Congrat's on your JCW!  If you send me the last 7 digits of the vin number, I can send you a copy of the build sheet for your car. (kens at minimania.com)

You should be fine with the Cooper S head if you can't find a JCW head, the only difference is some very minor porting.  

Cheers, 
Ken

As was mentioned, you should refresh the supercharger oil when you have the engine disassembled.

Double check that your car has the full JCW kit - the head is specific to JCWs and finding a new one will be a pain.  It would also be good if you managed to get the original JCW parts to go along with it, for example the s/c pulley, larger injectors and suspension (springs specifically) assuming it came with the JCW sports suspension. The springs were NOT part of the  JCW kit and were an option on top of the  JCW. They are red. Did you also get the JCW brakes?  again this was a stand alone package and featured larger red front calipers/disks.  Unless you got a JCW intake as spares, you can assume it was NOT a 210 HP JCW kit on your car. JCW in general are no longer available from the dealer and are desirable. Tracking them all down will be a pain so keep an eye out for used parts. Do join NAM as there are many knowledgeable people out there  and most issues have well documented DIYs. 

Since it looks like you will be tearing apart the engine bay, its worth:changing the s/c oil,installing a new harmonic balancer, new belts, even the engine mounts. Also  double check the power steering pump and fan while you are down there. If they havent been done yet:lower control arm bushings. 

The r53s are great cars, but will bleed your wallet. My reco has always been to keep $2k set aside every year for whatever comes up. Some years I only did oil changes, other years I got stung. These cars are getting up there in years and many people did not take care of them or keep up with the pricey maintenance. 

A note about rust: keep an eye on the rust around the rear tail lights. This is a very typical and very pricey to fix. The issue starts between two pieces of sheet metal on the inside, so that by the time you see the small bubbles, you are already sunk. I caught mine early when the first 2 bubbles showed up and managed to squeeze in under the warranty limitation to have it fixed: both entire rear quarter panels were replaced by BMW to a tune of $6k. 

Greetings Noobe.
You should notice when you post a new topic that there are options for which Mini/MINI you want to post about. If you choose the first option (All) and then post about your late model BMW MINI, you will get flack from Classic Mini purists like BC (and others) that you didn't ask for or deserve. So post away, but if you want to contact the other New MINI owners and not get flamed, choose the MINI (new) option. Cheers!

minimejcw..  most of the guys here on classic minis.. NOT bmw minis.. might try the north american motoring website..  later bc

Hi to all you mini cooper owners! 

1 week ago I just acquired my first mini...it's a 2005 S JCW model. ..the previous owner has done a lot of mods to it, 15% Alta pulley, Alta exhaust, Alta IC, Alta CAI and coil upgrades. ..other upgrades also includes fully adjustable coil overs on all 4 corners. ..back in 2005 I wanted to buy one of these cars but Mini dealership wanted 42k for the JCW model so I bought a 2005 Mustang GT instead, that was only $33,500, like 9k cheaper. ..so here it is 13yrs later and picked one up for $2500 with a blown head gasket and 150k miles...so what I need to do is get this car road worthy and reliable again cuz I have to drive it back to California from North Carolina. ..I have done a lot of research on the 1st Gen minis and have to give Mod mini on YouTube a shout out cuz he has provided me with a lot of knowledge about the known problems these little cars have not to mention that he makes great videos. ..the first thing I did was ordered a JB Performance blower, gasket set, Mishimoto aluminum radiator, aluminum coolant tank, 2 02 Sensors, t-stat, all new hoses, crank and cam sensors and ARP head stud set.

Previous owner already installed new timing chain and water pump. ..he told me that it started leaking coolant almost right away. ..I asked him if he had the head checked and resurfaced, which he didn't so I will have the head sent to the shop for the full work up...after I get the car up and running again I will verify that the fan is working ok. ..also, the PO did not use new head bolts so there were many mistakes on his part ...PO told me that he had 130psi compression across all cylinders, does that sound okay? ...I'm familiar with normally aspirated engines but this is my first car with a supercharger. ..I really want to do it right the first time. ..I also plan to have the shop tap and plug the hole that is known to fall out the head. 

Thanks everyone for meeting me, I look forward to meeting you guys and discussing many topics about these exciting little cars. 

I drive a semi truck for a living OTR and looking forward to going down the road in the other extremely tiny car