This is why I'm thinking placing the sensor exactly between cylinders 3 and 1 TDC would be ideal. since there is 60* between their TDCs, placing it halfway would make it 30* BTDC going both directions. Forward would be Trigger-30*-#1TDC. Reverse would be Trigger-30*-#3TDC. This is all assuming a 36-1 wheel on the crank, which wouldn't be hard to do at all since the pulley for the distributor would be removed and provide an easy mount for it.elaw wrote: The important point being that as another poster indicated, if the center of the gap is exactly at TDC, the timing calculation will be the same regardless of which way the engine is turning.
Also, if the sensor is placed that way, all coils would need to be swapped when going in reverse. #3 would be the first to fire after the gap, and #1 would be last.
Forward T-1-6-4-2-5-3-T-1-6-4-2-5-3
Reverse: T-3-5-2-4-6-1-T-3-5-2-4-6-1