Quote:
Originally Posted by Excaliber
I was referring to the 427 GT-40's.
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Yes, most all the GT40 big block cars did not run webers (I say most all, because the J car Ken Miles died in was specially fitted with webers), but that is really a separate animal from what Shelby American was doing. I can't devote the time to this post to expand on/substantiate all the conclusions I've drawn from alot of research, but a major factor does appear to essentially coincide with zrayr's statement about not needing more power and simplicity.
All evidence indicates Ken Miles/SA were always interested on running webers on all their race engines, but Ford's influence over SA's activities became overwhelming once they received the contract for the GT40 development and Ford's engineers were approaching things from a different angle: given the competition and their expected improvements, engineers back calculated required HP to achieve desired lap times and they were able to reach the targets with their slightly modified NASCAR type 1x4 engines during the initial MKII GT40 development. I spoke with Gus Scussel about this, who was one of the Ford guys in charge of the GT40 big block engine development and he said they didn't even really consider webers, as they were able to get the desired performance with parts they were already familiar with and he was interested in simplicity. They ran the 1x4 Holley on the MKII cars in '65 and '66.
Based on numerous inputs, other potential factors for them not going with webers on the big block engines include: Mr. Ford supposedly didn't want Italian parts used on his cars after the lost deal with Ferrari (especially something as prominent as the carburetors), he wanted the cars to most closely represent what an average consumer could purchase off the showroom floor in their Galaxie, they were experiencing durability problems with the big block and didn't need an induction that would only exacerbate the problem, the big webers were in short supply, and also the cost differential. The durability aspect was not insignificant - consider a dry sump system was developed out of necessity for the 427 engine after durability problems when using the Aviaid pan, yet they never felt the need for the same thing on the 289. Ford even set relatively low rpm limits during Lemans for the big block engines, I recall it was something like 6300 rpm for most of the race with short excursions allowed upon certain conditions.
As the competition became tougher and target lap times lowered, Ford pushed the development of the 427 engine and, probably also from NASCAR demands, the result was the tunnel port for '67 Lemans. Ford engineers found they were again able to achieve their targets with known components, by just going with 2x4 Holleys. Much like today's "customer engine" deals in F1, Indy cars and the like, Ford prohibited SA personnel from substantially disassembling or extensively modifying the GT40 engines as they arrived from Ford. Ex-SA employee Steele Therkleson remembers showing Ford engineers how SA detail internally prepped their engines so it could be done at Ford from then on. Ken Miles, however, was always trying to put Shelby American's influence into the cars and according to reports he pushed Ford to have the one engine in the prototype J car outfitted with webers for evaluation and possible fielding in races. When Ken died in that car so did all plans for use of the webers on the big block. Even if Ken would have been successful in getting the Ford engineers to seriously consider using webers, by that time fuel injection was all the rage and if the engineers pulled the trigger on IR there is a high probability they would have just gone FI. This was actually manifested with the FI on the 3 valve Calliope engine which Ford had developed by '68 for the GT40 as a potential successor to the FE (by the time that engine was finished, however, Ford had already pulled support of the Lemans effort).