The odd cylinders are on the left side and the even cylinders are on the right side as the engine sits in the airplane. Cylinders 1 and 2 are the ones closest to the pilot.
The nameplate shown in the first picture I posted shows the cylinder numbering as well as the firing order.
Each bank of four cylinders had the classic four cylinder 1-2-4-3 firing order except on the left bank they are numbered 1-3-5-7 and on the right bank they are numbered 2-4-6-8. The left bank pistons are at TDC 90 degrees before the corresponding right bank pistons and the right bank follows the left bank firing order 90 degrees later.
This results in a regular 90 degree firing interval just like the conventional cross plane crank V-8 engines have. Four power strokes per revolution, one every quarter turn of the crank.