COMP Cams 5760 Chrysler Hemi Phaser Lock Kit - Manual (Page 2)

COMP Cams®
3406 Democrat Rd.
Memphis, TN 38118
Phone: 901.795.2400
Part #COMP4-156
Revised 1/4/12
Toll Free: 1.800.999.0853
www.compcams.com
Read This Pre-installation Guide Before Installing Kit !!!!!!!
Chrysler 5.7L and 6.4L engine cam phasers, how they work, their limitations, and how COMP
uses them for making more power
What are cam phasers?
Chrysler’s cam phasers are specially designed, computer controlled cam gears that have the ability to
adjust camshaft position while the engine is running. They are used on all 2009 5.7L and 2011 6.4L
newer engines.
How do they work?
Engine oil is pressure fed through a series of passageways in the cylinder heads and camshafts, out to
the cam phasers. The engine computer controls a pair of solenoids that adjust this oil flow into, and out
of, a series of chambers inside the cam gears. Located inside these chambers are vanes, attached to a
spring-loaded central hub. The hub is directly attached to the camshaft, and as oil is allowed into and
out of these chambers, the position of the cam can be retarded up to 38 crankshaft degrees.
Why did Chrysler put them in the engine?
Chrysler’s primary reason for using cam phasers was to increase the engine’s efficiency by reducing its
pumping losses. Basically, when the cams are retarded 15-30 degrees, during part throttle engine
operation, it takes less power to turn the engine over. This helps to increase the engine’s fuel
efficiency, but an additional power benefit is also realized by being able to position the camshaft for
maximum power, regardless of what rpm the engine is running at. This results in an engine that makes
more torque and horsepower and extends the high rpm power-band by an additional 800-1000 rpm.
Why should I modify the cam phasers with COMP’s lock kit?
If there is a downside to the cam phaser as designed by Chrysler, it is that they have such a wide range
of movement. Since the cam can theoretically be retarded by up to 38 degrees, there is very little piston
to valve clearance in the engine. This minimal piston to valve clearance limits us to fairly small cam
profiles with very little overlap; not the best for making maximum power or achieving an aggressive
idle sound.
What does COMP’s cam phaser lock kit do?
COMP’s Cam Phaser Locks is a precision made spacer that installs into the cam gear’s oil chambers.
This spacer takes up all the volume that would normally be used by the factory cam gear for
movement. By installing the cam phaser limiter, the cam design window opens up, allowing you to
install big powerful camshafts with safe piston to valve clearances.
Why can’t I just reprogram the ECU to limit cam phaser movement?
Since Chrysler’s factory engine computer is programmable, the question arises as to why you can’t
simply program in the limits and not bother with mechanically limiting the cam phasers. Theoretically
you could do that, but a problem arises if something happens that would cause the engine’s rpm to shift
faster than the cam phaser controls can react to. For example, if you ever missed a shift, broke a
driveline part, did a clutch dump on a sticky set of slicks, or anything that could for a split second
cause the cam phaser to get out of its programmed limit, the valves could crash into the pistons. By
mechanically limiting the maximum movement of the cam phaser, total engine safety is assured when
running a big performance cam in these engines.