Talk:Rolls-Royce Merlin

Recent adds

Good stuff folks but I am worried that an unencyclopaedic level of detail is creeping in, particularly in the 'Variants' section. Why not add this information to the dedicated main article; List of Rolls-Royce Merlin variants? It's hardly been edited since it was split off, room for lots of expansion there. Cheers. Nimbus (Cumulus nimbus floats by) 21:23, 29 December 2010 (UTC)

Adjusting 1940 price to 2010 values

Please don't bother adjusting the 1940 price to 2010 figures: for one thing does the Wiki template calculate according to the retail price index (RPI), or GDP? Such figures are always variable and can be different, according to the formula used to calculate relative values. Without adding a note explaining how the calculated figures are arrived at it is simply an added complication and not worth using in an article meant to be read by the general public. See also this external website which explains some of the variations...Minorhistorian (talk) 20:38, 19 January 2011 (UTC)

I would agree, interesting though the figure might be. I visited the template documentation and there is not much indication on how these figures are derived, scope for original research and wild variation there. I'm glad that you reverted as it was also presented in a very strange way; £80.9 thousand I think it was. Few, if any, would understand this format (should be plain £80,900) and it also conflicted with the format of the existing figure ('000' vice 'thousand' in words), not desirable in an FA level article.

What would be more interesting and relevant is the asking price of an overhauled Merlin today, there is definitely room in the article text for this (not the infobox) or as a footnote. With Spitfires now in the £1,000,000 to £1,500,000 range (I believe), I would hazard a guess that a 'new' Merlin would cost at least £200,000. Just need a reliable source to verify it. Nimbus (Cumulus nimbus floats by) 00:01, 20 January 2011 (UTC)

Agree, a current/recent sales price would be interesting & more relevant. I'm no fan of inflation templating that far back in any case, since it ignores contemporary buying power & changes in exchange rates, & implies a price equivalence where none exists. Compare it to the price of a V1710 or a Model A, or something, if you must give it a relative value. TREKphiler ^{any time you're ready, Uhura} 01:41, 20 January 2011 (UTC)

During the war both engines and aircraft were built to government contract in various, sometimes government-owned, 'shadow' factories, so any attempt at giving a meaningful 'market' price is prone to errors. This is why a Lancaster was only reckoned to cost around £55,000, but the actual cost if someone else had wanted to buy one would have been much higher. Also, what exchange rate would one use, today's, or those in effect at the time - in 1940 there were 4 USD to the GBP, today there are around 1.5. After the war in around 1946-47 you could buy a surplus Spitfire IX for around £250 with a spare zero-time engine still in its crate thrown-in. Several people did, intending to use them for racing in the first post-war air races held at Lympne.

BTW, from an earlier post; Someone, somewhere will be the current 'Design Authority' in the UK (similar to Type Certificate holder in the US) for the Merlin. Not tracked this down yet either but I'm working on it. Nimbus (Cumulus nimbus floats by) 20:05, 28 March 2010 (UTC) - at least as recent as the 1980s Rolls-Royce were still supplying technical support for the Merlin and they did-so on the various engines in use by the Battle of Britain Flight as well as others. Reference to this is made in the accident report of the Mosquito RR299. —Preceding unsigned comment added by 86.112.68.160 (talk) 13:30, 22 February 2011 (UTC)

Naming

I know that the "PV" in PV12 stands for "private venture", but I also remember hearing that the "12" stood for it being a V-12. If this is accurate, maybe it should be noted in the same section. I hesitate to add this myself as I have no sources for this factoid, and I know that Rolls-Royce also produced the R11 (also a V-12) engine prior to the PV12.--173.51.110.48 (talk) 20:42, 24 May 2011 (UTC)

"Right-hand tractor" rotation

At present the article reads

"All but the Merlin 131 and 134 engines were "right-hand tractor", i.e. the propeller rotated clockwise when viewed from the rear."

A sensible amplification would be

"Except for the handed engines on the Hornet and Sea Hornet, all Merlins were "right-hand tractor"-- i.e. the propeller rotated clockwise when viewed from the rear. Kestrels were right-hand as were most American engines, but most British engines of the era were left-hand."

