BMW recently unveiled the M Hybrid V8 LMDh racer, and while people were expecting a new V8 at the heart of the BMW's LMDh (Le Mans Daytona Hybrid) endurance racecar, the company has revealed that they will use an older V8 engine that was designed for BMW's 2017 - 2018 M4 DTM (Deutsche Tourenwagen Masters) car.
BMW had many ideas, one of which was using the twin-turbo 4.0-litre V8 used in the BMW M8 GTE, but that unit was too heavy. They even considered the turbocharged four-cylinder engine used in the 2019 M4 DTM car but didn't think it would last the duration of the endurance races. In the end, BMW settled on repurposing an older naturally aspirated V8 engine for this job, and there were multiple reasons for it. One of the most important reasons was that it was the engine that "most closely corresponded to the regulatory requirements after conversion to a hybrid turbo engine".
Why not make a completely new engine from scratch then? Well, doing so would've costed BMW a lot more money, and to this thought, Ulrich Schulz, Head of Drivetrain Design at BMW M Motorsport said "Returning to the drawing board to design a completely new engine and building it at great cost was not an option".
BMW ended up making several changes to the engine. First of which was adding twin-turbos to the NA V8 mill and adjusting the crank drive, followed by adjusting it to the LMDh car's Dallara chassis, recasting the cylinder heads and block, and fully rebuilding the injection system. Then, using the help from its former Formula E team, BMW integrated the electric motor, invertor and battery, making it a hybrid powerunit.
The result was a regulated 631 bhp & 650 Nm torque (standard for LMDh class) from a 4.0-litre twin-turbo V8, which can rev up to 8,200 rpm! BMW has confirmed that the testing of the racecar will begin "immediately", and the car will go on to race in the 2023 season of IMSA WeatherTech SportsCar Championship.
