1921 Napier 'Blue Bird' Homage

1921 Napier 'Blue Bird' Homage

Constructed on a 1921 Napier chassis, it is powered by a 24-litre 12-cylinder Napier Lion aero engine, a power unit with the unique distinction of having held the air, land, and water speed records. The Lion engine had been bought directly from Napier by Jacobs' grandfather and a friend who worked in the company's drawing office. It is a 'marinised' version of the Lion engine and had been despatched to Vosper & Company in Portsmouth in 1930. The two friends had intended to install the Lion in a car but the project never bore fruit.

Founded as precision engineers in 1808, the Napier company diversified into motor car manufacture in 1900, encouraged by the pioneering Australian sporting motorist and entrepreneur, Selwyn Francis Edge. During WWI, the firm was contracted to build Sunbeam and Royal Aircraft Factory aero engines before moving on to produce its own: the Lion. The latter was designed by Arthur John Rowledge, later to contribute to the Merlin engine's gestation while at Roll-Royce, and first ran in 1917. Eschewing the established inline and rotary/radial engine layouts, Rowledge opted for a so-called 'broad arrow' or 'W12' design, arranging the 12 cylinders in three banks of four on a common crankcase. Boasting twin overhead camshafts and four valves per cylinder, this state-of-the-art power unit produced 450bhp initially, making the Lion the most powerful aero engine of its day.

The first person to recognise the Lion's potential as the power unit for a land-speed record-breaker was Malcolm Campbell, who installed one in his 'Blue Bird' in 1927. Campbell was followed by Henry Segrave, who also used one to break the water speed record, and John Cobb. In 1947, Cobb took the world record in his twin-Lion-engined Railton Mobil Special at 394.19mph, becoming the first person to exceed 400mph on land in the process.

Lorne Jacobs had known about the family's Lion engine since childhood and had developed a fascination for the Napier-powered record breakers driven by Campbell, Cobb, and Segrave. He decided that the engine should be used to construct an 'homage' to the first such car: Campbell's 'Blue Bird' of 1927. This would be a colossal undertaking for the average mortal, but Lorne Jacobs already had 35 of working on Bentleys and Bugattis under his belt, as well as the construction of various big 'specials', so was undaunted by this new challenge.

His first task was to un-seize the engine, which was then fully rebuilt with new lighter pistons (commissioned from the USA), new specially made con-rods, and new bearings throughout. With re-profiled camshafts and an increased compression ratio (from the original 5.8:1) the engine now achieves 3,200rpm, some 1,000 revs more than standard, and is estimated to produce getting on for 700 horsepower. Maximum torque is estimated at circa 1,800lb/ft (for comparison: the Bugatti Chiron has a mere 1,180lb/ft at its disposal). This proved too much for the first gearbox employed - from an Austin 20hp - so a Bentley D-type 'box is used now, suitably up-rated with a modern gear set. The rest of the running gear is Vintage-period, comprising a Delage front axle, Minerva front brakes, and a Bentley 6 1/2-litre rear axle and brakes. The brakes are hydraulically operated and the car rolls on 19" wheels. There are two alternative exhaust systems: stub exhausts for racing and a 'Brooklands' system for the road.

The length of the Napier chassis dictated the size of the body, which is considerably shorter than that of Campbell's 'Blue Bird'. Using original 'Blue Bird' plans and contemporary photographs for guidance, Lorne hand-formed the seven-piece aluminium body using an English Wheel to achieve the compound curves. Contrasting with the Spartan cockpit of the original 'Blue Bird', the Jacobs car has a full complement of instruments and is a two-seater rather than a monoposto like the record-breaker. The Napier chassis frame has Invicta spring hangers to enable external mounted leaf springs.

In its article on the Jacobs Napier published in the August 2017 edition, Octane reported that the car could smoke its tyres at 80mph. The 0-60mph dash had been achieved in approximately 6 seconds (in 3rd gear!) 'resulting in the need for new tyres', while the owner reported that on the current gearing the car will 'accelerate in a relentlessly linear fashion to around 120mph'.

In 1924 at Pendine Sands, Malcolm Campbell, driving the 350hp V12 Sunbeam, broke the land speed record for the first time.

Descriptions & pictures by bonhams & drive-my & classiccarcuration