AEM 23-831BK Tru-Time Adjustable Cam Gear - Manual (Page 7)

constant engine RPM in second gear (both for manual and automatic transmission) and
then accelerate to the vehicle redline while recording the time it takes to reach redline.
We perform this test at least 3 times to establish an average reference point. Notice that
there is no shifting or tire burning (if you do have a traction problem, use a higher gear)
in this procedure. Using this procedure will give reliable and repeatable data.
(b) As outlined at the preface of these instructions adjustments to the cam timing must be
done with a very conservative approach. Excessive movement of the cams during
adjustment increases the likelihood that the pistons and valves will touch.
(c) All testing should be done on a chassis dynamometer or at the test track. Under no
circumstance should you resort to testing on public roads.
(d) For early Mitsubishis equipped with a cam driven distributor.
i) Verify that the ignition timing is correct (use a timing light to do this, do not guess).
The ignition timing must be verified EACH time the cam timing is changed because
the cam drives the distributor. Any change to the cam timing will affect the
ignition timing.
ii) To change the cam timing, loosen the three retaining bolts (figure 1) in the slotted
holes in the inner hub. Rotate the cam to the desired position and retighten the three
retaining bolts to 15-ft. lbs. If the head is milled, then retarding the exhaust cam lobe
timing must be carried out with extreme care. You must have at least .060” between
the piston and the valve.
(e) After the cam timing change is made, re set your ignition timing and go out and try your
acceleration test or perform dyno testing. You must check your fuel calibration after
each cam timing change in order to perform an accurate test. The cam timing has a
profound effect of the air/fuel mixture and if it is not optimized for each cam timing
setting you will not know if the effect of the change in cam timing is positive or negative.
(f) When you have concluded testing, re check the cam bolts for tightness, apply Loctite
®
“red” to the three retaining bolts, re install the cam belt cover and know that you
have installed the best cam timing sprocket(s) available.
Caution: Cam adjusting bolts loose. Tighten before starting engine.
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