Horsepower ratings

What was the difference between the (new) M's rated at sea level and those rated for 5000 ft? Thanks. Could find nothing in the archives.

I guess I don't understand your question. The 5000 ft option had higher compression to compensate for the higher elevation.

If you take an M with it's rated H.P. at sea level, standard atmosphere & pressure and could simulate going to 5000' altitude with ALL else being the same (i.e. that same tractor could suddenly be lifted up 5000' in elevation at that same spot), you'd loose about 14% power. Not having the tractor data at hand but assuming about 34 H.P. at sea level, the M would have about 29.25 H.P.
Is this what you were wondering? I think it's probably more along the lines of the Nebraska Cowman's statement or the difference in the altitude package verses standard equipment M that you are wanting. Someone I'm sure has that on this forum.
Later, John

(quoted from post at 13:58:20 12/18/11) If you take an M with it's rated H.P. at sea level, standard atmosphere & pressure and could simulate going to 5000' altitude with ALL else being the same (i.e. that same tractor could suddenly be lifted up 5000' in elevation at that same spot), you'd loose about 14% power. Not having the tractor data at hand but assuming about 34 H.P. at sea level, the M would have about 29.25 H.P.
Is this what you were wondering? I think it's probably more along the lines of the Nebraska Cowman's statement or the difference in the altitude package verses standard equipment M that you are wanting. Someone I'm sure has that on this forum.
Later, John

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So you're thinking that a 5,000 ft. altitude equipped M, even though it still makes only 36 horsepower at that 5,000 ft. altitude, would make 14% MORE horsepower at sea level than the standard engine equipped M which is also factory rated at 36 horsepower? 14% x36 is approximarely 41 horsepower, or 5 horsepower more.

Is this correct? At sea level the higher compression tractor would generate 14% more hp than the standard, however, if you took the higher compression tractor to 5000 ft., its hp would be approximately the same as the standard compression tractor at sea level. I live at 3300 ft., so assume the high compression engine would generate about 4 to 5% more power. Thanks to all for enlightening a dim bulb!!

Except that at sea level you might have to use higher octane fuel to avoid knocking at sea level in the higher compression engine. Otherwise they would have built them all high compression. Farmers wanted to be able to use the cheaper grades of fuel.

(quoted from post at 15:01:15 12/18/11) Is this correct? At sea level the higher compression tractor would generate 14% more hp than the standard, however, if you took the higher compression tractor to 5000 ft., its hp would be approximately the same as the standard compression tractor at sea level. I live at 3300 ft., so assume the high compression engine would generate about 4 to 5% more power. Thanks to all for enlightening a dim bulb!!

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No, the the above summary is not completely accurate. 1) Since the air is less dense at 5000 ft, the compression ratio can be increased to regain some of the power which is lost due to the reduced air density. However, the tractor's HP will still be less than it's counter part operating at sea level. 2) At sea level the higher compression tractor will make more HP than the standard compression counter part however I would expect the difference to be more in the range of 5% rather than 14%. To increase power by 14% would require a drastic increase in compression ratio. 3) As noted by another poster higher octane fuel may be required when operating the high compression tractor at sea level due to the increased air density as compared to 5000 ft.

Hope this helps