[Jeff Chambers]

As a shop owner, a pretty well versed engineer, and having been involved in similar cases as an expert witness, he's got an uphill battle if he intends to sue. There's just too many variables involved to be able to show fault without reasonable doubt.

Sorry to say, but he's probably going to have to suck it up and take the losses. In the performance world, there are generally no warranties expressed or implied. Now you say his motor has a warranty (in writing?), undoubtably a warranty against defects in workmanship by the shop that built the engine. Since its 2000 miles down the road and others have had ample opportunity at the motor (i.e. Jiffy Lube), a court of law will likely dismiss the shop's warranty without prejudice. BTW: Your openly public admission of having raced him on the street is cause enough alone to have the case dismissed.