Valve sound

[jondee86]

Hmm.. it seems that something ugly has been going on inside
your engine

The valve clearances are measured between the "back" of the
cam lobe (base circle diameter) which is a non-wearing part of
the lobe. If the clearances are greater than specified in the
manual, then it is the valve or shim that are worn. This will affect
the valve timing (open later, close earlier).

The shape of the lobe, in particular the height of the tip of the
lobe, affects the valve lift. On a standard cam the tip should be
more or less symmetrical (evenly rounded), smooth, and without
evidence of scoring or pitting. All lobes on the intake cam should
be of uniform height, and the same with the exhaust cam.

If there is an angle showing on the leading side, and the tip of
the lobe appears flattened or blunt, then you should consider
replacing the camshafts.

I would recommend that you have the head rebuilt at the same
time, to make sure the valves, seats and guides are all in good
condition, before installing new camshafts.

Cheers... jondee86