[Unobtanium-inc]

Please note that PayPal will NOT refund your payment, offer protection, etc. on something based on the condition. If you click "item was not as described" in your complaint, your claim goes into a paypal black hole with no way out. The minute you escalate to a full claim you get an email from them saying they do not arbitrate condition. The ONLY way paypal protects you is in the case that you don't receive the item at all.

Sadly, there's really nothing you can do short of showing up at the guy's house with the engine and appealing to his humanity. Save the money you would have spent shipping it back and use it toward this engine, or toward buying a better example.