Fuel Octaine and German and Japanese engine performance

[brady]

 I have a Question, now this may be a dumb one but, I was under the impression that German aviation gas was around 87 octane, now they had some of the best performing aircraft of the war. So why are we figuring that the Japanese aircraft that burned a lower grade of octane fuel than our own should have a diminished performance level, is it because they were designed to operate on a higher octane fuel and that as the war progressed they not able to get that fuel do to fuel shortages?

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[This message has been edited by brady (edited 03-17-2001).]

[This message has been edited by brady (edited 03-17-2001).]

[wells]

Using higher octane fuel allows higher manifold pressures to be used, thus giving more horsepower out of the engine.  The Japanese may well have used 85 octane fuel during the war, whereas the US was using 100 and finally 115 grade fuel, so a question arises when it comes to modelling the Japanese planes as to what fuel grade was used during the flight tests.  Is the data original Japanese data or is it US data from captured aircraft, where the fuel grade may have been higher?

[Tac]

N1k uses pure & distilled antimatter. Dinnae need no loving fossil fuel.  

This is a good question, is AH modeling the planes as they performed during the war or are they basing their data on test flights made after the war (or on the test data of the country that made the A/C... which probably used high octane gas for its tests).

Any comments HTC?  

[Grumble]

Interesting, let me add little more light on the Japanese planes.  In the TAIC manual on Japanese A/C performance and characteristics, the Ki-61-Ib is said to use 92 octane yet her engine is a licensed and only slightly modified version of the German DB601 which only needs 92 octane.  Very interesting indeed isnt it  ?

All other Japanese A/C in the same manual are listed as 92 as well. however, a few mention 87 + Methanol (like the Ki44 TOJO and a few bombers).

BTW TAIC stands for Technical Air Intelligence.  This book is very interesting, it is available from the following:
 www.historicaviation.com  www.aeroplanebooks.com

I think they are correct addresses.

Take Care,

KNOCK

[LLv34_Snefens]

"The Ki-61-Ib is said to use 92 octane yet her engine is a licensed and only slightly modified version of the German DB601 which only needs 92 octane."

Is this a typo? What uses 92 octane, and what are the other using then?

[Grumble]

Yeah it was a typo:  The 109's DB01 uses 87 octane and the Ki-61 was 92.

Sorry for the misunderstanding.

Thanks!

KNOCK