Here’s the timing chain replacement process on the N12/N16 engines. They maybe be slow engines but they are super solid from my experience

These non turbo engines are equipped in the following models
R55 Mini Cooper Clubman
R56 Mini Cooper Hardtop
R57 Mini Cooper Convertible
R58 Mini Cooper Coupé
R59 Mini Cooper Roadster
R60 Mini Cooper Countyman
R61 Mini Cooper Paceman


For reference the procedure is identical to the N18 Timing Chain replacement. Same torque specs and all, just different valve cover and intake and exhaust setups

Obviously half of the engine is different but procedures are all the same concept