This is the 640PS hybrid V8 engine powering BMW’s LMDh racer

Both four-cylinder and other V8 engines were considered, the latter from the M8 GTE, but durability worries and excess weight put paid to those ideas. The P66/3 which BMW M has arrived at is a 4.0-litre twin-turbo V8 good for around 640PS (471kW) and revs up to 8,2000rpm. In the M4 DTM, it was naturally aspirated and unhybridised, which means the unit needed some development to make it suitable for the extra components. It’s also been modified to incorporate direct injection.

An interim P66/2 development engine was created to develop the turbocharging system, with a focus on heat management and durability. This test bench engine ran a number of simulations including virtual track runs. The P66/3 final race engine incorporates external ancillary requirements, including how its mounted, exhaust routing, oil tank positioning and high-voltage wiring.

For the hybrid system, or rather its integration with the internal combustion engine, expertise was brought in from BMW’s Formula E project. As of the end of June, both the hybrid system and petrol engine are in the car and ready to go. With the first fire-up done, it’ll be out testing on-track by the end of July. We’re excited to see BMW return to the top level of endurance racing, alongside rivals old and new.