Unfortunately some people imagine there is some doubt about this-- so take a look at Jane's.

The section on British engines in 1938 Jane's list the following manufacturers:

Aero Engines had taken over a Weir 40-hp engine; no mention of any aircraft it powered and no indication of its rotation. No mention of the company in 1941 Jane's.

Aeronco was in liquidation. They had had a license to make Aeronca engines; no mention of any engine of their own. They're not in 1941.

Alvis engines were all left-hand; ditto in postwar Jane's with the Leonides.

Aspin shows an 80-hp engine-- no info on rotation. No mention of any aircraft using it; the 1941 edition says development suspended during the war; 1945-46 still lists Aspin, and 1949-50 does not.

Bristol is all left-hand. No mention of the Centaurus (and later editions don't give its rotation) but plenty of pics of Sea Furys and Beverlys and Ambassadors and Firebrands showing its left-handedness. Also plenty of pics of left-hand Jupiters if I'm too lazy to check the older Jane's for its rotation.

Carden/Chitton-- no info on their 32 hp engine; they're not in the 1941.

Caunter-- no info on their 100 hp engine; they're not in the 1941.

Cirrus doesn't give the Midget's rotation; the Midget isn't in 1941 Jane's. The Minor was LH; postwar editions say the Major and Bombardier were LH.

Coventry Victor-- no info on their 40 hp engine; in 1941 it has been suspended, and the 1945-46 doesn't mention any resumption.

De Havilland all LH.

Luton Anzani-- finally a known right-hand engine, a 35 hp inverted V-2. No mention of any application; they're not in the 1941.

Napier-- no info, but pics of the Short Mercury show the Rapier LH. 1941 Jane's says the Dagger is LH, and 1945-46 says the Sabre is too, if we didn't have enough pics showing them.

Pobjoy Niagara is LH; development ceased during the war, no mention of resumption in 1945-46.

Rolls Royce no info (but plenty of published pics).

Villiers Maya-- another RH engine, 120 hp; the company's not in the 1941.

No additional manufacturers (of their own engines, that is) in the 1941; the 1945-46 adds Coventry Climax but doesn't mention any engine of their own, just license-built.

In 1949-50 add Jameson with a circa-100-hp engine (just for helicopters?) and Monaco, whose production has been discontinued already.

"Kestrels were right-hand as were most American engines"-- the guys will of course object to that, and I'm not going to try to support that part. But pick an American-engined aircraft at random and I'd say odds are better than 90% it will be LH-- "most" is actually quite conservative. Tim Zukas (talk) 22:21, 24 August 2011 (UTC)

You have missed the point entirely, as I explained on your talk page: Simply adding "Jane's AWA 1938, 1941, 1945-46, 1949-50" is meaningless, and it does not comply with several Wikipedia referencing standards: using a "shotgun" approach to referencing, when the references used do not specifically point out that the Merlin was exceptional in using RH rotation is also a waste of time.

The reason your added info with the attached reference was removed is because it is entirely inadequate for a Featured Article, not because anyone imagines there is some doubt.

Find a single-definite-reference which states that the Merlin engine was unusual in that it used R-H as opposed to L-H tractor rotation NOT a whole screed of Jane's AWA with no page numbers. ◆Min✪rhist✪rian◆MTalk 01:05, 25 August 2011 (UTC)

"You have missed the point entirely"

Your point is unmissable. Your point is, the sentence "Most state names in the United States have more than six letters" must not appear in a Featured Article because we can't find anyone who specifically says that, and just going down the list of states would be a "shotgun approach".

Can anyone find where Wikipedia rules out such a citation, for Featured or Unfeatured articles? Tim Zukas (talk) 23:13, 30 August 2011 (UTC)

WP:SYNTHESIS and WP:CITEHOW are what you are looking for. Nimbus (Cumulus nimbus floats by) 23:20, 30 August 2011 (UTC)

So you think "Most state names in the United States have more than six letters" would be synthesis, and not allowed?

