Small trick for checking certain types of tappet

[Pan Pan]

One of my cars has conventional tappets, where the rule of 9 can be applied, when adjusting the tappets, but working out when the open valve is at the top of the cam, can sometimes be a bit `hit and miss'
I have the tapering / tight thread type tappet adjusters, which allows me to put a long dowel (trimmed to fit tightly into the adjuster) into the end of it.
Consequently even the tiniest movements of the tappet, which are virtually invisible at the tappet itself, can easily be seen to ensure the valve is absolutely at the `no movement' point on the cam.
For cars with bolt and locknut type tappets a length of tube e.g plastic conduit, can be pushed over the locknut to get the same effect.
For me it takes the `did it move, or didn't it' guess work out of establishing the no movement point
of a particular tappet on the cam.