1.158" (29.4) dia exhaust valve for 12G940 casting.
Our race valves are produced in EN214N steel and rquire Manganese/Silicon bronze alloy valve guides. They are stellite tipped and use the later narrow, single collet groove and current valve head shapes.
As it is possible, even common, to swap one head for another on 1275 engines, it is quite easy to become confused, or worse yet, confuse the parts-guy when it is time to order new valves! Be aware that if the head has been worked on previously, it may have oversize valves; it may have undersize if seats have been installed. Unless you are 100% sure what is in your cylinder head, it is a good idea to remove a valve for accurate measurement. There are two lengths used (nominally 3.52" & 3.57") three different keepers, (wide, narrow, and three-groove) and many different head diameters! These valves are in stock at Mini Mania!
Note that 12G1316 (Smog-Type), all variations of the 12G940, and the latest CAM head castings all use the following 3.57" long valves.

1.158" (29.4) dia exhaust valve for 12G940 casting.
Our race valves are produced in EN214N steel and rquire Manganese/Silicon bronze alloy valve guides. They are stellite tipped and use the later narrow, single collet groove and current valve head shapes. These valves are heat treated to eradicate wear from unleaded petrol As it is possible, even common, to swap one head for another on 1275 engines, Be aware that if the head has been worked on previously, it may have oversize valves; it may have undersize if seats have been installed. Unless you are 100% sure what is in your cylinder head, it is a good idea to remove a valve for accurate measurement. There are two lengths used (nominally 3.52" & 3.57") three different keepers, (wide, narrow, and three-groove) and many different head diameters! These valves are in stock at Mini Mania!
Note that 12G1316 (Smog-Type), all variations of the 12G940, and the latest CAM head castings all use the following 3.57" long valves. As it is possible, even common, to swap one head for another on 1275 engines, be aware that if the head has been worked on previously, it may have oversize valves, it may have undersize if seats have been installed. Unless you are 100% sure what is in your cylinder head, it is a good idea to remove a valve for accurate measurement. There are two lengths used (nominally 3.52" & 3.57") three different keepers, (wide, narrow, and three-groove) and many different head diameters.

1.15" dia exhaust valve.
Our race valves are produced in EN214N steel, stellite tipped and use the later narrow collet groove and current valve head shapes.
As it is possible, even common, to swap one head for another on 1275 engines, it is quite easy to become confused. Be aware that if the head has been worked on previously, it may have oversize valves, it may have undersize if seats have been installed. Unless you are 100% sure what is in your cylinder head, it is a good idea to remove a valve for accurate measurement. There are two lengths used (nominally 3.52" & 3.57") three different keepers, (wide, narrow, and three-groove) and many different head diameters. All variations of the 12G940, and the latest CAM head castings all use the 3.57" long valves.

1.043" (26.5mm) Dia x 3.44" exhaust valve for all small bore castings.
. Our race valves are produced in EN214N steel and rquire Manganese/Silicon bronze alloy valve guides. They are stellite tipped and use the later narrow, single collet groove and current valve head shapes.

The stock intake valves for the 948/1098cc cylinder heads are 1.06" or 1.15"; if you want better performance you need bigger valves. Our special 1.22" intake valves will fit all small bore heads and only available with triple collet grooves. Our race valves are produced in EN214N steel, stellite tipped and PLASMA treated to eradicate wear from unleaded petrol.

1.220" (31mm) dia x 3.57 exhaust valve.

Our race valves are produced in EN214N steel and require Manganese/Silicon bronze alloy valve guides. They are stellite tipped and use the later narrow, single collet groove and current valve head shapes.

As it is possible, even common, to swap one head for another on 1275 engines, it is quite easy to become confused, or worse yet, confuse the parts-guy when it is time to order new valves! Be aware that if the head has been worked on previously, it may have oversize valves; it may have undersize if seats have been installed. Unless you are 100% sure what is in your cylinder head, it is a good idea to remove a valve for accurate measurement. There are two lengths used (nominally 3.52" & 3.57") three different keepers, (wide, narrow, and three-groove) and many different head diameters! These valves are in stock at Mini Mania!
Note that 12G1316 (Smog-Type), all variations of the 12G940, and the latest CAM head castings all use the following 3.57" long valves.

Triple Groove Collets - 2 required per valve. For valve stems with a single, narrow groove, use 88G459. Also fits Sprite , and MG Midget .

