so my dad has a 2004 rx8 and the engine has low compression....were gonna try the seafoam thing but eventually its gonna die....should we swap a new renisis in it or rebuild it. all the work will be done our selfs to save money....if u live in the Memphis tn area and qould like to help thatd be amazing. or if you have a rebuilt renisis sale....we will probably take motor out in 3-5 weeks. it is a 6 speed rx8 btw if that changes anything

 

If y'all are not experienced with RX8 engine swaps and want to DIY, I would recommend rebuilding the existing engine as a sort of trial run.
Then, if you think it was a success, and are confident you could do it, y'all could start planning for an eventual swap.
Just be sure to research it thoroughly, or it could become a bad experience.

 

A Renesis engine rebuild while challenging, will still be less trouble,as all the engine accessories, hoses, belts, cat, manifolds etc will fit without adjustments. A 13b swap is more involved and complicated as they are not a direct fit in your car. It is done often, so don't get me wrong, just more work and parts.