I recently found out my r53's head is junk and unrepairable. im looking to buy another one, however... im getting confused on which to buy. i see some people say all will interchange between 2002-2007. i see forums saying theyre not all the same. i see where the s is supposed to have stronger valves or something. if its true that not all heads are the same, then which casting code is the correct one for my w11? ive seen the following upon researching:

04777751A
04777751AB
04777751AB A
04777751AB C
all of those claiming to fit any 02-07 engine, whether it be w10 or w11. the head i pulled off mine is an "AB A". BUT.. ive got 3 other minis, all r50s.. and ones ab a, and the other two are ab c. NEVER have they been changed. And on top of that, ive checked my buddys r53 head code and his is an "ab". Is there any relevance in these or can i throw any head on there? i know the jcw head in fact IS different in the way the exhaust is ported 4mm. other than that, are they all the same? ive done all kinds of searching and havent seen anything more relevant to my question other than someone saying that about the valves are different?
any help is appreciated, thank you!

 

W10 or R50 cylinder and W11 R52/R53 cylinder heads are very much the "same" except for the valves in W11 are a bit stronger and thicker than those are in W10 due to the fact that W11 is rated at higher horsepower. GP and JCW head are the somewhat upgrade over the regular R52/R53 by having the exhaust ported 4mm bigger (which isn't much as to consider an upgrade). For casting, according to realoem the w10 and w11 are interchangeable parts, so as long as you buy/remove from a R52/R53 the casting can be neglected.

 

The exhaust valves are definitely different material. You don't want to use the wrong valve material, it would be easy to damage them given the forced induction of the R53.

Here is some good info:

https://www.northamericanmotoring.co...oper-here.html

https://www.northamericanmotoring.co...ec-engine.html

https://www.northamericanmotoring.co...-the-team.html

 

Both posts above are correct, the heads themselves are the same and casting numbers won't reflect the differences in the valves, so you can't go by that.
You'll either have to make sure the replacement came off of an "S" or do a valve job on it with the appropriate valves.

 

BlwnAway, I'm stuck in limbo and hoping you can help, please. My son has started the mini craze in our family. I vowed never work on a car again, but can't help myself now that we have a mini. We will have more soon!
I'm now replacing the cracked head on his 03 mini s. The non "s" heads sell for less and in some cases, either the seller doesn't know what car they came off of or doesn't know the information you shared in this discussion. So, the questions are:

1. Can I buy a non "s" head and use the valves from my son's cracked "s" head (having the machine shop do the work)?

2. Can I do it myself?

3. Is there a way to identify the correct "s" valves?

4. Will a average auto machine shop understand what needs to be done if I explain?

Thanks in advance!

 

Both heads are the same with ONE major exception. Like they say above.. the Valves. If you have the S engine , then you need the S head. IF you can see the Head.. the Intake Valve for the S , will have a "l " cast on the intake valve surface. the NON S will not. The Exhaust valve will have a 'Dot' in the center of the valve head and the non S will not. Hope this helps.