1968 mini cooper mk 2 998cc cylinder head
1968 mini cooper mk 2 998cc cylinder head
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Discussion

jdominicd

Original Poster:

38 posts

224 months

Thursday 19th June 2008
quotequote all
Does anybody know what cylinder head will fit my mini cooper and which serial numbers are the correct ones without modification. My engine has the bipass hose. Mine is beyond repair and am looking for a replacement if anyone is out there that is willing to sell one to me.Please e-mail me on swissbrit@hotmail.com
Thanks
Andy

Cooperman

4,428 posts

271 months

Friday 20th June 2008
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The head casting you need is a 12G295. That is the 'small-bore open-chamber' head and it's vastly better than the later heads fitted to the Mini 1000. In fact it's the only head for your car as you'll have, or should have, the 'D-Top' pistons with raised piston tops in th shape of a 'D'.
You may find a 12G295 on ebay or a Mini specialist. Expect to pay around £70 for a decent one.

R4NDY

144 posts

245 months

Friday 20th June 2008
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Maybe worth checking that the cylinder head you intend to buy has not been skimmed to up the compression to fit a later standard 998 mini.

Dino42

151 posts

251 months

Friday 20th June 2008
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jdominicd said:
.. Mine is beyond repair ....
Really, are you sure?
Do bear in mind that any replacement you find will be equally as old as your head, they haven't made the 295 for nigh on 40 years, they're all going to need some work.

jdominicd

Original Poster:

38 posts

224 months

Friday 20th June 2008
quotequote all
thanks for the replies my head has a crack in it thats why its beyond repair, i believe a 998 non cooper head will fit but with a loss of power but would prefer the cooper one, has anyone got any telephone numbers of places where I can get one. This is the last thing to do on the car as I have just completed a nut and bolt refurbishment even had to weld in a replacement boot as the hold one was full of holes.

Cooperman

4,428 posts

271 months

Sunday 22nd June 2008
quotequote all
I wouldn't put any head on a genuine 998 Cooper except a 12G295. A standard 998 head has very small inlet valves and the combustion chambers really are a poor shape as well. You could gas-flow a standard head and then re-calculate the comp ratio and machine down to get it right, but even after all that it would not be as good as a standard 12G295, which was a very good head as standard in its day and even better with slightly bigger inlet valves and a light 'clean-up' of combustion chamber and inlet tracts.
The other alternative is to machine the top of the block to obtain valve clearance and get a 12G940 head from a 1275 cc car. these heads are much more plentiful, but still it requires block machining to be able to fit one and you may not want to strip the engine right down to do so.