OK...for those interested in the development of the Jaguar V8 engines (beginning with the 4.0 litre V8 for the XK8 and moving on the the 4.2 litre and 5 litre versions used in the XK [X150])), and especially for those who think that these engines were developed by Ford, there are a number of authoritative sources (as opposed to rumour or popular opinion). One of the best of these is Philip Porter's XK8, the Authorised Biography (Bay View Books Ltd., Bideford, Devon, 1996, especially chapter 5, "The AJ-V8 Engine"). You will note the publication date which is also the year of introduction of this engine - the predecessor of the 4.2 and 5.0 litre engines. So the information regarding the development of the V8 engine is immediate, not seen through the mists of time - and the respective roles of Ford and Jaguar in the development of the whole new car (the XK8) and its engine is presented in detail - including the roles of Jaguar's engineers, especially Dave Szczupak who managed the entire engine programme - he had been with Jagur since 1985 - and he is quoted as saying: "The (development of the) V8 engine started in the late eighties". Trevor Crisp, Powertrain Group Chief Engineeer (with Jaguar since 1954 - yes, 1954): "The AJ-V8 engine is only the fourth *totally new* concept in Jaguar's history." (both on p.65)...on p 66, Szczupak again: "This all started before Ford's ownership. The take-over didn't change the design, but it changed the way we managed the programme, particularly when the prospect of building the engine at Ford's Bridgend plant came along....". Dave Szczupak further says: "With Ford having a wide range of engines...there was a great deal of dialogue and healthy debate *as to whether Jaguar should continue to design this new engine*....why couldn't we modify a Ford engine?...having understood who our true competitors were, Ford realised that *we had to have a bespoke engine*..." (p.66)
OK so far? Now about Bridgend, Szczupack continues: "So the great debate then was whether the engine was going to be built at (Jaguar's) Radford or at (Ford's) Bridgend. Radford need a lot of refurbishment. Bridgend had an *empty building of ideal size, and the superb infrastructure of a completely modern, new facility*...We knew at Jaguar that we could not build the engine in the old Radford plant...the infrastructure available at Bridgend - as well as the sheer economics of this solution - made the decision obvious". (p.67).

There is a great deal of detailed information about every aspect of the V8 engine design, pages of it, cited in the words of the engineers themselves, and in Porter's overview: "The foundation of any engine, of course, is the block design, and guided by finite analysis, *the Jaguar engineers have striven to combine light weight with structural stiffness....*. Note - "the Jaguar engineers" - we are well beyond the idea of a Ford design...and regarding the (eventually) disastrous Nikasil use for the cylinder bores (never used in a Ford engine, by the way - but used also by BMW with the same sad result): "Rather than using conventional iron liners, the bores are plated with nikel-silicon carbide (Nikasil)....Once again *Jaguar (NOT FORD) has followed Formula I practice in adopting this technique...the Nikasil plating of the aluminium cylinder bores is a totally new technology for Jaguar* and indeed *BMW is the only volume manufacturer using it*." (p.72)...and "the precision cooling system has been patented by Jaguar" (NOT Ford); (p.72)..."A number of key suppliers were involved by Jaguar very early on...Cosworth helped with the cylinder head design in terms of casting technology. Kolbenschmidt, the block supplier, was also involved early on..." (p73). No mention of Ford at all among the suppliers. Further on: "While Trevor Crisp's role has been to oversee the whole powertrain, Dave Szczupak's has been to mastermind the AJ-V8 engine." (p.74). Page after page of authoritative, detailed information about engine development and production when Ford owned Jaguar, and none of it supports in any way the notion that Jaguar used Ford engines. The V6 later used in the S-Type and the X-Type did use the Ford Duratec block - but the top of the engine was a Jaguar design and while there are certain interchangeable parts, again the engineering was by Jaguar. Current engines, such as the 3.0 litre supercharged V6 and and the 5 litre V8 as used in the F-Type are Jaguar designs - and then there is the turbocharged 4 cylinder that puts out almost 300 hp....
Still not convinced? Is your membership in the Flat Earth Society paid for this year? (I know...but I can't help it...).