G3406 Engine Caterpillar

Setting the Timing of the Digital Ignition System

Illustration 1	g00761355
Front view and side view of the 163-6164 Timing Control (1) "APPLICATION SWITCH" (2) "TIMING SWITCH"

The timing control has an "APPLICATION SWITCH" (1) and a "TIMING SWITCH" (2). The "APPLICATION SWITCH" must be set to the engine model that is controlled. The switch must also be set to the timing range that is appropriate for the fuel that is consumed. The "TIMING SWITCH" is used to fine tune the ignition timing. Use the following procedure to set the ignition timing.

1. Determine the correct ignition timing for the fuel.

   1. Obtain a fuel analysis.

   2. Enter the data from the fuel analysis into the Caterpillar Software, LERW4485, "Gas Engine Rating Pro (GERP)".

   3. Refer to Engine Performance, LEBQ6483, "G3400 Industrial", "Fuel Usage Guide" or Engine Performance, LEBQ6483, "G3400 Generator Set", "Fuel Usage Guide" or consult with your Caterpillar dealer in order to determine the desired ignition timing.
   Show/hide table

   NOTICE
   Do not change the setting of the "APPLICATION" switch during engine operation. An engine shutdown can occur and/or the engine can be damaged. Always shut the engine OFF before you change the setting of the "APPLICATION" switch.

2. Use the label for the "APPLICATION SWITCH" to choose the correct position for the switch. Set the switch at the lowest possible range for the desired timing.

   Table 1 is an example of the settings that are listed on the label for the "APPLICATION SWITCH".

   Show/hide table

   Table 1

   Settings of the Application Switch
   A = G3304	10 to 25 degrees BTC
   B = G3306/ G3406	10 to 25 degrees BTC
   C = G3408	10 to 25 degrees BTC
   D = G3304	20 to 35 degrees BTC
   E = G3306/ G3406	20 to 35 degrees BTC
   F = G3408	20 to 35 degrees BTC

   Recommendations for setting the "APPLICATION SWITCH"

   For G3406 Engines, the "APPLICATION SWITCH" must be set to "B" or "E".

   For a G3406 Engine with a desired ignition timing of 19 degrees BTC or less, the switch must be set to "B".

   A G3406 Engine may have a desired ignition timing between 20 to 25 degrees BTC. The "APPLICATION SWITCH" could be set to "B" or "E". However, setting the switch to the lowest possible range for the desired timing is recommended. In this case, set the switch to "B".

   For a G3406 Engine with a desired ignition timing of 26 degrees BTC or more, the switch must be set to "E".

   Show/hide table

   NOTICE
   The "TIMING SWITCH" can be damaged if the switch is turned directly between the "0" position and the "15" position. Do not turn the "TIMING SWITCH" between these positions in either direction.

   Note: The "TIMING SWITCH" is graduated in increments from "0" to "15". The switch is fully advanced at "15". The timing is retarded by one degree per each mark as the switch is moved toward zero.

3. Set the timing switch to 15. Then move the switch to the setting that corresponds with the desired timing.

   Examples for setting the "TIMING SWITCH"

   A G3406 Engine has a desired ignition timing of 19 degrees BTC. The "APPLICATION SWITCH" is set to "B" (10 to 25 degrees BTC). A "TIMING SWITCH" setting of "15" corresponds to a desired timing of 25 degrees BTC. Move the "TIMING SWITCH" for 6 positions toward "0". This corresponds with a desired timing of 19 degrees BTC.

   A G3406 Engine has a desired ignition timing of 23 degrees BTC. The "APPLICATION SWITCH" is set to "B" (10 to 25 degrees BTC). A "TIMING SWITCH" setting of "15" corresponds to a desired timing of 25 degrees BTC. Move the "TIMING SWITCH" for 2 positions toward "0". This corresponds with a desired timing of 23 degrees BTC.

   A G3406 Engine has a desired ignition timing of 26 degrees BTC. The "APPLICATION SWITCH" is set to "E" (20 to 35 degrees BTC). A "TIMING SWITCH" setting of "15" corresponds to a desired timing of 35 degrees BTC. Move the "TIMING SWITCH" for 9 positions toward "0". This corresponds with a desired timing of 26 degrees BTC.

   Note: Do not check the timing at low idle speed.

4. Start the engine. Operate the engine at rated speed. Verify the ignition timing with a timing light.

   Adjust the "TIMING SWITCH", if necessary. This is a small adjustment of only one or two positions in either direction. Adjust the switch in order to maintain the correct timing within 1/2 degree.

   Show/hide table

   Illustration 2	g00762284
   (3) Two 176-7375 Switch Caps (4) 5P-1275 Lockwire (5) 8S-8158 Wire Seal

5. Install caps (3) for the switches. Thread lockwire (4) through the holes in both caps. Secure the lockwires with wire seal (5).

   This will help prevent unauthorized tampering of the setting for the ignition timing.