I know they don't replace much so my main question is.... is it worth the money to rebuild a 13b? Or should I just replace EVERYTHING! What part(s) are they actually "rebuilding". I know it may sound dumb but I had to ask. Thanks.

 

To replace everything, making everything brand new, is somewhere in the neighborhood of $6000+. Basically, the parts that are not within spec, are replaced in a normal rebuild.

 

From what I know, a rebuild is technically just replacing the seals, (water, oil, apex, etc..) But during the process the rebuilder would make sure everything else is within spec. i.e., rotor housings aren't grooved, no pitting, etc. And if any part is not within spec, it gets replaced as well.

My engine is curently being replaced at KDR, and the owner of the shop, Dave, told me that most of the time the rotor housings are lapped, especially on higher mileage engines, so it usually ends up being cheaper to just buy a reman from mazda, which is what I did.