Alco engines are a horse of a different color. They are four stroke cycle engine, as compared to EMD's two cycle. Only half of the given amount of cylinders fire on one rotation of the crankshaft on a four stroke as opposed to all cyilnders firing on one rotation of the crank shaft of a two cycle engine.
It has been many years since I have worked on either a 244 or 251, but if I remember correctly, the engine fired as if it was a big in-line six.
Unlike EMD, Alco (and GE as well) number the cylinders by bank side and number... in other words, #1L,-1R,-2L,-2R,-3L,-3R etc. L meaning Left bank, R being Right bank. The way I remember is that they fired the Left and Right banks only a few crankshaft degrees apart, like I said a big six cylinder engine. So, it would be something like, but maybe not exactly... fires #1 Right, crank rotates a few degrees then fires #1 Left, rotates, fires #6R,6L,- 5R-5L 4R-4L-3R-3L 2R-2L. or close to that. That's what gave the Alco engine it's unique sound. If I am wrong, I am sure I will be corrected but remember it's been over fifteen years since i have been around these thing on a daily basis. One interesting thing is that the firing order on the new 6,000 hp EMD 265H four cycle engine is the same as the 16-710.
Paul
"We are all here because we are not all there."