O ring valve stem seal fitment

[Thomas.hewitt05]

Hi, Could someone show me how the o ring style valve stem seals actually fit.
Thanks.

[les]

After the valve is in the guide, the O ring type of seal is then fitted over the protruding valve stem. The type that fits over the top of the valve guide are apparently better, however I believe they require a guide that has a recess to secure the seal.

[rocco]

This is how I found the seal on the valves I removed:

20221015_113836.jpg (74.88 KiB) Viewed 186 times

[philthehill]

As regards the 'O' ring type seal you might as well leave them off for all the good they do.
The 'O' ring goes over the top of the valve stem and slides down into the bottom of the valve stem collet groove. The collets hold the seal to the bottom of the collet groove.
The seal that does work is the 'Top Hat' seal https://www.minispares.com/product/Clas ... o%20search but as Les indicates it does require the special grooved valve guide.https://www.morrisminorspares.com/engin ... l-p1209547
The top hat seals only need to be fitted to the inlet valves as with unleaded fuel the exhaust valve stems run hotter and need all the lubricant they can get to stop them sticking.
Rocco
The seal in your photo goes inside the shroud that fits between the spring and top cap.
Again the seal and shroud are useless and were soon ditched by BMC.

[rocco]

I took your advice Phil and bought the guides with the grooves and got them put in to the head already, top hat seals ready to fit.

[philthehill]

Well done