This engine is in a Ford CL65 Skid Steer. Just figured out that the engine in this unit is likely not the Shibaura U1004 that it originally came with. So what is it? Obviously a 4 cyl diesel. There's a casting mark on the left side of the block that says "S2". There's a serial number stamped into the right side of the block "P11061". Beyond that I can't really see any other identifying marks albeit it's a bit tight in there and hard to see.
Link to albumSkid Steer Engine ID - Album on Imgur
Link to albumSkid Steer Engine ID - Album on Imgur