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Torque consideration

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When you think of putting a motor in a tractor that is other than original do you give any consideration to the torque of the new motor ? Another words if you were to replace and older motor say 12 hp with a newer one say 16hp. Do you just look at the hp and say more is better or do you look at the torque to make sure it will be ok for plowing, tillling ect. ? thnx for any comments Herm

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The more torque you have the better. Pulling power is measured more in torque than HP. The weak link in the power train on a large frame tractor is the BGB. The same BGB has been used from 7hp to 20hp in these tractors. The large frame tractor with the most torque is the Simplicity 7790 diesel and Allis Chalmers 920D diesel. I have a 7790 bought new in 1985. This tractor is going on 20 years old with no problem with the BGB.(I did have to replace a worn axle tube and seals) This tractor has been used and abused. It's main job was blowing snow in 3 commercial parking lots and 5 or 6 home driveways. It has pushed /pulled cars into my garage some with locked wheels. I have also pulled a 32" camper and my GMC K3500 4x4 tilt bed truck that weighed 9000lbs empty with it. My biggest problem was loosing traction. The tractor has 12/10.50/23 ag tires loaded with chloride, 50lb wheel weights and V bar ice chains. Total wheel weight aprox. 150lbs per wheel. The bottom line is if your BGB is in good condition and you service and maintain your tractor you should not have problems.

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Speaking from the experience I have with large farm tractors, and the "need" for some guys to turn the pumps up on the diesels to get more power from them - it's ok to have more power, you simply need to use common sense with how you're going to use that power. If you replace that 12 hp with a 16 hp and then weight the arse end down, add chains and duals with chains, and then use a dozer blade to move piles of dirt that would make a D8 Cat grunt, you're gonna have problems! Basicly, don't try to do more than what you could do with only 12 hp under the hood. Anything that is driven strictly by belts off the engine itself (snowblower, mower deck, etc) - you can go larger with. But as UCD mentioned, any power that has to go through the gear box or tranny must be limited to what that gear box is designed for. Good luck! Tom

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