[Healeys] Adjusting Valve Rocker Clearance

healeyguy at aol.com healeyguy at aol.com
Sat Mar 3 11:39:53 MST 2012


Folks
Valve adjustment, while very important, is not that complicated. We are trying
to get the valve lash set at factory or aftermarket cam specs while the lifter
is setting on the base circle of the cam lobe. Looking at a AH six cylinder
cam you will see that the base circle is slightly more than 50 % of the cam
lobe profile. The lifter contact area with the cam lobe is minimal even with a
badly worn lifter.

Another interesting factoid is that the first lobe on the cam shaft from the
front, cylinder #1 exhaust is exactly 180 degrees off from the last cam lobe,
cylinder #6 exhaust. This fact will make the valve adjustment process much
less time consuming yet be as accurate.

By bumping the starter with valve cover removed it is very easy to get the
last valve spring from the back to completely compress, just watch it as your
pushing the button on the starter solenoid, and then you set the lash on the
first rocker arm from the front. Spin the starter to depress the second spring
from the rear and adjust the rocker on cylinder #1 intake.  Happens to be the
second rocker from the front! You continue the process front to back to until
all the valves have been adjusted. By the way don't get confused when you
finish the third cylinder. I don't do the valves in that order but it makes it
easier to keep track.  This way you don't have to find top dead center on the
pistons or concern yourself if you are off the timing mark by a few degrees.
You can be off a lot and still be on the cam lobe base circle but using this
method will produce very good results and it is a lot faster. Works on the 100
four cylinder cars too.

Aloha
Perry


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