1.402" (35.6mm) dia x 3.57" long intake valve. Our race valves are produced in EN214N steel and are stellite tipped and use the latest triple collet groove and current valve head shapes, plasma heat treated for eradicating unleaded petrol wear. As it is possible, even common, to swap one head for another on 1275 engines, it is quite easy to become confused, or worse yet, confuse the parts-guy when it is time to order new valves. Be aware that if the head has been worked on previously, it may have oversize valves, it may have undersize if seats have been installed. Unless you are 100% sure what is in your cylinder head, it is a good idea to remove a valve for accurate measurement. There are two lengths used (nominally 3.52" & 3.57") three different keepers, (wide, narrow, and three-groove) theses are the 3 groove a plus type.

1.311" (33.3mm) dia x 3.57 long intake valve.
Our race valves are produced in EN214N steel and require Manganese/Silicon bronze alloy valve guides. They are stellite tipped and use the later narrow, single collet groove and current valve head shapes.
As it is possible, even common, to swap one head for another on 1275 engines, it is quite easy to become confused, or worse yet, confuse the parts-guy when it is time to order new valves! Be aware that if the head has been worked on previously, it may have oversize valves; it may have undersize if seats have been installed. Unless you are 100% sure what is in your cylinder head, it is a good idea to remove a valve for accurate measurement. There are two lengths used (nominally 3.52" & 3.57") three different keepers, (wide, narrow, and three-groove) and many different head diameters! These valves are in stock at Mini Mania!
Note that 12G1316 (Smog-Type), all variations of the 12G940, and the latest CAM head castings all use the following 3.57" long valves.

1.402" (35.6mm) dia x 3.57" long intake valve. These are the 'waisted stem' design that provides maximum air flow needed for high performance applications.
Our race valves are produced in EN214N steel and rquire Manganese/Silicon bronze alloy valve guides. They are stellite tipped and use the later narrow, single collet groove.
As it is possible, even common, to swap one head for another on 1275 engines, it is quite easy to become confused, or worse yet, confuse the parts-guy when it is time to order new valves! Be aware that if the head has been worked on previously, it may have oversize valves; it may have undersize if seats have been installed. Unless you are 100% sure what is in your cylinder head, it is a good idea to remove a valve for accurate measurement. There are two lengths used (nominally 3.52" & 3.57") three different keepers, (wide, narrow, and three-groove) and many different head diameters! These valves are in stock at Mini Mania!
Note that 12G1316 (Smog-Type), all variations of the 12G940, and the latest CAM head castings all use the following 3.57" long valves.

1.259" (32mm) dia x 3.57 long EXHAUST valve.
Our race valves are produced in EN214N steel and rquire Manganese/Silicon bronze alloy valve guides. They are stellite tipped and use the later narrow, single collet groove and current valve head shapes.
As it is possible, even common, to swap one head for another on 1275 engines, it is quite easy to become confused, or worse yet, confuse the parts-guy when it is time to order new valves! Be aware that if the head has been worked on previously, it may have oversize valves; it may have undersize if seats have been installed. Unless you are 100% sure what is in your cylinder head, it is a good idea to remove a valve for accurate measurement. There are two lengths used (nominally 3.52" & 3.57") three different keepers, (wide, narrow, and three-groove) and many different head diameters! These valves are in stock at Mini Mania!
Note that 12G1316 (Smog-Type), all variations of the 12G940, and the latest CAM head castings all use the following 3.57" long valves.

For valve stems with 3 grooves, on some A-Plus heads, use CAM6975 keepers. Order the keepers to go with the valves you will be using! Also fits the Sprite, MG Midget, and Morris Minor. This is for a PAIR of collets - 8 needed per head.

New competition valve cotter, these are precision CNC machined from 4340 and heat treated to a better spec than EN24T and claimed to be stronger in fatigue life. This is for one pair (two halves) - 8 are needed for one A-Series head.

These are made to RACE specification as the only current type available are not adequate for performance heads or valves. We tried everything else available and decided to go one better in quality and fitment, do not take a risk--buy the best available on this part.

All the early heads used the 2A11 cotters, noted by the wide slot in the valve. Current production race quality valves and most aftermarket valves, use the 88G549 keeper with a single narrow groove. Valve stems with 3 grooves on some A-Plus heads, use CAM6795 keepers. Order the correct cotters to go with the valves you will be using. Two halves equal one cotter for one valve, order 8 for 1 complete cylinder head.