OT: P-51 and Bf-109

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This caught my attention. The guy doing this goes into a lot of detail about the engines, fuel and how each plane is set up for a certain role. Really interesting to watch and somewhat relevant to the Pacific when he's talking about later war higher octane fuel boosting Allied fighter performance.

Was 150 octane available and used in the Pacific?

https://www.youtube.com/watch?v=sTD7DqXfRno

Oh. And this is on the F4F. Virtually everything you'd want to learn about it.

https://www.youtube.com/watch?v=MukNZKJ8qC8

[geofflambert]

A lot have said that the P-51 was a bf-109 with range. There's some truth to that but there are plenty of differences not accounted for in that statement. What I didn't understand so well until more recently is that while FW-180s were great or at least good high altitude interceptors, at lower altitudes they were no match for Spitfires or P-51s or P-47s. The bf-109 was in action in the Spanish Civil War long before any of those others and it was still competitive to the end.

[Rusty1961]

ORIGINAL: geofflambert

A lot have said that the P-51 was a bf-109 with range. There's some truth to that but there are plenty of differences not accounted for in that statement. What I didn't understand so well until more recently is that while FW-180s were great or at least good high altitude interceptors, at lower altitudes they were no match for Spitfires or P-51s or P-47s. The bf-109 was in action in the Spanish Civil War long before any of those others and it was still competitive to the end.

It is the other way around: 190 had superior performance below 20,000 feet and the 109 beat the pants off of the 190 above 20,000 feet. The 109 G-2 could make over 400 mph at 39,000 feet. Very impressive plane for such a dated design as you point out.

[JeffroK]

100/150 octane explained
http://www.wwiiaircraftperformance.org/ ... -fuel.html

[wdolson]

By the last year of the war 150 octane avgas was widely available in the Pacific. The B-29 required it. Thanks to 150 octane fuel heavily laden B-25s from Attu were reaching the Kuriles (my father was flying with them in the summer of 1945) and PV-1s were making raids on the Kuriles too. I think the B-25s my father was flying in out of Tacloban in November 1944 (he was attached to the first B-25 unit into Tacloban after Leyte) used 150 octane too.

My father said one of the tricks guys used to like to pull was fill their lighters with 150 octane avgas then go into town and hang out in a bar waiting for someone to put a cigarette in their mouth. They would offer a light and watch the person's face when the lighter spit out a flame 1 foot high.

When some warbird recovery guys tried to rescue a B-29 from a glacier in Greenland in the 1990s, they had to find 150 octane avgas. It was hard to find by then. There was a Nova episode on it that I've never been able to bring myself to watch (the B-29 caught fire just before they were going to ferry it to Thule AFB due to some carelessness with a jury rigged fuel system for the APU. I did read the whole story in the book Hunting Warbirds which covers that as well as several other warbird recovery stories.

Bill

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ORIGINAL: wdolson


By the last year of the war 150 octane avgas was widely available in the Pacific. The B-29 required it. Thanks to 150 octane fuel heavily laden B-25s from Attu were reaching the Kuriles (my father was flying with them in the summer of 1945) and PV-1s were making raids on the Kuriles too. I think the B-25s my father was flying in out of Tacloban in November 1944 (he was attached to the first B-25 unit into Tacloban after Leyte) used 150 octane too.

My father said one of the tricks guys used to like to pull was fill their lighters with 150 octane avgas then go into town and hang out in a bar waiting for someone to put a cigarette in their mouth. They would offer a light and watch the person's face when the lighter spit out a flame 1 foot high.

When some warbird recovery guys tried to rescue a B-29 from a glacier in Greenland in the 1990s, they had to find 150 octane avgas. It was hard to find by then. There was a Nova episode on it that I've never been able to bring myself to watch (the B-29 caught fire just before they were going to ferry it to Thule AFB due to some carelessness with a jury rigged fuel system for the APU. I did read the whole story in the book Hunting Warbirds which covers that as well as several other warbird recovery stories.

Bill

Good to know. I guess the Allies don't need a late war bump in game, but it sounds like in the actual war they may have had it with the 150. Even bombers probably flying faster over target as well.

I watched that whole episode on the B-29. So tragic, and I'd had no idea what was going to happen before it did. Man, what a letdown. [:(]

[LeeChard]

I saw that documentary and did not know what was going to happen.
Heartbreaking [X(][:(]

[Chris21wen]

Here I am thinking an engines something that goes vroom. Certainly informative.

[m10bob]

ORIGINAL: wdolson



My father said one of the tricks guys used to like to pull was fill their lighters with 150 octane avgas then go into town and hang out in a bar waiting for someone to put a cigarette in their mouth. They would offer a light and watch the person's face when the lighter spit out a flame 1 foot high.



