Building a wood splitter cheaply

I am interrested in building a wood splitter for my father.
Admittently I like buiding stuff but have no experience with
hydraulics. I do have an 11 horse riding lawn mower engine with
electric start. (Old Briggs)

Can I do this cheaply? Is it possible to use an old single stage
hydraulic pump from a factory or something? (If I could get it cheap).

Any ideas on how hard this would be?