I recently bought a 79 450 sl that I bought without hearing it run....we put in a ring gear because the ring gear has a bad section. When we got it started, it sounded really bad, with what sounded like a lower end knock and alot of valvetrain noise....sound ing like a diesel. We took it apart thinking it was a spun bearing. What we found were pieces of the timing chain guides...the plastic ones in the bottom of the pan. Upon getting the front cover off, when the chain is in a certain position the chain gets slack and allows the center gear to move back and forth producing the lower end knock noise....Help!! what do I have here....what do I need to replace, could the valves be bent? The chain is intact...what should I look for?
Any help would be appreciated...thanks John.....PS to put things in perspective...this is what I bought my wife for her 49th B-day, and I don't have it running yet!