ENGINE AND ENGINE REBUILDING 67
PIN
WASHER
Exploded view of the HEI distributor. Engines with the computer emissions system do not have the vacuum
advance unit.
travel (top dead center -TDC) in order to time
the ignition system to the engine. There are
several ways to determine when the piston is
on its compression stroke. In any case, the
#1 spark plug must be removed. The various
methods are as follows:
a. Hold your finger over the spark plug
hole and have an assistant turn the engine
over slowly. When you feel compression,
watch the timing marks. Stop turning the
engine over as soon as the timing mark on
the crankshaft balancer is aligned with the
"0" mark on the timing tab scale.
b. Insert a rag into the spark plug hole
(NOT into the cylinder). Turn the engine
over slowly until the rag is blown out of the
hole. Stop cranking the engine when this
happens and check the riming marks. If
necessary, "tap" the ignition key until the
timing mark on the crankshaft balancer is
aligned with the "O" mark on the timing
tab scale.
c. Attach a compression gauge to the
spark plug hole (preferably the screw-in
type; eliminating the need for an assistant).
Position the gauge dial so that it may be
viewed while cranking the engine. Turn the
engine over until the gauge needle reading
increases, indicating compression. Stop
cranking the engine when this happens and
check the timing marks. If necessary, "tap"
the ignition key until the timing mark on
the crankshaft balancer is aligned with the
"O" mark on the timing tab scale. Remove
the compression gauge. NOTE:
There are
tools available commercially which screw
into the #1 spark plug hole and register
(more accurately than the above methods)
when top dead center is reached. If one of
these tools is used, follow the tool
manufacturers instructions.
2. Reinstall the #1 spark plug and connect
the plug wire. With the distributor out of the
vehicle and the distributor cap installed, lo
cate the #1 distributor cap terminal and chalk
mark its position on the distributor housing.
Remove the distributor cap.
3. Position the distributor into the engine
block with the:
a. vacuum advance unit in its proper
position (see the Firing Order illustra
tions).
b. firing tip of the rotor pointing to the
mark made during step 2.
4. As the distributor drive gear engages,
the rotor will turn slightly. If the distributor
CIRCLIP
COVER
POLE PIECE
LEAD WIRE
AMPLIFIER MODULE
CAPACITOR
VACUUM CONTROL UNIT
HOUSING
ADVANCE SPRING
GASKET
CONNECTOR
GEAR'
