Engines that can run in either directions.

I know that steam engines that can run in either directions. I thought that gas and diesel engines can't run in either directions until I found out that a passenger railcar built in 1910s had a gas engine that can run in either directions by moving the camshaft. From searching the Internet, I found out that some two-stroke engines can run in either directions but not 4-stroke engines. Marine two-stroke engines can run in either directions. The railcar must have a two-stroke engine. Search the Internet for McKeen Motor Car Company.