something between 52 to 59 inches of boost at the time could hit 415 mph at 10400 ft.
Still flying at 408 mph at 17500 ft. Yet British operated all the Allison Mustangs at 72 inches but no documentation what speeds it obtained.
My point is that the US and British operated the B an D Mustang and Spitfire with 150 octane fuels to chase V1 rockets.
The tests show the same speeds at 25 psi or 70/72 inches. Seems to me that the P51A would have made a better faster interceptor.

 

[Dan Fahey]

Interesting that NAA tests on the P51A Mustang using something between 52 to 59 inches of boost at the time could hit 415 mph at 10400 ft.
Still flying at 408 mph at 17500 ft. Yet British operated all the Allison Mustangs at 72 inches but no documentation what speeds it obtained.
My point is that the US and British operated the B an D Mustang and Spitfire with 150 octane fuels to chase V1 rockets.
The tests show the same speeds at 25 psi or 70/72 inches.

 

[Shortround6]

Not sure what you are asking.

The Allison Mustangs could only pull 70-72in at sea level (or darn close,like a few hundred feet) and at high speed, but then you have the drag of the thick air at sea level.
The supercharger could only deliver around 60in pressure at 10,000ft and at 18,000ft it was down to about 42-42 in. for an engine using 9.60 gears. Engines using 8.80 gears lost pressure with altitude quicker.
Please note these are in high speed level flight.

When at climb speed the engine could only hold 57in to about 6,000ft and at 10,000ft it was down to 50.0 inches and at 18,000ft it was down to 38 inches.

I would also note again that these figures are for an engine using 9.60 gears and these engines were seldom, if ever, run at a 70-72in. Those engines that were run at those pressures were the 8.80 gear engines. A test of an Allison Mustang using those gears shows 60in at 4400ft, 50in at 10,000ft and 36 1/2in at 18,000ft in high speed level flight, and 60in at 800ft (yes 800) at climb speed, 45in at 10,000ft and 34in at 18,000ft.

see: Mustang II Performance Trial

The air at 18,000ft is about 57% as dense as it is at sea level so you only need 57% as much power to go just as fast. (any of our more knowledgeable people on aerodynamics are welcome to correct me on that).

by the way, 25lbs boost is a lot closer to 80 inches of MAP. 14.7lbs=29.92 inches so 25lbs of boost (25lbs over the standard 14.7) is 80.80 inches.

 

[Dan Fahey]

Not sure what you are asking.

The Allison Mustangs could only pull 70-72in at sea level (or darn close,like a few hundred feet) and at high speed, but then you have the drag of the thick air at sea level.
The supercharger could only deliver around 60in pressure at 10,000ft and at 18,000ft it was down to about 42-42 in. for an engine using 9.60 gears. Engines using 8.80 gears lost pressure with altitude quicker.
Please note these are in high speed level flight.

When at climb speed the engine could only hold 57in to about 6,000ft and at 10,000ft it was down to 50.0 inches and at 18,000ft it was down to 38 inches.

I would also note again that these figures are for an engine using 9.60 gears and these engines were seldom, if ever, run at a 70-72in. Those engines that were run at those pressures were the 8.80 gear engines. A test of an Allison Mustang using those gears shows 60in at 4400ft, 50in at 10,000ft and 36 1/2in at 18,000ft in high speed level flight, and 60in at 800ft (yes 800) at climb speed, 45in at 10,000ft and 34in at 18,000ft.

see: Mustang II Performance Trial

The air at 18,000ft is about 57% as dense as it is at sea level so you only need 57% as much power to go just as fast. (any of our more knowledgeable people on aerodynamics are welcome to correct me on that).

by the way, 25lbs boost is a lot closer to 80 inches of MAP. 14.7lbs=29.92 inches so 25lbs of boost (25lbs over the standard 14.7) is 80.80 inches.

I am reading the British Tactical use of the Mustang 1. They removed the automatic boost controls and in combat operated at 72 inches a good bit. Russians and CBI did the same to the P40s.

My issue is that no speed tests were done at this boost level. Second did the British and US use the British 100/130 octane fuels in CBI and Africa?

 

[mad_max]

Found this link which maybe of help.

Estimating Aircraft Speed Increases through Additional Power

The US made their own 100/130. It wasn't just a British thing.

 

[Shortround6]

Found this link which maybe of help.

Estimating Aircraft Speed Increases through Additional Power

The US made their own 100/130. It wasn't just a British thing.

It was a joint specification so the fuel would be interchangeable. Unlike early US 100 octane and British 100 octane fuel in 1940 and some of 1941 which were not interchangeable. British fuel would dissolve rubber components in the fuel system of American aircraft.

There were at least 3 different specifications for 100/130 fuel. The ones I know of changed the amount of lead that could be used, starting at 3 cc per gallon, then 4 cc per gallon and finally 4.6 cc per gallon. While each increase allowed more fuel per barrel of crude each increase in lead had to balanced against a greater tendency to lead foul the spark plugs (might require a different type of spark plug depending on the engine) or other problems. The last change may have been the one that allowed for more use of heavy aromatic compounds that caused so much trouble in the P-38.

 

[mad_max]

"The overall numbers tell only part of the picture. By 1942, Britain imported 78.2% of its high octane aviation fuel and 80.0% of its other aviation fuel from the US. "

 

[Dan Fahey]

It was a joint specification so the fuel would be interchangeable. Unlike early US 100 octane and British 100 octane fuel in 1940 and some of 1941 which were not interchangeable. British fuel would dissolve rubber components in the fuel system of American aircraft.

