Your Imp cylinder head needs very thin tappet shims, why?

Hello Impers!

 

A new R 20 Rootes comps camshaft ready to fit, note the closed hole in the tappet cover as this 998cc Imp engine will use an electric fuel pump. This type of camshaft needs timing with a dial gauge, you can not use the method as per the normal or sports Imps.

Some ideas.

 

This often happens because the valves and or seats have been over cut

And the valve has started to disappear into the head too far? New seats and

Valves are the best idea then.

 

You can also cut a bit off the end of the valve stem, so use a thicker shim?

 

With very thin shims you run the risk of the inside of the bucket sitting not

On the shim but the cap it rests in, check this as you will reach a point where

Nothing is changing unless you cut the cap down as well!

 

Roy