[AJD] Two Cylinders and Power Driven Equipment

E. M. THATCHER ethatche at hotmail.com
Sat Feb 9 10:30:04 PST 2008


It's been awhile since I commented on any of the online discussions.  I used to be pretty regular here until about four years ago.  Just retired last month so I have a little more time on my hands although not much as it turns out.  Guess I'm somewhat qualified to comment with over 50 years experience owning and operating two cylinder Deere's and their multi-cylinder counterparts.  From my experience and that of my Dad it seemed to us that power driven equipment performed better behind multi-cylinder tractors than behind the two cylinder Deere's that we owned.  That's not to say combines and pickers didn't work or experience more breakdowns when powered by  a two cylinder Deere but some implements (combines in particular) worked better with other tractors.  The perceived smoother delivery of power may have been a factor although I also agree that the heavy flywheel on the JD's should have effectively cancelled out the two-cylinder pulses.  I attributed the difference to whatever slight gearing advantage the multi-cylinder tractors had in order to achieve the standard 540 rpm 'pto output.  An "A" running at 975 rpm's is not going to have as much gear reduction to achieve the 540 rpm pto speed and therefore mechanical advantage at the pto as an International "M" or Minneapolis Moline "U" running at 1300 rpm's or so.

The same would seem also apply to belt drive equipment.  The Deere was running directly off the end of the crankshaft (model "H" and vertical twins excepted)  while counterparts probably for the most part enjoyed some level of reduction from the engine to the pulley.  Much of that may have been nullified however, by varying pulley diameters to achieve the proper belt speed to drive separators, hammer mills, saws, etc.  Something to think about anyway.  Maybe you guys already have the answer.  What are your thoughts?   

On another note... If I can successfully upload it,  I have a short video originally filmed in 8mm of my Dad combining wheat in 1958 with a 49 JD "A" running a JD 25 combine.  Too bad there isn't any sound.  The "A" powering the Model 25 through a good stand of winter wheat was (and is) a total sensory experience.

Eric Thatcher

St. Peters, MO  



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