Tappets

[carlsberg]

:) :confused: Can anyone please tell me about the tappets on the V6 12valve alfa engine
how are they adjusted?
is it manual, shims or hydraulic.
what are the clearances inlet and exhaust.

I don't want to take the top off until I know what I am up against.At the moment they are just slightly noisy.... is this usual?

thanks in advance

[chris.richard]

Can be wear on the exhaust cam lobes - dodgy lubrication I believe.

[David May]

On the 12V engines the exhaust clearence is a normal rocker and screw adjuster (my notes say exhaust valve clearance cold 0,30mm) but the inlet is a fiddly shim job under the tappet bucket (inlet valve clearance cold 0,40mm.) I never got mine quiet but that was probably the custom cams.

[CorseChris]

It's usually the exhaust ones that need doing and speaking for myself, every 12V I've looked at so far has had wear on the exhaust lobes and followers to some degree. My 155 V6 12V motor was in a really bad way. Feel the side of the tip of the cam lobe - if it's got a sharp lip, its' likely worn. You can usually see some 'contour lines' around the nose where it's gone through the hardening. In bad cases, you'll be able to see severe pitting and dishing of the follower.

As Dave says, inlets are shims, exhausts are pushrods & rockers. To avoid hassle, buy a pair of cam cover gaskets and a set of 6 spark plug hole seals BEFORE you take it apart! Also check that the inlet runner seals & clips are in good order as you'll be taking these off to get at the rear bank of course.

You'll ideally need a set of angle-ended gauges to measure the inlet gaps.

If you need to change shims on inlest, the cams are pretty easy to get out once you have persuaded the pulley to let go of the taper. This can be complicated by poor access but is a simple enough job with a hub puller. Can be done with cambelt undisturbed if you are careful but is easier if you are changing the belt as well.

They keep on running even with badly worn components but can sound awful (like my 155 was until I swapped cams & followers). I think I've only ever heard one really quiet 12V motor, the majority are a bit 'tappety'.

Have fun!! :)