Re: Wandering K28s/K27 info

Chris:
I don't have a drawing showing overall width, but the drawing I do have shows a K27 with outward canting valve chests is about 8 1/2" wider across the valves than an inward canting valve chests. The outward canting valve chests make a K27 wider than a 480 but a 1/2" or so.
I have a drawing dated from 6/23 showing a inboard piston valve K27 with Stevenson Valve gear. The inboard valve chest lines up with the existing valve rod. This would have made a logical interim locomotive between the old soak slide valve and modern superheated piston valve, Walschert gear engine.
According to Mr. O'berry's Mudhen book, the 454.456.458 & 461 were the first piston valve conversions in 1923/25- keeping the Stevenson gear and saturated steam. According to the AFE records I have which oddly covers installation of flange oilers in 1919 and compound air pumps in 1924, but ignores the first inboard piston valve conversions, shows the first outboard piston valve conversions were 464 and 452 in the latter half of 1925. These engines had Walschert valve gear applied. They were not superheated until a few years later. Later conversions did the superheating at the same time. The inboard pistons valves were given Walschert gear and superheaters in 1926-28, so they only ran as piston valve, Stevenson gear soaks for a year or two (which is probably why no one took a picture of one). Wierdly enough, the last piston valve/Walschert gear conversion was 462 in 1929, which they didn't bother to superheat.