Commission Sportive Internationale announced in 1952 that 2.5L naturally aspirated engines would be a part of Formula One regulation starting 1954. Walter Hassan and especially Harry Mundy having their roots deeply in the racing field, started discussions and preliminary designs of a 2.5L 8 Cylinder GP engine in 1952 without a formal directive from the father and son Pelham Lees. Because this project was a pure racing engine from the beginning, which was in stark contrast to the corporate product history up to FWA, the engine was named FPE for 'F'ire 'P'ump 'E'ngine ('E'ight according to another lore) by the playful minds of Hassan and Mundy.
After the corporate blessing was given to the project with the name 'Godiva', this DOHC 90 degree steel crossplane crank V8 engine was built in 1954 for a F1 Kieft with the intention to use the fuel injection system made by Skinners Union (SU).
However, this fuel injection system, being designed for aeroplane engines, was found not having the means to enrich the mixture for acceleration, which is not suitable for automobile use. FPE initially showed 240 bhp using Weber carburettors, but the press at the time reported the rumoured fuel-injected Mercedes 2.5L GP engine is quoted as producing more than 300 bhp, and a corporate decision was made not to release FPE to Kieft in light of the lack of proper fuel injection, leaving the Kieft F1 project, as well as other prospective users, HWM and Connaught, high and dry.
There were reports to the effect that the engine was not run because of fears about the rumoured power of other 2.5L GP engines, but shortly after, John Cooper brought a race-winning, works Maserati F1 engine he had on loan into Coventry Climax, where it produced 225 bhp running on the same dynamometer upon which the FPE had made 264 bhp after some development.
Ultimately, development on the engine was abandoned in favour of focusing on the FPF engine, which was already proven competitive in 1.5L form with side-draft Weber carburetors in the F2 races, and the entire stock of parts were sold to Andrew Getley in the mid-1960s. When the Formula One regulation changed to 3 Litres for 1966, Mr. Getley permitted Paul Emery to rebuild one FPE to 3 Litre format, and fit it to a one-off Shannon steel monocoque chassis to make the Shannon F1 car named SH1 driven by Trevor Taylor at 1966 British Grand Prix. Bored out to 3 Litres and Tecalemit Jackson fuel injection installed, this Emery-built FPE produced 312 bhp on the dynamometer at Chrysler's Kew facility.
Remnants of other FPE parts were much later found by the then-owner of 1954 Kieft F1 chassis, Gordon and Martyn Chapman, in an air-raid cellar in the abandoned building which used to belong to Bill Lacey (of Power Engines Ltd., a Coventry Climax specialist) near the main entrance of Silverstone Circuit, including 3 blocks, 2 cranks, 16 cylinder heads, 20-some cam covers (carriers?), two cardboxes full of timing gears and camshafts, which all belonged to "Doc Murfield" who had purchased the parts from Andrew Getley in 1968-69 and had entrusted them to Bill Lacey.
These parts were assembled into two engines under the ownership of Gordon Chapman and then under Bill Morris, who bought the engine parts and the Kieft chassis after Gordon Chapman's death. One engine was sold by Chapman to the then-owner of Shannon SH1, and this FPE is said to be in Austria together with Shannon SH1 Another using two of the later type twin spark plug heads in the stock, was run in the original 1954 Kieft-Climax V8 Grand Prix chassis with downdraft Weber 40IDF carburetors when they were finally mated and the construction finished on September 21, 2002 at VSCC Silverstone Meeting, and this car was campaigned in VSCC events for the next 10 years.
Four sets of period-correct Weber 40DCNL carburetors were installed on the FPE during the 10 years, and the car, one spare chassis, and the FPE parts were sold in a lot at Bonhams Chichester auction on September 15, 2012 for £185,000.