3 replies to this topic

[grahama]

Hi,

have just got the yellow bible, and to be honest am finding a little hard going !! Lots of info in there admittedly but as an amateur I am having to re read many times, ce la vie !!

He goes through, 0n P167, the cylinder heads and mentions several 12g940 versions up to the MG metro one. The lower down the list he goes he seems to like them more, or am I reading it wrong.

Therefore is a later metro 12g940 with the sculpted thermostat housing any better than a flat machined therm housing one from an earlier year?? (p169 and 170)

Are all 12g940s the same inside, I know some earlier ones had bigger inlet valves, but the later Metro one seems to have very similar valves.

Confused to say the least, can you enlighten me please !!

Graham

[dennismini93]

i havent red my yellow bible properly yet so i dnt know but hes on facebook if u need help

[TA2DMAC]

He's also on this forum. Send him a pm or post a question to him. I just got my Yellow Bible and still havent read it through. Maybe more experienced builders will add some input until Mr. Vizard can answer.

[Turbo Phil]

The early MG Metro had a larger 35.7mm inlet, this was downsized on the later unleaded heads to 33.3mm, which is the size the all other 1275 Minis & Metros had, all sported the 12G940 casting number.
The Cooper S heads were a different casting number, the early heads featured a larger 31mm ex as well as the bigger inlet, but the exhaust was downsized on the later heads to help avoid cracking between the seats.

It doesn't matter if you use the earlier or later 940 heads at all.