I have a Massey Harris 80 (S.N.201824) and an 80 SP Special Combine (S.N.212421)as well as the operating instructions for both and a parts book that covers both. There are all kinds of differences between the 80 and 80SP, just as in the 750 red cab and grey cab. One significant change was the incorporation of sealed bearings (S.N.204879),which reduced the number of grease points by about 100. The 80 had a pedal speed control, while the 80SP used a lever. The 1955 80SP introduced a drive clutch. On the 80 you had to run the speed control all the way down to disengage the engine from the drive transmission. The returns in the 80 were augured to the cylinder, while in the 80SP they went down a chute from the top of the return elevator. The cleaning shoe on the 80 had all the grain that passed through the chaffer slide down a sloped floor under it to the front of the cleaning sieve before it dropped into the wind again. On the 80SP, grain that fell through the chaffer continued on down to the clean grain sieve unimpeded. The 80SP replaced the conventional table auger fingers with a much more open design of angle iron pieces, which were totally trouble free and worked very well indeed. But I guess farmers preferred what they were used to, and Massey went back to the troublesome enclosed auger fingers. About 30 years ago I converted my 80SP to 12V negative ground, keeping the 6V starter and adding an alternator and 12V coil. This solved the hot engine starting problems. You only had to touch the starter button, and she would go. I ran my 80SP until 2000 (45 years running and stored outside),when everything seemed to go at once: the beater wore through, and the shoe fell apart. I sold the Chrysler flathead engine and the 80SP machine joined the 80 standing outside waiting to be scrapped. I have lots of spare parts (bearing belts etc.) if anyone is interested. My location is 30 miles north of Toronto Ontario, Canada. I rebuilt a red-cab 750, which I'm now running.
