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VMF-214_HaVoK
08-27-2005, 06:37 PM
One interesting historical issue involving octane rating took place during (Click link for more info and facts about WWII) WWII. (A republic in central Europe; split into East German and West Germany after World War II and reunited in 1990) Germany received nearly all her oil from (A Balkan republic in southeastern Europe) Romania, and set up huge distilling plants in Germany to produce petrol from coal. In the (North American republic containing 50 states - 48 conterminous states in North America plus Alaska in northwest North America and the Hawaiian Islands in the Pacific Ocean; achieved independence in 1776) US the oil was not "as good" and the oil industry instead had to invest heavily in various expensive boosting systems. This turned out to be a huge blessing in disguise. US industry was soon delivering fuels of ever-increasing octane ratings by adding more of the boosting agents, with cost no longer a factor during wartime. By war's end American aviation fuel was commonly 130 to 150 octane, which could easily be put to use in existing engines to deliver much more power by increasing the compression delivered by the (Compressor that forces increased oxygen into the cylinders of an internal-combustion engine) superchargers. The Germans, relying entirely on "good" petrol, had no such industry, and instead had to rely on ever-larger engines to deliver more power.

However, someone pointed out that: German aviation engines were of the direct fuel injection type and could use emergency methanol-water and nitrous-oxide injection, which gave 50% more engine power for 5 minutes of dogfight. This could be done only five times and then the aero engine went to the scrapyard (or after 40 hours run-time, whichever came first). Most German aero engines used 87 octane fuel (called B4), some high-powered engines used 100 octane (C2/C3)fuel.


Another pointed out in reply that: This historical "issue" is based on a very common misapprehension about wartime fuel octane numbers. There are two octane numbers for each fuel, one for lean mix and one for rich mix, rich being always greater. So, for example, a common British aviation fuel of the later part of the war was 100/125. The misapprehension that German fuels have a lower octane number (and thus a poorer quality) arises because the Germans quoted the lean mix octane number for their fuels while the Allies quoted the rich mix number for their fuels. Standard German high-grade aviation fuel used in the later part of the war (given the designation C3) had lean/rich octane numbers of 100/130. The Germans would list this as a 100 octane fuel while the Allies would list it as 130 octane.


After the war the US Navy sent a Technical Mission to Germany to interview German petrochemists and examine German fuel quality, their report entitled "Technical Report 145-45 Manufacture of Aviation Gasoline in Germany" chemically analysed the different fuels and concluded "Toward the end of the war the quality of fuel being used by the German fighter planes was quite similar to that being used by the Allies".

http://www.absoluteastronomy.com/encyclopedia/p/pe/petrol.htm

VMF-214_HaVoK
08-27-2005, 06:37 PM
One interesting historical issue involving octane rating took place during (Click link for more info and facts about WWII) WWII. (A republic in central Europe; split into East German and West Germany after World War II and reunited in 1990) Germany received nearly all her oil from (A Balkan republic in southeastern Europe) Romania, and set up huge distilling plants in Germany to produce petrol from coal. In the (North American republic containing 50 states - 48 conterminous states in North America plus Alaska in northwest North America and the Hawaiian Islands in the Pacific Ocean; achieved independence in 1776) US the oil was not "as good" and the oil industry instead had to invest heavily in various expensive boosting systems. This turned out to be a huge blessing in disguise. US industry was soon delivering fuels of ever-increasing octane ratings by adding more of the boosting agents, with cost no longer a factor during wartime. By war's end American aviation fuel was commonly 130 to 150 octane, which could easily be put to use in existing engines to deliver much more power by increasing the compression delivered by the (Compressor that forces increased oxygen into the cylinders of an internal-combustion engine) superchargers. The Germans, relying entirely on "good" petrol, had no such industry, and instead had to rely on ever-larger engines to deliver more power.

However, someone pointed out that: German aviation engines were of the direct fuel injection type and could use emergency methanol-water and nitrous-oxide injection, which gave 50% more engine power for 5 minutes of dogfight. This could be done only five times and then the aero engine went to the scrapyard (or after 40 hours run-time, whichever came first). Most German aero engines used 87 octane fuel (called B4), some high-powered engines used 100 octane (C2/C3)fuel.


Another pointed out in reply that: This historical "issue" is based on a very common misapprehension about wartime fuel octane numbers. There are two octane numbers for each fuel, one for lean mix and one for rich mix, rich being always greater. So, for example, a common British aviation fuel of the later part of the war was 100/125. The misapprehension that German fuels have a lower octane number (and thus a poorer quality) arises because the Germans quoted the lean mix octane number for their fuels while the Allies quoted the rich mix number for their fuels. Standard German high-grade aviation fuel used in the later part of the war (given the designation C3) had lean/rich octane numbers of 100/130. The Germans would list this as a 100 octane fuel while the Allies would list it as 130 octane.


After the war the US Navy sent a Technical Mission to Germany to interview German petrochemists and examine German fuel quality, their report entitled "Technical Report 145-45 Manufacture of Aviation Gasoline in Germany" chemically analysed the different fuels and concluded "Toward the end of the war the quality of fuel being used by the German fighter planes was quite similar to that being used by the Allies".

http://www.absoluteastronomy.com/encyclopedia/p/pe/petrol.htm

Grey_Mouser67
08-27-2005, 09:19 PM
Hmmm....so the US really DID have 150 octane fuel in their "Late" aircraft while the Luftwaffe had only 87 octane in their "Late" aircraft.... http://forums.ubi.com/images/smilies/59.gif

Guess it will be a matter of time before we get a P-51D late and a Spitfire MkIXe late http://forums.ubi.com/images/smilies/88.gif