Torque peak vs. HP

[lotusman1951]

When repowering last winter with an eye towards longevity and economy-I avoided Deeres warrenty insistance of proping to 2500rpm at WOT.

The 4045 non-turbo power curve in either Deere of Lugger reveals a peak in the torque curve in the 1200-1400 range of about 220 foot pounds-deminishing as revs increase to about 170 at 2200-2500 rpm.

The HP at 12-1400rpm is 50ish-and 80 at WOT, fuel consumption moves from -1gph to +4gph.

Disreguarding Deeres insistance, maintaining an operating temperture of 180 and oil pressure of 45+--I for one belive that it is torque-not HP that pushes a displacement craft and that prop sizing and transmission ratio balance so that you can operate your vessel in s/l range of 1.1-1.2 works best.

Most "trawlers" in my opinion have way to much HP and*way to small props-Either you tune the boat to the engine or tune the engine to the boat.

Find your torque peak-operate your vessel there by manipulating your running gear-be happy

 

[lotusman1951]

1250 pounds of modded (ex race car) lotus 7 with DSK frame-propelled by a Cosworth YBM 240HP/8500rpm-120 knots plus--the cure for slow boats.

 

[KMA]

Is that the one with adjustable pedals instead of adjustable seats?

LOL... chances are, if it's an ex-race car, it has none of the above.

-- Edited by KMA at 14:33, 2008-10-07

 

[lotusman1951]

Hey I love thing that move--I usually carry a c70/stepthru honda aboard to do runs around bahama islands-tommrow a Derbi 50cc super motard may take its place--the lotus with its alloy skin and tube frame could fit on the front deck--but its not Ok with salt water-only fiberglass things burn to the waterline-thats why I have a steel boat-get smart or get wet..

Boats and lotus cars have 1 thing in common-time and money. Nice to see other like minds out there.