Originally Posted by
Mon the fish
Loads of people have looked at blowing Coopers, just isn't worth it. Gearbox can't take the strain, compression ratios are different, the Cooper S has a lot of upgraded engine internals, etc etc. If you really want to do it, get hold of a Cooper S engine and gearbox from a breakers, but even then it still won't be worth it.
Sorry to disappoint you! I drove the Janspeed 140bhp Cooper years ago, thats the limit of what you can do before the gearbox goes. Gasflowed head, manifold, intake and new back box. Quick car, sounded brilliant.