when should the timing chain be changed in our cars? im getting a new engine anyway so im having it done but my frien might needlessly do his so im trying to save him some cash.

 

Any time you plan on getting into that neck of the woods it would be wise. If you want miles then I would shoot from the hip and say 100k. They stretch plain and simple. Yes some are built better than others but they eventually stretch. Unless you have timing gear set. If you have knocksensors then you can kiss that idea goodbye.

Timing chain sets are very inexpensive, especially if you go stock. You can get a decent double roller set for around $25 from summit.

 

Correct. Unless it's chattering it's not worth the hassle. Of course if you're already there.......