Can you help Identify 1275 heads

[oldmod1968]

Hi,

I have two 1275 heads.

Head 0ne
- advertised as a 1300
- casting number 12g940 in the normal place, under the rocker shaft is 10 D 4
- it has a heater valve and aperture
- what looks like a proper plug with a std Screwdriver head in the hole where the bypass should be.
- The thermostat housing looks like there is a proper spacer under it and housing has two pipe outlets.

Head 2
- Red in colour and was sold as unleaded.
- No casting numbers in the centre of the head.
- Near the thermostat there are large numbers 20L3 but theses distorted and almost look like there was a plate fitted.
- At the heater valve end the screw threads for the valve are there but the water hole is not drilled out .
- The casting is 12g940B number is across this end of the head.
- But this head does have a bypass pipe.

Can anyone help me identify what I have . I will refurbish both and fit to Minor and Midget.

thank you

[brucek]

Can you post photo's? lots of 1275 heads around all with the same casting number. Photo may help determine the types you have

[oldmod1968]

How do I post photos, I will take some tomorrow.

[bmcecosse]

Just standard 940 heads - no special advantage one over the other - although the lack of bypass is a definite bonus!

[brucek]

Have a read of this sticky to find out how to post a photo

http://www.mmoc.org.uk/viewtopic.php?f=20&t=31197

[oldmod1968]

How can I tell if the head is actually unleaded? My thought was that the red head was unleaded but it has a bypass pipe. can that be the case?

[brucek]

The paint is no clue sadly as many of these heads were painted red whether unleaded or not. If you can find out what car the head came from it may be possible to tell if it is unleaded or not.

There are loads of threads and discussions on the forum about which 1275 heads are best and whether you actually need an unleaded head or not. Some say you do, some say you don't. With two very similar heads in your posession, you could just put one on - perhaps the one you think is unleaded - and use standard unleaded fuel. It will be fine for a very long time and, if you do start to see some deterioration in performance that can be linked to valve recession, you have another head to swap in it's place and then you can get your original head refurbished with hardened valvve seats so you'll then know it is an unleaded head! If the original head shows no signs of trouble then it will be fine anyway and it would be OK to assume it was an unleaded one!

[bmcecosse]

The head with no bypass will be 'unleaded'....you should be able to see seat inserts when the ex valves are removed.