BMW LMDh prototype engine based on old DTM V8 unit

The German manufacturer has publicly confirmed that it has chosen to base the engine for the BMW M Hybrid V8 on the power unit used in the M4 DTM for two seasons before the 2019 regulations change.

The latest announcement about BMW’s LMDh program reveals that the LMDh engine, known as the P66/3, will retain the four-litre displacement of the naturally aspirated DTM unit and that it will now be directly injected.

It follows the naming of the car as the M Hybrid V8 in June without confirmation of technical details, which has accompanied the release of the first photos of the car the Rahal Letterman Lanigan Racing team will race in IMSA next season.

BMW also evaluated the in-line four-cylinder turbo engine used in DTM following a rule change for 2019 and the road-based V8 turbo engine from the M8 GTE, which raced in both IMSA and the FIA ​​World Endurance Championship.

Ulrich Schulz, head of powertrain design at BMW M Motorsport, said: “During the evaluation phase, we also looked at the P48 four-cylinder turbo engine from the [2019-spec] BMW M4 DTM and the P63 eight-cylinder turbo engine from the BMW M8 GTE.

“But potential issues with the durability of the P48 and the heavy weight of the P63 were negative considerations.”

BMW M Hybrid V8, P66/3 engine

BMW M Hybrid V8, P66/3 engine

Photo by: BMW

Schulz explained that BMW was able to use the experience of its Formula 1 entry in 2000-09 to develop the internal combustion component of the LMDh’s powertrain, which is mated to a single-brand hybrid system developed by Williams Advanced Engineering, Bosch and Xtrac.

“That saved us time and a lot of money, so it was efficient and sustainable,” he says.

“Efficiency is a critical factor for this project, as we have a very short time available between the start and the first race appearance on the Rolex 24 at Daytona in January 2023.

“It was very complex to convert the naturally aspirated P66/1 engine to a bi-turbo and then work with the electric powertrain colleagues to turn it into a hybrid powertrain.”

The new engine has already started in the M Hybrid V8 developed in collaboration with Dallara in Italy.

The car will begin testing in July at the Varano circuit, near Dallara’s headquarters.

The first phase of the test program for the M Hybrid V8 is reportedly fully planned for Europe.

The focus of the BMW LMDh program will initially be on the IMSA series with two works cars from Rahal Letterman Lanigan Racing, but the German brand has already opened the door to a possible WEC program in 2024.