By Chris Wantuck
Even though your engine may be antique, that doesn't mean it can't be a great performer. Good engine performance is accomplished, among other things, by good valve timing, proper carburetor mixture, and accurate ignition timing.
Several auto manufacturers from the early years up through the 1950's used a dual point ignition system. A DELCO dual point system is just one example and was used on the model L Lincoln. This version has two coils, two condensers, two sets of points and even the rotor and distributor cap have separate contacts for the two ignition systems. The two ignitions are divided equally each firing the right block (Passenger side, cylinders 1, 3, 7 and 5), and the left block (Driver's side, cylinders 6, 8, 4, and 2)
Photo 1 — Top view of the distributor and the cylinder numbering. Note that if the rotor is adjusted clockwise then the timing would be retarded.
Manufacturers like Lincoln outlined a timing procedure in their Owners and Service Manuals that uses the ammeter and rotating the crankshaft to reflect the point when the breaker points have opened on each of the two ignitions (aka the continuity method).
The continuity method is good for a rough adjustment to get the car started, but rather than relying on this tedious procedure for accuracy, we suggest a more convenient and accurate method using a timing light to verify or adjust your dual point ignition timing.
As shown in the before and after pictures, there was a very noticeable difference in engine performance when the timing was set using a timing light versus continuity.
Note: The following steps were applied to a Lincoln, and assumes that the car has distributor plates that are adjustable. However you should be able to adapt them to your specific auto. Keep in mind that some early cars had both sets of points fixed in position. Setting the left bank relative to the right was done by bending the point arm or adjusting the point gap. Familiarize yourself with your specific ignition system and know how to make the necessary adjustments. The article also assumes that the ignition advance system (as applicable) is assembled correctly and operates smoothly.
Photo 2 — View of the bell crank and control rod linkage used on the model L Lincoln advance. Make sure the bell crank is mounted correctly with the shorter arm connected to the distributor and the longer arm to the gear at the base of the steering wheel. Verify the distributor advance linkage moves freely and through its full travel.
Step 1 — Familiar yourself with the flywheel timing marks on the clutch ring as shown on Photo 3 by reviewing the literature of your specific ignition system. Note where certain marks are located and the ones adjacent to them. Note the marks before them to reaffirm when relevant timing marks (R1 & R2 in this case) should be coming into view.
Photo 3 — Diagram of the timing marks shown on a clutch ring gear for a model L Lincoln. The location and marking legend for your ignition will be different.