COMP Cams Ultra Pro Magnum XD Roller Rocker Arms User Manual

1

COMP Cams®

3406 Democrat Rd.
Memphis, TN 38118
Phone: [phone]

Part #151

Revised 7/9/14

Toll Free: 1.800.999.0853
www.compcams.com

Ultra Pro Magnum™ &

Ultra Pro Magnum™ XD Roller Rocker Arms

Thank you for choosing COMP Cams® products; we are proud to be your manufacturer of choice. Please read this
complete instruction sheet carefully (including the application notes section) before beginning installation and also
take a moment to review the included limited warranty information.

Installation:

1. With the valve covers off and old rocker arms removed, the first step will be to inspect the pushrods. COMP

Cams® strongly suggests when installing new rocker arms (of any kind), that new COMP Cams® pushrods be
incorporated to ensure that all mating surfaces are fresh to prevent any premature failures. If you are using the
old pushrods, examine the ends of all pushrods for any flaking or galling. Any imperfections on the ends of the
pushrods will result in either rocker arm or lifter failure. Note: Be sure to clean and blow dry all pushrods.

Also, blow through the pushrod to remove any foreign matter such as sludge. Remember, in any type of
motor work, cleanliness is imperative.

2. Inspect rocker arm studs, stud bosses, guide plates, etc. for excessive wear. Check to see if the old rocker was

cutting into the side of the rocker arm stud. Also check the guide slots in the cylinder head or guide plates for
excessive wear. Wipe clean the tops of all the valves and again inspect each one for wear or mushrooming of the
valve stem.

Movement of metal or galling of the studs, pedestals or valve stems is a sign of excessive wear. Now is the time
to make whatever decisions are necessary. Installing new rocker arms on questionable studs or mushroomed
valve stems is asking for trouble.

3. Remove the Ultra Pro Magnum™ or Ultra Pro Magnum™ XD Roller Rockers from the package and wash

rockers and polylocks thoroughly with denatured alcohol (lacquer thinner). Do not use water or evaporative
cleaners. Then blow dry. Soak the rockers in engine oil or spray with COMP Cams® Valve Train Assembly
Spray (Part #106).

4. Install the pushrods into the motor with both ends coated with a small amount of assembly lube. If the pushrod

has a long hardened tip, make sure it rides properly in the guide plate. If the pushrod has an arrow, be sure to
install it pointed up. It is recommended that all the pushrods be pre-oiled through the pushrod holes. Apply a
small amount of COMP Cams® assembly lube to valve stem tips and rocker arm pushrod seats.

INSTRUCTIONS

2

COMP Cams®

3406 Democrat Rd.
Memphis, TN 38118
Phone: [phone]

Part #151

Revised 7/9/14

Toll Free: 1.800.999.0853
www.compcams.com

5. Install rocker arm on rocker stud. Pay special attention to the pushrod and rocker arm positioning. Be sure that

the pushrods are seated in the lifter and rocker arm seats. Install polylocks loosely on the studs with the set
screws backed off. Do not tighten the polylocks or set screws until you go through the proper sequence of lifter
adjustment. Install the remainder of rockers arms in this manner.

6. After carefully checking to be sure all pushrods are seated in the lifter and rocker arm, it is time for valve lash

adjustment.

7. Adjusting intake valves: We recommend you work with one cylinder at a time. Using the crankshaft dampener

bolt in the snout of the crankshaft, turn the engine over by hand in the direction of its running rotation until the
exhaust pushrod just begins to move upward to open the valve. Stop rotation. The intake lifter is now on the
base circle of the cam and the intake valve is ready to be adjusted.

Hydraulic Lifter Cams and Stud Mount Rockers: Tighten the polylock until all the slack is taken out
of the rocker arm and pushrod. By lightly turning the pushrod with your fingers as you tighten the
polylock, you will discover or feel a point at which there will be slight resistance. At this point, you
have taken all the excess slack out of the pushrod. You are now at what we refer to as zero lash. Turn
the adjusting nut one-half turn more OR follow your specific lifter pre-load instructions. This will give
you the ideal pre-load of the rocker arm, pushrod and lifter. Repeat this procedure for each cylinder and
carefully adjust all intake valves.

Hydraulic Lifter Cams and Pedestal Mount Rockers (PN 1677 & 1678): When installing the rocker
arms, ensure that you are using the proper length pushrod in order to obtain the optimal amount of lifter
pre-load. Lifter pre-load should be between 0.020" and 0.080". If yours is not, your application
requires different length pushrods. In order to measure lifter pre-load, please use the following
procedure.

First, install the pushrods and torque all the rocker arm bolts down in the proper sequence and proper
torque specification. Rotate the engine by hand in the normal direction of engine rotation until both the
exhaust and intake valves have opened and closed completely. Allow a couple of minutes for the lifters
to bleed down.

Using the valve cover gasket surface on the head as a reference point, place a mark on the pushrod. The
smaller, more defined the mark, the more accurate the measurement. Be sure the reference point you
choose for the first mark is easily accessible and easy to duplicate. The pushrod will be marked twice. It
must be measured from the same reference point and angle for the measurement to be accurate.

Loosen the rocker bolts. Leave the rockers on the head so that they will support the pushrods. Be sure
the pushrods are standing free in the lifters and do not have any pre-load. Using the same reference
point, place a second mark on the pushrod. Make sure the angle and reference point are the same as the
first mark. You now have two marks on the pushrod: one with the assembly bolted into place as the
engine will run, and one with the lifter unloaded. The distance between these two points will represent
the amount of lifter pre-load. Again, if yours is not between 0.020" and 0.080" your application

requires either shorter or longer pushrods.

Solid Lifter Cams: Consult cam spec card or cam manufacturer for correct lash specifications. With the

proper feeler gauge between the roller and valve stem, turn the polylock until a slight drag is felt on the
feeler gauge. Hold the polylock with the wrench and then tighten the set screw using a T-handle or
Allen wrench. Repeat this procedure for each cylinder and carefully adjust all intake valves.