I am in the process of designing and engine stand for a 4000LB semi engine. How do I find the torqe required to turn the shaft with the engine on the end?
I have been thinking about your question. You are going to be working with some seriously overhung loads with a semi-engine probably 6-feet long and 2-tons weight. If you have to ask about torque, I am getting more concerned about the structure to support that kind of load.
You are working on a piece if machinery that has a potential for some serious human injury. Not limited to but including, tipping over end for end or sideways, breaking the main support system for the rotational portion, shearing gears, tearing out stops for holding degrees of rotation.
The fact you are asking about a very simply issue of torque calculation suggests to me that you must get an Engineer to design this. It may be too little too late but I am deleting my previous assistance on the torque issue.
Generally, I will not give you the answer to your question, but I **will** guide you into discovering how to solve this yourself.