There were at least 3 different specifications for 100/130 fuel. The ones I know of changed the amount of lead that could be used, starting at 3 cc per gallon, then 4 cc per gallon and finally 4.6 cc per gallon. While each increase allowed more fuel per barrel of crude each increase in lead had to balanced against a greater tendency to lead foul the spark plugs (might require a different type of spark plug depending on the engine) or other problems. The last change may have been the one that allowed for more use of heavy aromatic compounds that caused so much trouble in the P-38.

What did we use in 1942 New Guinea? Just finished reading p39/Zero New Guinea 1942 Mike Claringbould. Seems the shoot down record was 15 each side.

 

[Shortround6]

"The overall numbers tell only part of the picture. By 1942, Britain imported 78.2% of its high octane aviation fuel and 80.0% of its other aviation fuel from the US. "

You could very well be correct, I don't have the numbers of total gallons or barrels or tons from each source.

But I would note that you have to be fairly careful when reading about sources because to the British anything that came from North America, South America or the caribbean came from "the Americas" which is quite different than saying product X came from America (without the "S").

At the beginning of WW II Royal Dutch Shell had the biggest refinery in the world in Curacao, the largest refinery in the British commonwealth is in Trinidad and there was another large refinery in Dutch owned Aruba. All of which would be considered coming from "the Americas"

Like I said you could be right about around 80% coming form the US and around 20% coming from the Caribbean, I don't know, but the US while it deserves a lot of credit, sometimes gets a bit more than it deserves.

There were also refineries in England that processed crude oil. I believe at least one, if not more, did make batches of 100 octane just to see if they could but much more often were making lower grade fuels.

 

[Dan Fahey]

You could very well be correct, I don't have the numbers of total gallons or barrels or tons from each source.

But I would note that you have to be fairly careful when reading about sources because to the British anything that came from North America, South America or the caribbean came from "the Americas" which is quite different than saying product X came from America (without the "S").

At the beginning of WW II Royal Dutch Shell had the biggest refinery in the world in Curacao, the largest refinery in the British commonwealth is in Trinidad and there was another large refinery in Dutch owned Aruba. All of which would be considered coming from "the Americas"

Like I said you could be right about around 80% coming form the US and around 20% coming from the Caribbean, I don't know, but the US while it deserves a lot of credit, sometimes gets a bit more than it deserves.

There were also refineries in England that processed crude oil. I believe at least one, if not more, did make batches of 100 octane just to see if they could but much more often were making lower grade fuels.

Also Burma oil and why Chennault and Brits we're protecting so hard !

 

[mad_max]

You could very well be correct, I don't have the numbers of total gallons or barrels or tons from each source.

Like I said you could be right about around 80% coming form the US and around 20% coming from the Caribbean, I don't know, but the US while it deserves a lot of credit, sometimes gets a bit more than it deserves.

On many things you are correct about the US gets more credit than is due. I always correct people when I hear about the US won the War. I'd say the Soviet Union deserves more credit than it gets. The bottom line is without the sum total of all Allied involved the world more than likely would be much different today.

 

[jmcalli2]

Hi guys!

I'm looking for test flight data on the P-51D using 150 octane fuel. So far I've come up with data on the P-51B 1650-3 using 150 Octane Fuel, and the P-51B 1650-7 using 150 octane fuel, but nothing on the P-51D 1650-7.


Does anyone have anything? Any help is greatly appreciated.

Some similar items:
http://www.wwiiaircraftperformance.org/150grade/appendixa.pdf

http://www.wwiiaircraftperformance.org/mustang/p-51b-160grade.pdf

http://www.wwiiaircraftperformance.org/p-38/Allison_V-1710-91_ENG-57-531-267.pdf

 

[Laurelix]

P-51C with no Wing racks (Completely clean)
Could do 406mph (653km/h) at Sea Level at +25lbs / 81Hg boost
Its optimal max speed with 81Hg tho is only around 1000 metres above sea level at which it hits around 413.5mph (665km/h)

I would imagine P-51D is roughly the same

 

[Mike Williams]

Level speed performance of a P-51D with increased boost, allowable with 150 grade fuel, derived from flight tests conducted at Wright Field, Dayton, Ohio, on the P-51D-15NA airplane, AAF No. 44-15342.

 

[CORSNING]

Excellent information Mike. I am putting together performance/specifications
charts on excel for all WW2 fighter aircraft. This information on the P-51D-15
is a great addition. Mike, would you happen to have any specifications on 44-
15342 during this test and possibly climbing performance?

Any additional information is greatly appreciated, Jeff

 

[Mike Williams]

Excellent information Mike. I am putting together performance/specifications
charts on excel for all WW2 fighter aircraft. This information on the P-51D-15
is a great addition. Mike, would you happen to have any specifications on 44-
15342 during this test and possibly climbing performance?

Any additional information is greatly appreciated, Jeff

Thanks Jeff, please see: Flight Tests on the North American, P-51D Airplane, AAF No. 44-15342. "High speed and climb performance have been obtained on this airplane at a take-off gross weight of 9760 pounds. Performance was obtained up to an altitude of 35,000 feet in increments of 5000 feet in a clean configuration. The clean configuration included one external bomb rack on each wing." Extrapolated climb curves with the increased MAP are shown below.

 

[CORSNING]

Mike, excellent graphs. Do you have any point references at sea level or
supercharger changes for the climb graph? It is a little difficult to read for
these old eyes of mine and I do not wish to make any mistakes if possible.

I am very familiar with the P-51D test report on your site.
Thank you for the added information Mike.

All the best, Jeff

 

[Mike Williams]

Mike, excellent graphs. Do you have any point references at sea level or
supercharger changes for the climb graph? It is a little difficult to read for
these old eyes of mine and I do not wish to make any mistakes if possible.

I am very familiar with the P-51D test report on your site.
Thank you for the added information Mike.

All the best, Jeff

Hi Jeff, these are my numbers for the curves for 150 grade fuel boost levels:

Which graphs like so: