|IH fan said: (quoted from post at 16:54:24 12/02/12) |
Go to the Nebraska tests and look at the drawbar bull as compared to the drawbar HP... there seems to be no direct correlation. I believe the pull weight means more than the Hp rating. I imagine the pull weight takes into consideration the weight, gear ratios and maybe other things. Ford tractors were geared pretty high and with a 4 speed, ratios were spread more. IH Ms and Hs had a 5 speed, JD B, A and Gs and Olivers had 6 speeds ... these things all entered into how they pulled, as well as the torque rating.[/quote:51dcee83d3]
Horsepower is the product of the actual force the tractor is exerting on the drawbar times the speed in which it is being pulled. A tractor can actually pull a greater load at a lower speed and produce less horsepower than if it pulled a smaller load at a faster speed.
For example, in tractor test #328 the Farmall M gas tractor produced a 100% maximum drawbar horsepower of 33.05 while exerting a drawbar pull of 4060 pounds and traveling 3.05 mph. Yet it produced a maximum 4233 lbs. pull on the drawbar while traveling 2.17 mph and produced 24.49 horespower.
[quote:51dcee83d3="mattwillson"](quoted from post at 19:25:12 12/02/12) my M dyno'd 42 hp last summer at SWOSTA. this year, with the turbo, it should touch 80+.
248ci, pretty much worn out. 1950 model yr
Do you know for sure your engine is 248ci? Reason I ask is because the M engine came from the IHC factory with a 3.875" bore and cast iron pistons. Most Ms have since been rebuilt with thinner sleeves and 4" aluminum pistons which will give an increase in horsepower. As a matter of fact, ALL new piston/sleeve kits made for the Farmall M today will have 4" aluminum pistons. Also, a lot of the 4" pistons are domed to increase compression and that will increase horsepower too. So, with the 4" pistons you have 264 CID and essentially a Super M engine. This post was edited by Nebraska Kirk at 17:49:30 12/02/12.