PRW 33 PQ Series Aluminum SB Ford Shaft Mount Rocker User Manual
Page 2
2) Make certain that you have all the tools necessary to complete the project.
3) Assembly lube and/or lubricating oil should be readily available for installation.
PQ
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Shaft Rocker Arm System Installation:
Step 1: The rocker arm roller tips must be immersed in oil for at least 3 hours prior to installation. This
will allow full lubricant penetration of the roller tip and axle. A disposable aluminum baking pan works
well for this purpose.
NOTE: It is critical to thoroughly pre-oil all shaft rocker components prior to use.
Step 2: Thoroughly inspect cylinder head(s) to ensure that there are no obstructions that may impair the
rocker stands from bolting into place on an even plane.
Step 3: If installed, remove any rocker arm studs from the cylinder heads. Inspect all rocker stud bolt
holes to ensure that the threads have not been damaged during removal of the studs. Utilize a thread
chaser to assure the threads are clean and to mount the rocker stands securely to the cylinder head.
Step 4: Verify that all rocker stand bolts can be threaded to operational depths through the rocker shafts
and into the rocker arm stud holes prior to applying torque to any of the rocker stand bolts. Confirm
adequate depth for rocker stand bolts with calipers or depth gauge. Check rocker arm shaft bolts to be
certain that none extend beyond the depth of the rocker arm stand. If they need to be shortened, use a
bench grinder. Clean up any modified threaded bolt ends with a thread chaser after grinding.
Step 5:
OEM Ford Cylinder Head(s) – 5/16” Rocker Stand Bolts: The use of longer than stock valve stems
are NOT recommended for use with 5/16” Rocker Stand bolts and SVO/OEM Ford cylinder heads. If
longer than stock valve stem lengths are utilized, the cylinder heads should be machined to accept 7/16”
rocker stand bolts to be used in conjunction with rocker stand shims necessary to correctly adjust valve
train geometry. Shimming may not be required if cylinder heads are equipped with standard length intake
and exhaust valves.
Aftermarket Cylinder Heads with 7/16” Rocker Stand Bolts: If longer than stock valve stems are
being utilized, rocker stand shims will be required. If required, make certain to utilize four (4) equal
thickness combinations of shims under each pair of rocker stud holes. Three (3) thicknesses of rocker
arm pedestal shims are included (.100”, .050”, and .025”) and eight (8) each are included with each kit.
Carefully inspect the rocker arm geometry to ensure that the roller tip is centered (or slightly over center)
and nearly parallel to the valve spring retainer. Shims should be added under the rocker stand to raise the
shaft proportionate to the added length of the valve stems.
Special Note: For valve lift greater than .650” for small block Chevy and Ford, the shaft height
should be lowered by half the difference between actual lift. For less lift, the stand height should be
raised by half the difference between the above noted lift and actual lift. (i.e. for a small block with .750”
of valve lift, the rocker shafts should be .050” lower. For a small block with .600” of valve lift, the rocker
stands should be .025” higher.).
Step 6: Torque the 5/16” or 7/16” rocker arm stand bolts to specifications provided on Page 4. Any bolts
that thread into an intake runner should be coated with a thread sealant such as Loctite®. Installation
without shims may require filing .020”-.025” from the overall length of the pedestal hold down bolts to
prevent them from “bottoming-out” in some aftermarket cylinder heads.
Step 7: Install the rocker arms onto the rocker arm shaft one pair at a time. If pushrod length has already
been determined and pushrods installed, back the adjusters out until the base of the adjuster seats against
the rocker body. If pushrod length has not been verified, please refer to the Section: Pushrods;
Checking to Determine Proper Length to ascertain the appropriate pushrod lengths. Once completed,
install the pushrods, and continue Step 7 as detailed below.
Make certain that the number 1 cylinder is at TDC and the pushrods are properly seated in the valve lifter
at one end and the valve lash adjuster at the other. The rocker arms should rest in the pedestal/stand