my head hurts......

Post by **d_harris** » Mon Jul 31, 2006 6:21 pm

Does anyone have a list of heads that can be fitted to a 1098 and what special properties they give (ie, we all know the 940 is a performance head)

Post by **bmcecosse** » Mon Jul 31, 2006 7:15 pm

12g295 head (bigger inlet valves) was the head on the MG 1100 - with twin carbs and 3 branch exhaust it gave a giddy 55 bhp. Early version of that head was 12G206 - also bigger inlets, just no location ring for inlet stub locators. Standard on the 1098 is of course the 12G202. You could also fit Cooper S head AEG 163 - which has biggest inlets of them all AND biggest exhausts. Which is precisely why they are prone to cracking between the seats. So - 206 or 295 give a bit of a boost - but should be skimmed 40/60 thou to raise the CR - but they are otherwise straight bolt on addition. The 940 needs exhaust valves sinking by 40 thou OR pockets in block - and needs 1275 gasket and rockers. It does go very well though!

Post by **rayofleamington** » Mon Jul 31, 2006 9:33 pm

Hi Dan - if you ever need technical head info, this site is fab:

http://drcwww.kub.nl/~bogaard/heads.htm

Post by **zippy500** » Wed Aug 02, 2006 10:33 am

hi,

This very confusing with all these heads available.

Are there noticeable gains to be made.

Which would be the best/easily availble head to fit to a 1098 (without needing machining).

do the 1098 rockers fit these heads or do you need the 1275 bits.

What does it mean when peeps refer to have to 'port the head to fit'

Sorry for all the questions. but i'd like to be enlightened!!.

Thanks

Post by **Kevin** » Wed Aug 02, 2006 11:03 am

The definative answers and everything to do with the `A` series engine is given in David Vizards book Tuning the `A` Series Engine this is available new and also turns up on Ebay have a look at..
http://www.amazon.co.uk/gp/product/1859 ... e&n=266239