How about this: "On all Platonic solids, the number of faces is a multiple of four and the number of edges is a multiple of six." Probably we can't find anyone who says that in so many words; does that make it synthesis?

Fortunately, somebody at Wikipedia very presciently saw how popular such accusations would be, and clarified what is not synthesis.

http://en.wikipedia.org/wiki/Wikipedia:SYNNOT#SYNTH_is_not_unpublishably_unoriginal

http://en.wikipedia.org/wiki/Wikipedia:SYNNOT#SYNTH_is_not_obvious_II

http://en.wikipedia.org/wiki/Wikipedia:SYNNOT#SYNTH_is_not_just_any_synthesis

http://en.wikipedia.org/wiki/Wikipedia:SYNNOT#SYNTH_is_not_summary

Also, it seems "synthesis" always involves advancing a position (a thesis)-- i.e. forming an opinion from more than one source. Just using more than one source isn't automatically synthesis. Tim Zukas (talk) 21:38, 1 September 2011 (UTC)

You have, once again, completely missed the point!! Please read your citation again "Jane's AWA 1938, 1941, 1945-46, 1949-50" This does not provide any useful information whatsoever, except to convey the message that somewhere in this sequence of Jane's AWA references something might just confirm that the R-R Merlin's RH rotation was unusual amongst British aero engines. So what if it seems obvious to you? It might not be obvious to the majority of those who read the article - which is one reason why cites are used. Where on earth do you expect people to look for this information without any page numbers for reference? You added a whole series of Jane's AWA without any reference to the bibliography, nor did you add any of the cited books to the bibliography. This is a careless, "shot-gun" approach to referencing which does not conform to any Wikipedia guideline, and it is not acceptable for a Featured Article: read WP:CITEHOW to see how the system works. ◆Min✪rhist✪rian◆MTalk 19:53, 2 September 2011 (UTC)

Perhaps we're making progress. Have you abandoned your demand to "Find a single-definite-reference which states that the Merlin engine was unusual in that it used R-H as opposed to L-H tractor rotation"? Once we include page numbers (for people who can't find the engine section in Jane's) you'll be satisfied? Tim Zukas (talk) 23:08, 3 September 2011 (UTC)

You are the one who put an inadequate reference in place, with no page numbers and no indication that the information you insist on adding is actually included in the references you want to use: You also tried to add this statement "Unlike most British engines, Merlins (and Kestrels) were usually "right-hand tractor" without any references whatsoever, so please don't pretend that I and others are somehow at fault for pointing out that there is a problem with your approach.

A single definite reference which actually supplies the relevant information for the definite statement "Unlike most British engines, Merlins (and Kestrels) were usually "right-hand tractor", is infinitely better than a whole screed of references which may or may not say the same thing. I have the Jane's AWA aircraft 1945-1946 - although several British engines listed supply the direction of rotation not all entries do so eg: Armstrong Siddeley Cheetah XV, Bristol Centaurus, Hercules, Pegasus, Mercury. Nor is it obvious where one should look to find the relevant information. How do you expect people to know what to look for even with a whole swag of page numbers? It isn't quite as clear-cut as you like to make out as your list (above) also shows. ◆Min✪rhist✪rian◆MTalk 06:02, 5 September 2011 (UTC)

Ford Factory section

In the second paragraph it is stated that "Ford’s investment in machinery and the redesign..." What redesign? There's nothing else in the text explaining any redesign, apart from mentioning that the drawings had to be re-drafted to Ford's manufacturing tolerences. I let this one pass, but some explanation might be worth adding to add context to this statement. ◆Min✪rhist✪rian◆MTalk 19:29, 15 November 2011 (UTC)

Probably should read 'new drawings' or something like that. Any chance that you could add a cite for the new footnote on the Luftwaffe bombing please? I'd add it myself but I don't know where that fact came from. Cheers Nimbus (Cumulus nimbus floats by) 20:09, 15 November 2011 (UTC)

