1275 Head Swap

[MrIan]

Just an idea for later in the year maybe. Boris has a 1275 Marina engine fitted but also in my stocks of bits n bobs n rubbish I have a 12G940 A series head (of off a 1300GT i'm sure). It's the large valve type with twin valve springs but also 11 stud (well 10 + 1 bolt) so the 2 extras wouldn't have anything in them.
I will be using the head later on it's original engine in my mini but thought I might get some benefit from it by fitting it on Boris for now.
Would this fit ? Would there be any improvement ? is there any point ?

[bmcecosse]

Yes - worth it. Drill and tap for the extra studs if you wish....

[philthehill]

A good number of 10 stud and one bolt heads have been converted to pure 11 stud heads at some time my own head/block included.
The only proviso when converting to 11 stud is that the 11th stud is not tightened any more than the original torque for the bolt as there is a risk of breaking it out of the block as the casting thickness in the area of the 11th (front) stud/bolt is quite thin and that is why the smaller diameter bolt was fitted at a reduced head torque of only 25 ft lb.

9 stud 940 heads can be converted to 11 stud specification with very little difficulty as there is a casting web at the front and rear of a 9 stud 940 head that can be drilled right through using the head gasket as a location template for both head and block.

[MrIan]

As I'll be putting the original head back I doubt I'll get the block drilled n tapped for the extra bolt and stud. As long as it'd be ok to do that (or rather not to !!)

[bmcecosse]

As long as the head surface is flat it will be fine.