While there were a fair few applications for the Liberty engine the vast majority would have been used in aircraft in the US.

The only tank that used them in the US was the WW1 era Mark VIII ‘Liberty’ tank; only one hundred of these were built in the US with liberty engines. These weren’t used much and, after years in storage, were eventually exported to Canada in 1940 for training.

The British used derivatives of the Liberty engine in some tanks during WW2 but I believe these Nuffield-built engines used a different design of piston. The major British tank application being the Crusader (Cruiser, Mark VI or A15) built between 1940 and 1943 and mainly used in the deserts of North Africa; I believe the desert sand and dust played havoc with the piston ring grooves (despite the air filters) requiring a more resilient design of piston.