Bentley Mulliner Bacalar W12 Engine

The most advanced 12-cylinder W12 engine in the world has completed its assembly and production testing for the first Bentley Mulliner Bacalar.

Bentley Mulliner’s Bacalar have made a phenomenal return and it is sporting a newly improved version of Bentley’s powerful 6.0-litre, W12 TSI engine. The unique W-configuration means that the engine is 24 percent shorter than an equivalent V12, benefitting packaging and maximizing usable cabin space.

Initially introduced in 2003, the present twin-turbocharger W12 engine however has been upgraded with an increase of up to 27 percent in power, 38 percent in torque and a reduction of 28 percent in emissions. Now it is able to produce 659 PS of power and a torque of 900 Nm.

A grueling process of over 6.5 hours is taken by a team of 45 craftspeople to carefully manufacture each one of the W12 engines.

These enhancements were achieved through the betterment of the crankcase, improvements in the oil and cooling systems, twin-scroll turbocharging technology and more effective injection and combustion processes.

The engine gets a crankcase that is 30 percent stronger than its predecessor, while the cylinder surfaces were coated to reduce friction and improve corrosion resistance. It is designed to bring the cylinder heads up to optimum operating temperature for best engine performance and low emissions.

In order to reduce emissions along with optimizing power and torque delivery, the W12 engine combines high-pressure direct fuel injection with low-pressure port injection. The exhaust assemblies for the three front and three rear cylinders are separated from one another which then feed the twin-scroll impellers.

Plus, the turbocharger housing is welded directly to the exhaust manifolds and features integrated speed sensors, allowing the engine to monitor turbo performance for maximum efficiency. Along with Bentley’s Variable Displacement system it will run in gears three to eight, below 3,000 rpm and up to 300 Nm of torque output.

On another note, the Bacalar W12 engine has been put through three types of highly sophisticated test regime of over an hour via three specialist diagnostic machines. In which they are part of Bentley’s exceptional quality control processes.

The production stage known as a ‘short engine’ is the first test that it goes through. It is to check for any leakage and can only be examined after the engine has been assembled. The leakage test is conducted by pressurizing each of the systems, for fuel, oil and water individually.

‘Cold test’ is the second and most advanced stage. The engine is loaded on to a test bed plate and connections are made to the engine loom and all engine systems, whilst a large electric motor couples to the engine via the crankshaft which allows the test bed to collect data from a suite of sensors.

In order to gather cylinder-specific data, ‘Cold Test’ is carried out before the exhaust manifolds, turbochargers and other ancillaries are fitted. The ‘Cold Test’ can confirm the engine timing is accurate and therefore achieving the best possible combustion cycle.

Third and final test is the ‘Hot Test’. It checks the complete engine assembly once these parts are installed, and simulates real world usage in the vehicle. As the engine undergoes hot testing, the coolant and fuel system are pressurized with air and nitrogen respectively for a final check before introducing the necessary fluids.

Since the installation of the three test beds in 2002, over 100,000 W12 engines have been handcrafted at the home of Bentley Motors in Crewe.