If a porting job is done bad . What are the side effects? Like can the engine still run if it has a bad port just wont have the horse power numbers it should have? Would it have low compression? Thank you for your help.

 

"bad" is a very subjective term. It depends on how bad it is.... Basically, poor porting will not give you as much of a power gain as you should see at best, and will probably lead to you blowing an engine quickly if it's really bad.