AEM 23-804BK Tru-Time Adjustable Cam Gear User Manual

TRU-TIME

ADJUSTABLE

CAM GEAR

Part Number:

23-800BK & 23-804BK

WARNING:

This installation is not for the mechanically challenged! If you
are not mechanically inclined or do not understand the
procedure please do not attempt the installation. Refer the

installation to a reputable mechanic. It is highly recommended to

,!

Legal in California only for racing vehicles which may never be used upon a
public highway.

purchase the factory service manual to use as a guide along with
these instruction sheets

.

©2011 Advanced Engine Management, Inc.

AEM Performance Electronics

th

2205 W. 126

Phone: [phone] Fax: [phone]

Street, Unit A, Hawthorne, CA 90250

http://www.aemelectronics.com

Instruction Part Number: 10-7030 Rev C

You have just purchased the BEST adjustable cam sprockets available. These AEM billet
aluminum adjustable cam gears are CNC machined from billet aluminum and then laser etched
with cam timing marks for adjustment up to ±10° at the cam or ±20° at the crankshaft. Using the
vernier scale on the sprocket hub helps to do the cam timing changes quickly and accurately.
The inner hub is anodized for lasting beauty and resistance to corrosion. The out gear sector is
hard anodized for resistance to wear.

We have found that there are significant power gains to be made by adjusting the cam timing
even with stock cams and compression. Adjustable cam sprockets are usually required in
applications where an aftermarket or reground performance cams are installed or the cylinder
head has been milled 0.005” or more. The use of these cam sprockets allows the extraction of
maximum power from your engine. We have recorded gains of up to 10~15 horsepower due to
cam timing tuning using adjustable cam sprockets.

When an aftermarket or reground cam is installed, the original manufacturer’s cam timing
specifications are no longer accurate. The adjustable cam sprocket allows you to make
necessary adjustments to cam timing to maximize the performance of your engine. This is
accomplished by “degreeing in” the optimum cam timing for a particular engine set up.

The adjustable cam gear is especially effective when used with heads that have been milled.
The adjustability of the gear allows the accommodation of the changes in cam timing due to the
variation of timing belt length from the bottom gear to the top gear when the head is milled. If the
head has been milled 0.005” or greater the relationship between the head and the block is
altered by moving the head closer to the crankshaft resulting in retarded cam timing.

It must be emphasized that the preceding descriptions are generalizations and any adjustments
made must be done with a conservative approach and on a dynamometer or on a racetrack. We
do not condone any illegal activity on the street.

Part Number: 23-800

Quanity Part Number Description

5 1-2037 Bolt, 5/16 x 1/2
5 1-304 Washer, SS 5/16 x .570 x 1/32
1 10-7030 Instructions, 23-600 & 23-604
2 10-922S Decal, AEM Large Silver
1 2-810BK Inner Hub, Honda
1 2-801HA Outer Gear
1 90741-657-000 Key, Honda Cam

Part Number: 23-804

Quanity Part Number Description

5 1-2037 Bolt, 5/16 x 1/2
5 1-304 Washer, SS 5/16 x .570 x 1/32
1 10-7030 Instructions, 23-600 & 23-604
2 10-922S Decal, AEM Large Silver
1 2-804 Inner Hub, Honda
1 2-801HA Outer Gear
1 90741-657-000 Key, Honda Cam

Getting started

a) The procedure to change the gears is similar to the timing belt replacement procedure outlined in

the factory service manual.

i) Note: This would be an appropriate time to replace the timing belt if replacement is

due or is close to the replacement interval.

b) Obtain a suitable box or container to hold the hardware that will be removed from the engine

during this installation. This will aid in the prevention of lost nuts and bolts.
c) Disconnect the negative battery terminal before starting these procedures.
d) Raise the front of the vehicle and support on jack stands. To ensure maximum safety use jack

stands that are properly rated for the task.
e) Remove the four nuts securing the driver side wheel and tire. Remove wheel and tire and set

aside.

2) Removal of the stock cam Gear

a) Remove the spark plug wires. Remove the bolts securing
the valve cover to the cylinder head. Remove valve cover.