User guide

COMP Cams®
3406 Democrat Rd.
Memphis, TN 38118
Phone: [phone] Fax: [phone]
www.compcams.com
Part #117
Revised 4/17/12
Gear Drive System Part #4100, #4110 and #4136
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.
Notes:
1. The installation procedures which follow assume that the engine has been disassembled and
cleaned as it would be for a normal timing set change.
2. The reverse idler gear should have between .005 and .070 in vertical travel when the set is
installed on the engine with the power idler in hard mesh between the crank and cam gears. If
this is not the case excessive, heat can be generated causing damage to the gear set.
3. The purpose of the reverse idler gear is to prevent the power idler from disengaging when the
crankshaft rotates backwards as happens in shutting off the engine.
4. The engine is timed with the timing marks facing one another just as you would with a chain
and sprocket drive.
5. If a factory timing cover is not used some minor machining to the timing cover may be needed
for use with this set.
6. Idler pins will always be in contact with the timing cover during use. Back of idler pins must
have a minimum of .015 clearance to block.
7. The Dual Idler Gear Drive is intended for use with a harmonic balancer. It is not for use with
an aluminum hub.
Installation Instructions:
1. First, place the bronze wear ring on the counterbore side of the camshaft gear. A small
amount of grease will keep the ring in place during installation of cam gear.
2. Install the camshaft gear on the camshaft and torque to factory specs.
3. Install the crankshaft gear on the crankshaft using the desired keyway. The rounded
keyway is for standard camshaft timing. The triangle shaped keyway is for 4-degree
camshaft advance while the flat topped keyway is for 4-degree camshaft retard.
INSTRUCTIONS