12G940 Cylinder Head

Post by **Jefftav** » Tue Sep 12, 2006 9:15 am

Hi, Just a query about a cylinder head I have. It has the numbers 12G940 stamped onto it but they have been stamped over with the number 208 - so that you can barely make out 12G940, I had to use a magnifying glass to work out the numbers.

The head also has 13A stamped on to it and 19 under the themostat housing.

I have tried it on a 1275 block and it seems to fit OK and the valves seeem the normal size as far as I can measure without taking them out of the head (28/29mm & 32/33mm)

I intend to use this on a 1275 engine block but would anyone have any idea why it has 208 on the head - just in case I am making a mistake.

Also any ideas on how to tell if the head is already converted with hardened valve seats to run on unleaded fuel? It will be used on long journeys so I think will need to be capable of using unleaded.

Thanks for your help, Jeff

Post by **bmcecosse** » Tue Sep 12, 2006 10:19 am

Dunno about the overstamping Jeff - not seen anything like that. Does the head look standard - or has it been obviously machined or polished up in any way ? I would just use it! I am told that hardened inserts should be obvious on removing the exhaust valves - but I have NEVER seen any inserts (except when fitted as an aftermarket conversion) - and I have read somewhere that it was just a 'heat treatment' process thta was used to harden the seats along with different valves. Well done finding a 1275 block - good luck with it!

Post by **Kevin** » Tue Sep 12, 2006 10:45 am

but I have NEVER seen any inserts (except when fitted as an aftermarket conversion)

Well I have seen the inserts on a nineties Classic Mini 1275 head and this came of a low mileage car with no alterations from new.
I would love to know how the heat treatment process would work compared to the stainless inserts.

Post by **bmcecosse** » Tue Sep 12, 2006 8:41 pm

I agree Kevin - don't understand - but at least someone has seen these famous inserts. Doubt they are stainless though!

Post by **Onne** » Tue Sep 12, 2006 8:48 pm

You may be able to see the inserts in this picture. Not exactly a 12G940 head, but a sidevalve!

Edit; I don't know if they were actually fitted at the time, this was a bit half way.
So if they're not, please ignore this freshly machined engine

Onne

Post by **bmcecosse** » Tue Sep 12, 2006 8:55 pm

I used to have 3 Morris 8E - at the same time with the early version of this engine. Real bu99er to adjust the tappets!!

Post by **Onne** » Wed Sep 13, 2006 12:39 am

I know, that is also why I had it made unleaded!

Post by **bmcecosse** » Wed Sep 13, 2006 7:23 am

At least the 8E had a little removable panel to give access - in the nearside inner wing - still difficult though!

Post by **Onne** » Wed Sep 13, 2006 10:26 am

And it does say adjuet when hot

I'd rather not with the manifold in the way!