COMP Cams 8959-16 Hydraulic Roller Lifters User Manual

1

COMP Cams®

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

Part #COMP4-140

Revised 3/22/12

Toll Free: 1.800.999.0853
www.compcams.com

INSTRUCTIONS

Hydraulic Roller Lifters

Applicable Part #s: 850-16, 851-16, 853-16, 854-16, 857-16, 900-16, 8920-16, 8921-16, 8931-16,
8934-16, 8953-16, 8954-16, 8957-16, 8959-16

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

The following instructions cover the correct procedures for installing COMP Cams® Hydraulic Roller
Lifters. The hydraulic roller lifters can be used with adjustable and non-adjustable valve train setups.
Through various testing we have discovered that the recommended lifter pre-load should be set 1 turn

of the wrench on the rocker arm adjusting nut past zero lash for optimal performance.

Setting Hydraulic Lifter Pre-load:

The correct amount of lifter pre-load is important to help efficiently control the valve train. Insufficient
pre-load will cause valve train noise, while too much may damage the hydraulics of the lifter or cause
low manifold vacuum. By following the four steps listed below you will help ensure proper engine
performance and reliability.

Instructions:

1. Lifter Preparation: Remove your new COMP Cams® lifters from the packaging, and clean

the lifters thoroughly in mineral spirits or an equivalent solvent. It is not necessary to “pre­pump” hydraulic lifters full of engine oil prior to installation and valve adjustment. It is actually

undesirable to do so as the “pumped up” lifters will cause the valves to open during the
adjustment process, rather than positioning the lifter plunger in its operating position as it is
supposed to do. “Pre-soaking” hydraulic lifters in a bath of engine oil is a good idea, but not
mandatory. Doing so ensures that the lifters are adequately lubricated on their outer surfaces
prior to installation. It may also result in a quieter engine start up as the oil in the bath may
displace some air from the lifter’s plunger reservoir. When you install the lifters, make sure
they fit well. Any excess clearance or tight lifters can cause damage to the camshaft, leading to
engine failure. Note: Contact your engine builder or block manufacturer for your specific

clearances.

2. Setup: With your cam installed, simply place the prepped lifters into the lifter bores. If you are

using hydraulic rollers with a link bar, pay close attention to which direction the link bar faces.
The link bars on retro-fit lifters should face towards the valley of the block (except 8920-16,
link bars must face the cylinder side of the block instead of the valley). If the link bar has
an arrow on it, make sure the arrow is pointing upwards (↑). If your engine block was originally
equipped with hydraulic rollers make sure the lifter roller wheel is positioned to roll along the
camshaft lobe. Failure to do so will result in camshaft damage and improper oiling. Now that
the lifters are in place, you can begin to install the pushrods and rocker arms.

2

COMP Cams®

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

Part #COMP4-140

Revised 3/22/12

Toll Free: 1.800.999.0853
www.compcams.com

3. Pushrod and rocker arms: Clean all pushrods thoroughly because most engines oil through

the center of them. If the original pushrods are being used, be especially sure they come clean
inside and out. Apply a small amount of COMP Cams® Engine Assembly Lube (Part #102) or
an equivalent lube on each end of the pushrods, and install them into the engine. Clean all
rocker arms thoroughly. If the original rocker arms are used, examine each one for excessive
wear, and replace any that are questionable. Apply a small amount of lube on all contact areas
of the rocker arm. With a clean rag or towel, wipe the tips of the valves clean and apply lube to
them where the rocker arms will come in contact with them. Also be sure to check the valve
stem tips for excessive wear. Next, install the rocker arms. Make sure the pushrod is in the lifter
and the rocker arm seat when making valve adjustments.

4. Adjusting pre-load: COMP Cams® Hydraulic Roller Lifters can be used with adjustable and

non-adjustable valve train designs. However, each type of valve train has its own set of
procedures for setting pre-load. This section is divided into two parts: Section I describes
adjusting pre-load with an adjustable valve train, while Section II explains adjusting the valves
using a non-adjustable valve train.

Section I. Setting pre-load with ADJUSTABLE ROCKER ARMS

Turn the engine in the normal direction of rotation. Start with cylinder number one (1). When the
exhaust valve begins to open, adjust the intake valve to the correct pre-load. To reach zero, take the
pushrod between your finger tips and move it up and down while you tighten the rocker arm. Once
you feel the pushrod has no more vertical slack, you are at zero pre-load. Make sure the pushrod is
in the lifter and the rocker arm seat when making valve adjustments. As stated before, the
recommended setting is 1 turn of the wrench on the rocker arm adjusting nut past zero. Now, you
can move on to the exhaust valve on the same cylinder. Begin by rotating the engine over again
until the intake valve reaches maximum lift and is almost all the way back down. Then set exhaust
valve using the same method as the intake (1 turn of the wrench past zero). Continue adjusting the
valves on each cylinder in this manner until all valves are adjusted.

Section II. Setting pre-load with NON-ADJUSTABLE ROCKER ARMS

A different procedure and measurement is required to set hydraulic lifter pre-load on engines with
nonadjustable rocker arms. First, install the pushrods and torque all rocker arm bolts down in the
proper sequence and 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 from the same reference point and angle for the measurement to be
accurate.

Loosen the rocker or rocker shaft 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.