valve stuff

[IainB]

think I;m wrong tho

Is it the groove round the TOP of the valve stem that holds it in position ?

Yup - I had a look for this last night, but couldnt find anything... and then the diagram I typed out, looked pants when I previewed it - so I deleted the whole thing and didnt post....

Im wondering if these have an extra 'groove' for retaining a collet - but im really clutching at straws on this one but personally, I dont know why its needed, unless the A-Series has a problem with harmonics on tuned engines?

[doll]

Anyone know what 'triple collet grooves' means?

http://www.minispares.com/web/Item/C.../InvDetail.cfm

Triple collet grooves are the amount of collet groves machined into the top of the valve, so in this case there is three.