Ive got a 2002 base model mini and ive got two bent valves in the head. I found a guy sellin a head at a good price, but its off a supercharged model. Will this work, or will it need to be retuned?

 

i do believe it will work, it will just be stronger. best bet to have someone esle chime in

 

Have you brought the head to a machine shop....
You might be surprisd how cheap changing the valves are if it is in good shape....

 

Im going to take it in this afternoon for an assessment and possibly a quote

 

Base Coopers use a non sodium filled valve, which will burn and cause large compression leaks through the exhaust.

The S valves are sodium filled, and will resist burning far superior to the base Cooper valves. other than the valves and the different heat range spark plugs, you'll be able to bolt the S head right onto the base Cooper block.

Before you take the job on you'll want some parts, resources on hand; I would recommend a Bentley manual, the head bolts are single use bolts, I would replace the head gasket as well as the thermostat. Other than that you'll want to do an oil change, coolant flush, the basics.

Nick
Detroit Tuned

 

If I'm not mistaken, the compression ratio on the "S" engine is lower than the base model. The bore & stroke are the same to the change is either the pistons, the head, or both.

But if it's in the head, the lower ratio will cause you to loose power in your non-S engine.

 

You are correct in the S engines having lower compression than the NA Cooper engines, the compression difference is in the piston heads, you shouldn't have an issue bolting an S head onto a Cooper.

 

nkfry,

Thanks for the clarification. I've not torn one down to look at the differences but if the difference is in the shape of the piston then the head should bolt right on.

So it looks like that option remains if the rebuild quote is too high.