Inaccurate performance data for BOB fighters in COD comparing to RL data

[TomcatViP]

Hi Bounder!,

The number of pages concerning the article (exception made of the 2 pages of adds) is only 3 pages p576 to 579. It seems for me that quoting the page was of no importance as I alrdy took great care of extracting for the reader AND in the same order what was the essential for the discussion.

That article was written at the occasion of the commemoration of 40 year of aero engine dev by RR and 50 years of History. The article is filled with 1 page add of RR. Obviously, we can understand that as it is today the article might hve been reviewed by RR !

The journalist of FLIGHT (H. F. K I N G , M . B . E) use a chronological order in his article and describe any major evolution of that engine IN THAT ORDER.

For example if he specified that 87 octane was the fuel grade in use at the time, when 100 oct fuel is introduced in an engine he noted the modification.

For example he clearly explains that if Hurri and Spits did rely on the Mk II and III, the Fulmar equipped with MkVIII could be fueled with 100 octane (with a max output power of 1080shp at T.O contrary to 1010 without - without meaning obviously with 87 ocatane ).

On point 1: yes we are talking abt 1937. It's the beginning of the article that deal chronologically with the Merlin story.

To say that the 87 oct fuel was the normal fuel used at that date I am using the quote on point 7 saying that using 100 oct fuel the Merlin XX had a 9lb boost
The date I mentioned (remark that I didn't re-use the 1942 date as in the FLIGHT article) is in perspective with the service introduction of that engine as in my own memory.

Note also that there is no mention of any use of the XX engine in the Spitfire but one on how the process of introducing that level of improvement was difficult ("These figures represent an
increase of nearly 250 h.p. over the Merlin II of identical cylinder
dimensions, and illustrate in a convincing manner the technical
progress achieved by years of 'toil, tears and sweat,' to borrow a
classical phrase from our worthy Prime Minister.")

All that makes sense to me on the base of technical grounds.

The quote made out of the rest of article are there to put the subsequent development in perpective regarding SHP and boost with the ultimate being 25lb for the post war 131/132 on the Hornet.

Hence we have two door in the Merlin history acording to the article : one in 1937 for introduction of 87 octane (confirmed in 1940 with the mention made of the Fulmar using a special engine) and the other in 1941 (42 in Fligt article) for possibility of 100 octane usage in the mkXX.

After that date it's upon the reader to decide witch fuel was in use since the article does not mention any switch (witch I found interesting despite all the other details of the engine modifications) but it's another story

Note also that in 1954, the merlin with 150000 units produced (all manufacturer included) represented more than 80% of all engines build by RR at the time (185000)

Source : http://www.flightglobal.com/pdfarchi...0-%201286.html