COMP Cams 5100 Camshaft Belt Drive System User Manual

#5100 Camshaft Belt Drive System

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.

If there are any questions or problems during the installation, please do not hesitate to contact the toll
free CAM HELP® line at 1-800-999-0853, 7 a.m. to 8 p.m. CST Monday through Friday.

Belt Drive System Preparation and Installation
Step 1: Install the camshaft gear on an old cam, and carefully rotate it into the engine block. Rotate the

camshaft by hand, and note where the gear contacts the block.

Step 2: The front of the engine block above the center oil galley will need to be relieved so that the
edges of the cam gear do not rub the block. It may also be necessary to relieve an area around the 3
o’clock position of the cam tunnel at the edge of the camshaft gear. Grind these areas until you can
rotate the cam freely in the block without the cam gear rubbing.

Step 3: Bear in mind that the camshaft thrust washer is .150" thick, and that any area where the gear
just barely rubs should not need clearancing. With the thrust washer installed at final assembly, the
cam should rotate freely with no rubbing or binding between the engine block and camshaft gear.

Step 4: Before installation, the rear belt guard must be installed on the crankshaft gear. It has a radius
at the back of the gear that should clear all aftermarket crankshafts. It is common to have the bolts tight
in the belt guard itself. A tap or drill can be used to open the holes a bit. We recommend using anti­seize or a high temperature lubricant on the gear and pushing it onto the crankshaft with a bolt and
sleeve, such as COMP Cams® Part #4920 and #4789. Warming the gear up with hot water will also
aid installation. The crankshaft gear is correctly installed when it is fully seated against the crankshaft
snout. Under no circumstances should a punch or any other tool be used to drive the gear onto

the crankshaft, as doing so will damage the crankshaft gear and crankshaft main bearing thrust
surface.

Step 5: Lubricate the thrust washer on both sides, install it on the camshaft, and bolt on the camshaft

gear using a 0° cam bushing and the stainless steel retainer plate furnished. Carefully feed the camshaft
into the block until the gear and thrust washer are fully seated. Hold a straight edge against the faces of
both the camshaft and the crankshaft gears. Ideally, the two gears should be no more than .025” out of
alignment with one another. If necessary, the rear surface of the crankshaft gear may be machined in
order to improve gear face alignment. Although every effort has been made to ensure that gear
alignment will be within specification, the wide variation between engine blocks makes alignment
verification a necessary step.

3406 Democrat Rd.

Memphis, TN 38118

Phone: [phone] Fax: [phone]

www.compcams.com

:

COMP Cams®

INSTRUCTIONS

Part #131

Revised 5/10/11

Drive Belt Installation Tip: Do not bend, twist or crease the camshaft drive belt, as this will damage
the belt fibers, potentially leading to belt failure. The camshaft drive belt is non-directional and can be
installed in either direction; however, if the belt is removed for any reason, it should be reinstalled to
run in the same direction as it did originally. An easy way to ensure that the belt is always installed
with the same direction of rotation is to install it so that the writing on the belt can be read when
viewed from in front of the engine.

Step 6: Loosen the camshaft bolts just enough to allow the cam gear to be moved slightly. This will
make it easier to slip the belt onto the crank and cam gears.

Step 7: Align the timing marks, lubricate the belt and gears with oil, and push the belt evenly onto
both the top and bottom gears. If installation by hand proves too difficult, a smooth object may be used
to aid in pushing the belt into position.

Step 8: After the belt has been partially fitted onto the two gears, the engine may be rotated by hand to
aid in sliding the belt into position. At this point, the cam bolts should be tightened, but do not secure
them with Loctite® or safety wire. Note: Never use the starter to turn the engine while installing

the drive belt.
Step 9: Degree the camshaft in the same manner that you would with a conventional timing set. See

COMP Cams® Camshaft Installation & Degreeing Instructions, Part #145 for explicit camshaft
degreeing instructions. COMP Cams® instructional DVD, Part #190DVD: “The Proper Procedure to
Install & Degree a Camshaft” is also available. Six camshaft degreeing bushings are provided with
your new belt drive kit to allow from 0 to 5 degrees of advance or retard in 1° increments. When
advancing the camshaft, install the bushing with the number at the top. When retarding the camshaft,
install the bushing with the number at the bottom.

Step 10: After degreeing the camshaft, remove the camshaft retaining plate. Install the roller thrust
button behind the cam retainer plate with no shims at this time.

Step 11: Tighten the camshaft bolts and install the front timing cover with the timing cover gasket in
place. Check camshaft end play with a dial indicator (COMP Part #4909) and set to .001" - .005" with
the shims furnished in the kit. The thrust button furnished is designed to work with COMP Part #210
billet aluminum timing cover or late style GM flat timing covers. Caution should be used when
checking camshaft end play with a stock timing cover, as a stamped steel cover may flex and render an
incorrect end play reading.

Step 12: Rotate the crankshaft and verify that you have adequate belt and gear clearance at all points.
The belt guards will ensure that the belt runs true and does not move in either direction. It is the
responsibility of the installing mechanic to thoroughly check for any belt or gear clearance problems.

Step 13: This is the final installation step. The 6-32 x 3/8"outer belt guard screws should be tightened
with a hex wrench after placing a small drop of Loctite® on the threads. Replacement screws are easily
obtained at any well stocked hardware store and should be changed after every rebuild.

COMP Cams®

3406 Democrat Rd.

Memphis, TN 38118

Phone: [phone] Fax: [phone]

www.compcams.com

Part #131

Revised 5/10/11