With plans to shift its entire vehicle lineup to battery electric offerings by the end of the decade, it’s clear that Cadillac has wholeheartedly embraced the battery electric vehicle movement. However, that doesn’t mean the luxury marque has completely turned its back on gasoline-powered engines, particularly in its racing efforts. In fact, good old racing fuel took Cadillac Racing back to the podium at the 24 Hours of Le Mans earlier this year, thanks to the LMC55.R V8 engine under the hood of its V-Series.R race cars. Now, we’re taking a look at the powerhouse responsible for the feat.
Cadillac Society recently obtained photos of the eight-cylinder engine in question, along with details regarding its design and development. The LMC55.R moniker isn’t as mysterious as it sounds, as it stands for Le Mans Cadillac. The engine was built at the GM Racing and Performance Center in Pontiac, Michigan, in conjunction with Roush Advanced Composites. It’s currently the only naturally aspirated hybrid engine in the WEC Hypercar class and IMSA GTP division, making it a rarity on the endurance racing circuit.
As for the guts, the LMC55.R V8 engine boasts 5.5 liter displacement, dual overhead cams, 32 valves and a 90-degree cylinder layout. “Advanced materials and manufacturing techniques” make it possible to mount the engine as a structural component inside the Cadillac V-Series.R race car. It maxes out at 670 horsepower, while its torque output depends on which racing series it is being run in. The engine is paired with a 50kW electric motor, and power is relayed to the driving wheels by way of the Xtrac P1359 seven-speed automatic transmission.
According to one of the members of the GM Motorsports Competition Group, the LMC55.R engine was designed with a promise to “deliver a distinctive sound that would make it easily identifiable as it roared around the track.”
Want the latest on all things Cadillac? Subscribe to Cadillac Society for more Cadillac racing news around-the-clock Cadillac news coverage. We also invite you to join the latest discussions in our Cadillac forums and Cadillac Racing forum.
One of four new colors for the 2025 model year.
And it now represents the best value in its segment.
A curious sighting from a video of the Cadillac design studio.