If you think that's bad you should take a look at the Packard V-1650 article - anyone reading it would think they (Packard) were instrumental in designing and developing the two-stage engines. Whilst Packard did an excellent job on producing the Merlin in large numbers I don't think they had an awful lot to do with the design of the engine. ISTR, that the Packard 'dash-number' variants were just the corresponding UK RR Mark No.s built in the US.— Preceding unsigned comment added by 80.4.57.101 (talk) 19:20, 23 December 2011 (UTC)

Packard did do a certain amount of work on redesigning and adapting the Merlin to use American manufactured components and change bolt sizes, screw thread gauges, etc to American standards, and it would seem, this needs to be clarified in that article. ◆Min✪rhist✪rian◆MTalk 20:55, 23 December 2011 (UTC)

Actually, according to the enginehistory.org site, they didn't; [1] - all the British bolt and screw sizes were replicated in the Packard Merlin. Otherwise the parts would not have been interchangeable between corresponding equivalent UK/US versions. Not much point the British having engines of their own design built for them overseas if they then need a whole set of different tools and spares to maintain them. — Preceding unsigned comment added by 80.4.57.101 (talk) 12:47, 29 December 2011 (UTC)

Applications (of the Merlin engine)

I have to say the inclusion of aircraft like the Hawker Hart* in this section is inconsistent at best (after all, the Merlin isn`t even mentioned in the Wiki article on the Hawker Hart), and downright misleading at worst. Reading this Wikipedia article will mean there are people out there who think the Hawker Hart had a Merlin engine, which, in reality it didn`t. Why would Wikipediens wish to spread disinformation, albeit unwittingly. If aircraft which only used a Merlin engine in some obscure test bed must be included, it should be in a separate list.

* I use the Hart as an example, I`m sure there are many more in that list.--JustinSmith (talk) 21:31, 6 July 2012 (UTC)

It was agreed in the aircraft engine task force discussions to include all applications for all engine types including test beds, the guideline is at Wikipedia:WikiProject Aircraft/Engines/page content. A footnote is invariably included in the applications section of aero engine articles (as it is here) to explain that it may not be the main powerplant for that aircraft type. To link the test bed aircraft in the text but not include them in the application list would be an omission. In the case of British piston engines the lists have been taken directly from Lumsden (who also includes the test aircraft). We should in theory add notes for some of the stranger, unlikely applications but we don't, the Griffon Beaufighter was disputed even though it was cited and it was eventually accepted. Nimbus (Cumulus nimbus floats by) 21:46, 6 July 2012 (UTC)

I should note that the omission of the Merlin from the Hawker Hart article is a fairly large one as it was the first aircraft to fly the engine. The difference is that article is 'B' class and this is a 'Featured Article', it has not yet been written or researched to the same level. Another editor may have addressed concerns with a recent edit but it does untidy what was a simple list and negates the purpose of the standard single covering footnote IMO. Nimbus (Cumulus nimbus floats by) 22:34, 6 July 2012 (UTC)

The addition of cites is unnecessary as the list was completely covered by the single cite No.88 (the specification section is also covered by one cite), it is overkill basically. Nimbus (Cumulus nimbus floats by) 22:38, 6 July 2012 (UTC)

Overkill? One can only kill once - but I take your point, better a .303 than a bazooka. It is, however, worthwhile to at least indicate that both the Hart and Horsley were used to test the Merlin, because some readers who don't follow the notes may be misled into thinking that the Merlin was a primary engine type. I have also added a section on engine test beds in the Hart article under variants. ◆Min✪rhist✪rian◆MTalk 22:53, 6 July 2012 (UTC)

If readers read articles from the top downwards and understood the context there would be no need for footnotes or cites in some of the lower sections, the Hart and Horsley are clearly noted well before the application section in this article. Copious citing seems to be an untidy answer to the way that articles are being read nowadays (from the bottom upwards). Nimbus (Cumulus nimbus floats by) 23:29, 6 July 2012 (UTC)

Ejector Exhausts

The article implies that the exhaust gasses left the pipes at supersonic speeds (1,300 mph). Is this really the case? I would have thought that would create shockwaves that would have needed to be managed carefully. RichardRegal (talk) 16:54, 7 July 2012 (UTC)