From: Iskandar Taib <ntaib@silver.ucs.indiana.edu>
Subject: Re: Napier Sabre engines (fwd)
Organization: Indiana University
Date: Wed, 14 Oct 1992 15:36:18 GMT


From Iskandar Taib <ntaib@silver.ucs.indiana.edu>


From Iskandar Taib <ntaib@silver.ucs.indiana.edu>

Here we get into the RR Crecy 2 cycle, automobiles, methanol injection,
avgas, detonation....



||||What was the RR Crecy? 
|||In my first note to you was a very short bit about this engine. Let me
|||know if you didnt get it!
||
||Hello
||
||Yes, I looked and there it was. Interesting. Do you have any horsepower
||figures for the engine? 
||
|first production units were similar in output to 60 series merlins,
|for the potential HP how about 360 HP X 12 cyls (see my note on Harry
|Ricardo's experiments) 
||
|||Yes, and a battle site also, I think. As a drop-in replacement for the
|||merlin, I shudder to think of the racket 4000 of these ((1000
|||lancastersX4 engines) would have made over germany in their nightly
|||forays! talk about pschy. war.
||
||It would have been interesting to see what a new generation of Spitfires 
||and Mustangs might have been like with this motor. When was it to have 
||been introduced?
||
||
|The Crecy was ready for production. RR also designed a fighter around
|it to maximize the use of extractor exhaust Sadly, the lead the Brits
|had in turbojet design (over US, not germany) got them to a decision
|on further piston engine R&D work as early as '41 or thereabouts. The
|decision was to go with the jets. It was the correct decision, but a
|lot of interesting piston engine stuff was stillborn. This is why the
|US piston engines developed in WW2 are interesting: they cared little
|for jets, so continued on. How they caught up is yet another
|interesting story.

|||One of the things that intrigues me about these engines (WW2 aircraft
|||engines) is that many of their features are becoming standard in cars,
|||now that US govt regs (CAFE and Emmissions) are forcing an increase in
|||engine efficiency. Several car companies, for instance, are developing
|||2-stroke engines, and of course, turbocharging, supercharging,
|||aftercooling etc. etc. were first either developed or volume produced
|||for WW2. Nitrous Oxide injection, currently the darling of the
|||performance crowd was developed by both germans and brits, primarily
|||for the photo recon wars. In fact, nitrous was obsolete by '44. The
|||germans going to pure oxygen injection, and the brits to 150 octane
|||gas, not to be confused with 115/145. Of course, octane
|||enhancement/detonation suppression is the gate through which power
|||development must be forced. We won that race, and the germans lost it,
|||sometimes by only 7 m.p.h. (87 vs 100 octane avgas) as in the Battle
|||of Britain. we can thank Standard Oil (and the US Army) for that
|||little trick. They supplied all the fuel for both sides. 
||
||Yes, I've read about how an intercooler was necessary for two-stage
||supercharging. Hmm.. was German avgas 87 octane? Seems a little low.
||I've heard how aviation engines falliong apart very quickly when de-
||tonation starts...
||

|The name of Lougheeds chief test pilot during this time escapes me,
|but his biography mentioned a series of detonation tests hecarried out
|in P38s. Plan was to establish a stable cruise at various altitudes,
|then increase the boost on a selected engine until detonation was
|encountered, then carry on until the engine blew. In many cases, the
|crankshaft with rods/pistons would be pushed out of the block, out of
|the nacelle and into space. The object was to study subsequent A/C
|action, and develop recovery methods. 
||I've also heard methanol injection being used by the Germans. 
||

|Yes, MW50 was most common, but also MW30 was used. Methanol
|50%/Water50% plus a little antirust. P&W R2800's also used this
|system, so did the brits on some merlins. One of the first production
|turbo cars (63 buick special, the same 215 ci V8 the brits still use
|in almost everything: ranfge rover etc.) used "Olds jet-fire fluid"
|which you bought for a high price from GM. This allowed a high
|compression to be used in conjunction with the turbo. I dont have to
|tell you what this fluid was, do I!
||So Standard Oil supplied gasoline to both the Germans and the British 
||during the Battle of Britain? Thats interesting indeed...

|Most german avgas was made from coal. It was quite corrosive
|apparently. Remember when, during the first arab oil embargo, it was
|reported in variuos newspapers that the methods for doing this
|conversion, although part of Americas war "booty" from germany, were
|unknown, and the info could not be found, therefor, coal could not be
|used as a base feedstock for fuel production. (I have no idea how
|difficult this process is, but I vividly remember this event) Sorry
|for the digression! by 1939, 87 octane avgas was in limited supply,
|but was generally known, at least in military circles. After some
|finagling, germany was allowed to buy several tanker loads (dont know
|how many) This "strategic" fuel was saved, and ultimately used in the
|B of B, for an extra edge. Probably because the brits were the first
|to fight the germans effectively. Anyway, the brits were able to do a
|deal at the last minute to get 100 octane (political move which the
|air corps didnt like, if I remember) This fuel was tankered from
|Standards bermuda operations. Several tankers were torpedoed, but
|their was always just enough to see them thru. RR reckoned it was good
|for 7 mph over the Me109 (f, i guess). 100 octane was, of course a
|well kept secret at the time. The whole WW2 fuel R&D program is very
|interesting, at least on the allied side.  
||
|All this is from memory, as the relevant papers are in storage, and
|unavailable, but the facts are as above

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Iskandar Taib                          |The only thing worse than Peach ala
Internet: NTAIB@SILVER.UCS.INDIANA.EDU |   Frog is Frog ala Peach
Bitnet:   NTAIB@IUBACS                 !
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