Bill

Serving in the U.S.Army, and most of us still being smokers in the very early seventies, we never bought lighter fluid.
We always opened the fuel caps on the M151 and dipped our Zippos for a "refill".

[Dili]

The advantage of P-51 over German fighters was performance at altitude. Because American bombing was at 20000kft and over. That is the major reason how war was won in the air.
Fw 190 was crap except at low level with such tiny wings, and Bf 109 was also subpar being already overweight for the tiny body, version F considered the most manageable. Speed helps but not that much when aircraft with weight increases for more power do not give good support at altitude where the air is thinner.

For Germans Ta 152 arrived too late. In crucial period of late 1943-44 they had nothing as good as Mustang or Spits, even if Spits had not enough range. They considered the Fiat G.55 the better Axis fighter by 1943 with possibility of taking bigger engines but changing it to mass production and industrial concerns and prestige meant they might as well develop a new fighter: Ta 152.

[BBfanboy]

ORIGINAL: Chris21wen

Here I am thinking an engines something that goes vroom. Certainly informative.

Fighters did have a button to inject something into the engine that gave them a sudden boost in power, but it was very hard on the engine and very short-lived in boost. I don't recall what it was that they injected into the engine.

[slpatgun]

Nitros oxide the same thing drag racers use. This plus turbocharger in the P-38 + P-47 and in the P-51 supercharges helped bring out the best in these fighters. Avgas sent to the Pacific was refined in the US at a higher octain , in the ETO the avgas octain was refined to a lower level. That is one of reasons the P-38 was not as successful in the ETO as the Allison engines needed the higher octain fuel .

[witpqs]

ORIGINAL: BBfanboy

ORIGINAL: Chris21wen

Here I am thinking an engines something that goes vroom. Certainly informative.

Fighters did have a button to inject something into the engine that gave them a sudden boost in power, but it was very hard on the engine and very short-lived in boost. I don't recall what it was that they injected into the engine.

I think it was water injection as referred to in some of the info cited above on performance tests.

[Lokasenna]

ORIGINAL: BBfanboy

ORIGINAL: Chris21wen

Here I am thinking an engines something that goes vroom. Certainly informative.

Fighters did have a button to inject something into the engine that gave them a sudden boost in power, but it was very hard on the engine and very short-lived in boost. I don't recall what it was that they injected into the engine.

Technically, "going vroom" is just going "boom" a bunch of times in very quick succession.

[witpqs]

ORIGINAL: witpqs

ORIGINAL: BBfanboy

ORIGINAL: Chris21wen

Here I am thinking an engines something that goes vroom. Certainly informative.

Fighters did have a button to inject something into the engine that gave them a sudden boost in power, but it was very hard on the engine and very short-lived in boost. I don't recall what it was that they injected into the engine.

I think it was water injection as referred to in some of the info cited above on performance tests.

How helpful you find this information is for you to determine:
https://en.wikipedia.org/wiki/Water_injection_(engine)
https://ntrs.nasa.gov/search.jsp?R=19930093596
https://en.wikipedia.org/wiki/War_emergency_power (Water injection mentioned several times in this page.)
http://www.wwiiaircraftperformance.org/ ... 3feb44.pdf ("Advance Service Bulletin No. A-255 describes the installation of water injection equipment on P-47D airplanes.")

[Lecivius]

ORIGINAL: Dili

The advantage of P-51 over German fighters was performance at altitude. Because American bombing was at 20000kft and over.

20000 k ft??!!?? [X(]

[Lokasenna]

Combat Flight Sim 2, the last great sandbox-like WW2 flight simulator that I know of, taught me about air/fuel/water mixtures. You could fiddle with them in various levels of realism modes.

[rustysi]

A lot have said that the P-51 was a bf-109 with range.

P-51's range was largely due to the addition of an 85 gallon fuel tank behind the pilot. Unfortunately it really affected the planes' trim and caused some accidents before the pilots learned how to deal with it. The trick was to burn off some of this fuel first.

Fw 190 was crap except at low level with such tiny wings,

Pretty sure its problems were solved (whether high or low altitude) with the introduction of the 190-D (Dora) version. Don't know how large the production run was, but this was a potent fighter aircraft.

I think it was water injection

My understanding as well.

[rustysi]

ORIGINAL: Lecivius

ORIGINAL: Dili

The advantage of P-51 over German fighters was performance at altitude. Because American bombing was at 20000kft and over.

20000 k ft??!!?? [X(]

25k wasn't a-typical over Europe.

[Dili]

My typo hehe. 20 kft

@ rustysi FW 190 D still had small wings the issue with BMW was indeed improved but they were fixes. The base airplane was wrong from beginning at least for the mission of superiority fighter over Germany in WW2.