Use of 150 octane fuel in the Merlin (Xylidine additive etc etc)

In article , Peter Stickney
writes
In article ,
Dave Eadsforth writes:


Good day, good people,

I wondered if anyone out there (in all probability, Peter!) could help
me understand more fully the process by which the Merlin engine was
enabled to use 150 octane fuel; one feature of which was the addition of
the Xylidine anti-knock compound. (This was touched on in a thread
last year, I recall.)

If you can wait, I've got to dig out some files & make sure of some
references, but I'll have a comprehensive answer in about a day's
time. In the meantime, I'll chuck out a tidbit or two.

SNIP of much appreciated theoretical and practical stuff


Thanks, Peter; that summary has given me a pretty firm grasp of the
essentials for boosting engines. If you do have any additional material
that would be great.

I have recently seen some stuff on the lengths that the Germans went to
to get the Ju86 to fly at high altitude. I had not realised previously
that nitrous oxide could be used with a diesel engine - but the Ju86P
did for its (1,000 HP) Jumo 207B-3s.

Re. diesel engines and the energy it takes to supercharge; that would
explain the planned construction of the Ju86R-3, not just with more
powerful engines (1500 HP Jumo 208s) but also installing the two stage
blower for these within the Ju86 fuselage and driving it with a separate
engine - a supercharged DB 605.

I have pondered why it was that the Luftwaffe did not try to boost the
Ju86R-1s and 2s a bit more in early 1944, when they needed to see what
the allies were doing on the south coast of England, and hence could
have used a recce plane that had a good chance of getting home with the
goods. Perhaps the Jumo 207s had already been boosted to the limit...

Cheers,

Dave

--
Dave Eadsforth