Searching for ancestors of Joseph Espey/Espy

I am hoping to find some information on my great great grandfather Joseph Espey/Espy born 1816 in Ireland (County Tyrone).  He arrived in Canada out of Belfast approximately 1848 although I have been unable to find a ships record for this.  I have heard his fathers name was James but am unsure how accurate this information is.  He died 20 Feb 1879 and is buried in York County Ontario Canada.  I keep hitting  brick walls with this.  If anyone has any information I would appreciate it.