In contrast to various speculations before the official reveal which guessed the cubic capacity to be slightly more, Royal Enfield unveiled their next generation twin-cylinder engine at their brand new technology centre in Leicestershire, England. This new Royal Enfield 648cc, air-cooled parallel twin motor will power the newest generation of thumpers.
According to RE, the core idea behind the development of the new motor was to develop a platform that would carry their legacy and character into a modern context. They say the new motor has been designed to offer the right balance between power, torque, and usability to ensure a smooth and unintimidating riding experience. The new motor is said to offer a broad spread of torque which should make the motorcycle it powers easy to ride without frequently shifting gears.
The new Royal Enfield 648cc platform is a 4 stroke, single overhead cam, air-cooled, parallel twin cylinder engine developed by Royal Enfield’s UK Technology Centre and Chennai teams. Engineered to be able to accelerate and deliver higher power and torque at lower RPMs, this new engine has an output capability of 47bhp and 52Nm torque. Classically styled, the engine has been designed to achieve a high level of modern refinement.
It maintains an under-stressed 9.5:1 compression ratio and is fed fuel by a modern injection system. The focus of the development was on giving adequate torque, spread broadly throughout the rev range so that riders can tap into it instantly at any time without the need for excessive shifting. Making this possible are a number of elements, starting in the very depths of the engine where there is a single-piece forged crankshaft (a first for Royal Enfield) which ensures strength and the ability to handle the twin’s torque. This crankshaft uses a 270-degree firing order, which gives a high degree of character to the engine’s power delivery. Also, thanks to the use of a balancer shaft, unwelcome vibrations should be eliminated.
The new Royal Enfield 648cc platform uses ambient air-flow combined with engine oil to keep engine temperature at an optimal level rather than a radiator, fan, hoses, and other components. This keeps the motor clean looking and essentially pure, like the experience it aims to provide. Just as relevant as the engine’s individuality, is its sound. The characteristic ‘thump’ of Royal Enfield’s singles is cherished by legions of enthusiasts, and great lengths were taken to ensure that the new 650 twin gives an equally compelling soundtrack. Hours were spent tweaking every contributing variable to engine sound, resulting in twin silencers that rumble with just the right tone. The entire platform, including the engine and chassis have undergone rigorous testing during the development programme. It has been subjected to lab and bench tests, in addition to being tested on proving grounds, race tracks and public roads.
4 stroke, 270 degree crank, single overhead cam, air-oil cooled, 648cc parallel twin
47bhp @ 7100rpm
52Nm @ 4000rpm
Bore x Stroke
78mm x 67.8mm
Digital spark ignition – TCI