Delco EST Ignition System


The initial timing connector is used in setting the initial engine timing on Delco EST ignition equipped engines. This connector by-passes the electronic spark timing of the engine and allows the initial timing to be adjusted by rotating the distributor. Use the following procedure (become familiar with entire procedure before beginning):

The ignition timing marks are located on the engine's front cover. A saw slot on the balancer indicates engine at (TDC) Top Dead Center. Adjust ignition timing as follows:

1.   Connect a timing light to the number one (1) spark plug wire. Connect the timing light power lead to a 12 volt power source. (Do NOT CONNECT TO 12 VOLTS ON ALTERNATOR.)

2.   Start engine and allow to warm to operating temperature. Bring engine to idle (650-800 Rpm).

3.   WHILE ENGINE IS RUNNING, install the  initial timing connector supplied with your  engine into the (4) terminal connector on distributor.

4.   Loosen distributor clamp just enough to rotate distributor in place.

5.   Secure the bare wire and of the initial  timing connector to battery positive "+ voltage. (the most convenient location of this voltage is on the cranking motor solenoid.) If desired, a suitable clip, such as an alligator clip may be permanently attached to the bare wire end of the initial timing connector to hold it in place. While the lead is touching the voltage source, the frozen electronic timing is "Frozen".

6.    Attach timing light according to the manufacturers' instructions.

7.    Rotate distributor to set mechanical timing.

8.    Tighten distributor clamp to hold in position when initial timing is obtained.

9.    Recheck timing.

10.   Detach initial timing connector from distributor.

11.   Check total timing. This must not exceed 24 degrees at 4000 RPM for 181/262 CID engines, 26 degrees for 305/350 CID  engines and 30 degrees for 454/502 CID engines. (see note below)

12.   Disconnect and remove timing light.


CID       @ 500 RPM                @ 4000 RPM

181            0o                                     24o
250            10o                                   32o
262            2o                                     24o
305            8o                                      26o
350            8o                                     25o
454            12o                                   30o
552            12o                                   30o
Warning: These timing Numbers should be verified with your owners manual. These are not necessarily true for every engine setup, and variances can occur. Use these as a reference base only.

Delco EST


MSTS type jumper

EST type jumper and
Tach/power hookup

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