I was over at OSS and a question came up about using a 4 cylinder igniter on a 2 cylinder so i was prompted to map out the firing order / ignition sequence and how TDC/BDC and 1-4 coil and 2-3 coils firing relates to the igniter and it's pickup.
I worked it out based on a 4 cylinder firing order or 1-2-4-3 and a twin firing order where the cylinder are 180 out like a 1-2 pair.
First the timing for the 4 cylinder here. You will see the upper 4 traces represent cylinders 1-4 with TBC and BDC represented across the top. Compression strokes are represented by a thick RED arrow going up. Exhaust strokes are represented by a blue arrow going up.
Each spark pair has a common colored dashed circle.
Light blue is #1 , #4 both compression and lost spark
Orange is #2 #3 both compression and lost spark
The coil that is firing that is shown on the 5th line down. The last line shows which igniter is firing the coils. The rear pickup is R and the front igniter is F (or left and right when you look at the ignition plate respectively).
Just block out the 3-4 cylinder and the 1-2 pair should be how a 180 degree in line 2 cylinder is.
P.S (EDITED ONCE ) if any of this is wrong let me know
I worked it out based on a 4 cylinder firing order or 1-2-4-3 and a twin firing order where the cylinder are 180 out like a 1-2 pair.
First the timing for the 4 cylinder here. You will see the upper 4 traces represent cylinders 1-4 with TBC and BDC represented across the top. Compression strokes are represented by a thick RED arrow going up. Exhaust strokes are represented by a blue arrow going up.
Each spark pair has a common colored dashed circle.
Light blue is #1 , #4 both compression and lost spark
Orange is #2 #3 both compression and lost spark
The coil that is firing that is shown on the 5th line down. The last line shows which igniter is firing the coils. The rear pickup is R and the front igniter is F (or left and right when you look at the ignition plate respectively).
Just block out the 3-4 cylinder and the 1-2 pair should be how a 180 degree in line 2 cylinder is.
P.S (EDITED ONCE ) if any of this is wrong let me know
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