This broken
rocker arm is what sent me on the search for an economical
rocker arm that would last more than one season. You can
see the break on the bottom of the rocker arm.
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The Stage
VI Mopar heads on this engine uses all OEM style valve
gear. The rocker arm shaft pedestals, mounting bolts and
oiling system are all stock design. |
After determining
what length pushrod we needed a call to Comp Cams and
two days later we had the set of HiTech pushrods we needed.
We used part number 7934-16, which are different than
OEM in that both ends are "ball-style" and not
"cup-style" on one end.
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This is
the Pro-Magnum kit #1321-16 for big block Mopars. Now
is the time to have your rocker arms honed out to assure
.004-.006" clearance if you are using a roller cam
or cam lift over .600". Take the shafts and rocker
arms to a competent machine shop. This is a simple and
inexpensive operation but can save you hundreds of dollars
in the long run. |
One reminder
as you install the rockers on the shafts. You have to
determine which side you are setting up because the oil holes
are not in line with the mounting holes. Make sure the
oil holes are pointed towards the outside exhaust side
of the head. This will assure correct oiling when the
rocker arm is lifting the valve spring and valve.
|
Comp Cams,
myself and most engine builders agree that it is critical
to use a moly-based assembly lube on an assembly like
this, especially for initial startup to prevent galling
of rockers to the shaft. It is a good idea to make sure
you pre-lube the roller tip as well. |
This is
how the rocker arms looked after some minor grinding on
the stamped-steel spacers. Try to get the rocker centered
on the top of the valve and be sure to have .035-.040"
side clearance per pair of rocker arms. Even though it
is a little more work, the best results setting side clearance
and positioning of the rocker tip on valve is best done
without pushrods being installed.
|
A little
closer view of the installed rocker arms. The spacers
are easily visible and easily filed off to provide the
correct side clearance. Positioning over the tip of the
valve is important, try to keep them as centered on the
valve as possible. |
