Many ford and chrysler engines had non-adjustable rockers once they
started using hydralic lifters. Chevy continued to have an adjustable
rocker with a friction nut on the top of each rocker stud. (The nice
thing about that is that it makes going back to a mechanical lifter
easy.) Static adjustment presumes the lifters are pumped up. Tighten
the nut until the play is removed. Usually by feeling/turning the
pushrod. Then tighten the nut 1 more full turn to center the plunger
inside the lifter. With a hydralic lifter the goal is to have some oil
supporting the plunger inside the lifter but have it neither bottomed
out or at the top of it's range. The leakdown of the lifter will
prevent the valve from staying open. But the leakdown is slow enough
that it will not collapse when the cam pushes it up. With
non-adjustable rockers basically the tolerances are engineered into the
components to achieve the same thing. Ultimately you want an oil
cushion that removes all the free play in the valve train. Makes for
quieter valve operation and eliminates the need for periodic
adjustments. But has issues at higher rpm because the lifter
eventually gets pumped up to much. It is one of the first causes of
valve float where the valves do not close properly. If you floor a
hydralic lifter engine it will experience valve float at some point and
not go over a particular rpm. Of course this rpm is usually higher
than recomended so try this with an engine you don't care about.
Performance high rpm engines still use mechanical lifters to avoid this
problem. Most motorcycles still do too because their rpm range can be
over 10k and sometimes as high as 12k. At some point the springs
simply do not close the valves soon enough. But this is usually a lot
higher rpm.

He should not have a valve adjustment problem on an engine this new.
Unless it simply never was adjusted correctly from the start.

Mr Wizzard wrote:
"James" wrote in message
ink.net...

Hydralic lifters almost never get out of adjustment but it won't hurt to
try.

Forgot to ask in previous post.... How does the "static"
adjustment work with hydralic lifters? All of my old cars
(with hydralic lifters) never had adjustments on the rockers.
So it would seem "odd" to me to have both. Anyways, if
so, I wonder how that would work? (static adjustment
with hydralic lifters) - do the lifters stay pumped up, or
do you do that "one turn" into the lifter into the colapsed
mode?










If you really have a lifter that is clacking it may be collapsed.
With the valve cover off you may be able to get a better feel for the
source
of you noise. Valve train nise can be felt and changed by pushing on the
rockers while the engibe is idling. It is messy. They make clips that
can
be placed on the rockets to limit the oil spray.

"Mr Wizzard" wrote in message
. ..
I brought this up last year, and concerned about it again.
Mercruiser 3.0L Alpha one (130HP?). Does anyone
know if this engine has hydralic valve lifters, or adjustable?
I'm assuming that they are adjustable. Anyways, 3 questions:

1) Adjustment procedure, is it 1/2 turn, 3/4, or 1 turn
past zero lash ? Whats Mercruiser say, whats common.

2) How do you get the valve cover off with that bracket
on top? There is a big plate steel bracket on the left
that has a wing that bends in to hold throttle cable.

3) What the best way to turn the crankshaft for the
valve adjustment? Take plugs out, and just grab
the belt and man-handle it around like that ?

I'm concerned about this clacking noise that I've been
hearing since last year, ahortly after I bought it new.

Also, been hearing a "huffing" noise near the carb and
manifolds - sounds like one cylinder is "huffing" through
the carb or something. Hard to tell if its one "huff" for
each cylinder at idle, or just one cylinder out of four.
The boat runs fine. Idles well, accelerates, high speed...
There is nothing wrong with the way it runs, just wondering
about these noises (at idle) - this valve noise, and this
"huffing" type noise near the carb.


Thanks!