You should ask more detailed what you need: gasoline engine or diesel engine, two stroke engine or four stroke engine, steam engine, ...
Here some examples (which I posted) in the past.
https://grabcad.com/library/two-cylinder-engine-1
https://grabcad.com/library/twin-cylinder_steam_engine-dyn_sim-1
https://grabcad.com/library/twin-cylinder_steam_engine-1
https://grabcad.com/library/steam-engine-jls-13-2-1
https://grabcad.com/library/vertical-twin-steam-engine-with-reverse-gear-dynamic-simulation-1
And if you search here you will surely find a lot more.
Greetings