The engines an all these machines are JXC Hercules and are gasoline engines. International used their own engine a Black Diamond. Northart, your #2 picture is one of ours and that is a 9U D6 instead of a D5. The red combine is a Harris and is pulled by a RD6 3 lung-er. The orange one is a Case V2 and one of the last pull machines built. They were just a little late with this model as the self propelled combines came
Discuss this in the forum topic Combines Old to Modern.