BMW’s 640bhp M Hybrid V8 endurance racer uses an old DTM engine

BMW’s new LMDh racer will use a V8, this much you know. What you might not know is that it’s not a new eight-cylinder, but rather an old one originally designed for BMW’s DTM car.

BMW M Motorsport engine boss Ulrich Schulz said the reason the team has enlisted the old boot back into service was time, and money. “Returning to the drawing board to design a completely new engine and building it at great cost was not an option,” BMW said.

So, the team looked at which BMW engine could be repurposed to win lots of shiny things next year in the WeatherTech SportsCar Championship. Unsurprisingly, they considered the twin-turbo 4.0-litre V8 used in BMW’s sensibly-sized M8 GTE but found it to be too heavy.

Surprisingly, they also looked at redeploying the turbocharged four-cylinder used in the 2019 M4 DTM car but found issues with durability. Goldilocks arrived in the shape of the old naturally aspirated V8 used in the 2017 and 2018 DTM campaigns.

Why? It acts as load bearing member and was the engine that “most closely corresponded to the regulatory requirements after conversion to a hybrid turbo engine”. Indeed, the first step required bolting on a pair of turbos to the nat-asp V8 and adjusting the crank drive.

Then came testing for durability, cooling and more power, while the final step – creating the ‘P66/3’ version – involved adjusting it to the LMDh car’s Dallara chassis, checking the exhaust, oil tank, cabling and “integration of the high-voltage environment” (DANGER! DANGER!).

BMW even recast the cylinder heads and block, fully rebuilt the injection system and integrated the e-motor, invertor and battery using help from its former Formula E team. It even referenced it’s time in motorsport’s most famous category. “It is a huge plus that we were able to make use of exiting materials such as steel and aluminium from BMW’s time in Formula One for the basis of the engine,” Schulz said.

The result is a 640bhp 4.0-litre that redlines to 8,200rpm. After a ‘rollout’ in Italy, “the intensive test phase begins immediately”. Watch this space.