Power Curve....

Dandy Dave · Post by **Dandy Dave** » Fri May 21, 2010 1:43 pm

OK Fellows, At what RPM is our Fordson Major engines most efficient

This would be the point where RPM and rising Torque Meet. Over the curve, and the torque drops. Dandy Dave!

Post by **Brian** » Fri May 21, 2010 5:31 pm

1100 to 1300 RPM Major, 1600 to 1800 on Power and Supers. It works out at PTO speed on most tractors.

Torque will rise to around 1200 rpm then drop.

super6954 · Post by **super6954** » Fri May 21, 2010 7:01 pm

Brian wrote:1100 to 1300 RPM Major, 1600 to 1800 on Power and Supers. It works out at PTO speed on most tractors.

Torque will rise to around 1200 rpm then drop.

Well Brian that is what i was thinking the answer was

. Didn't ford have to alter the revs on the super major tractors as the pto speed was at such low rpms on the older major tractor it was gutless when using pulled pto equipment. ?

Post by **Brian** » Fri May 21, 2010 10:47 pm

Yes, they brought the speed up to around 1800 for PTO speed.

The problem was, not that the tractor had low power but that the gearbox did not allow a good range of forward speeds at PTO revs.

That was the reason for the 4.4 rear axle.

If you go back to Henretta's time, the PTO speed was around 700 RPM which meant that she had to rev at around 1000 to get 540. I broke a number of connecting rods on my Ransomes mower before I remembered this.

Dandy Dave · Post by **Dandy Dave** » Sat May 22, 2010 1:22 pm

PTO Speed would have been my educated guess. Thanks for conferming that. I guess that also with the high PTO that it would change slightly also. The engine speed is about 1600 for 540 on my power major with the high PTO. Dandy Dave!