WIX Archives

Re: A seemingly simple powerplant question

Posted by Ron Henry on Thu Jan 17, 2002 07:43:47 AM

In reply top Re: A seemingly simple powerplant question posted by Christer on Wed Jan 16, 2002 08:20:31 PM

: Scott,
: a long time ago I read in a book, I can?t remember which,
: that in the early 1930's a german delegation was invited t
: o visit Rolls Royce. This was at the time when the PV12,
: later renamed the Merlin, was still in it?s initial develo
: pment phase. An inverted design had been considered and ab
: andoned but they still had the wooden mock-up. This was pu
: t on display for the germans to see while the up-right des
: ign was tucked away out of sight.
:
: The initial decision to invert the engine was taken in agr
: eement with the Air Ministry to provide improved vision fo
: r the pilot, plus other sound technical reasons. When the
: mock-up was revealed to the airframe designers they were t
: otally opposed to the idea since it, for them, involved to
: o many design problems since their current projects were c
: onceived with an up-right engine in mind. This was the rea
: son for abandoning the inverted design.
:
: I can?t remember which the "sound technical reasons" were
: but, I don?t think direct fuel injection was a prerequisit
: e. Rolls Royce never used direct fuel injection. They alwa
: ys injected into the supercharger to take advantage of the
: charge cooling effect.
: A prerequisite would be a dry sump oil system with scaveng
: e pumps to return the oil from the rocker covers to a tank
: .
: If memory serves me correctly the german guns, mounted in
: the nose with the breeches protruding into the cockpit, we
: re manually cocked and that operation would be kind of awk
: ward doing down at ones feet. If there was a stoppage the
: guns could be cleared by the pilot.
:
: The bit about "showing the germans the inverted PV12" is p
: robably a wartime propaganda variant of the answer to Your
: question which I?m sure was asked at that time too but, b
: e that as it may, it would be my favourite answer.
:
: Regards,
: Christer


You gotta have a scavenge pump, dry sump and external oil tank whatever type of aero engine you have, or you stand an excellent chance of wrecking your bearings when manoeuvering or pulling some G !!

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