Belt driven loads - 'balancing' needed?

[danielb]

Hi,
I recently removed my fridge compressor in favour of a DC system.
Now I have two belts left: the fresh water cooling pump, and alternator on one, and the added-on water pump">raw water pump on the other.
They both 'pull' roughly the same direction off the crank shaft pulley.
Does this matter in terms of the front bearing? Should I relocate the the raw water pump to the opposite side?
Or are the loads negligible compared to the pistons firing etc?
Engine is a 3 cylinder Daihatsu 26.5hp 950cc diesel.

Regards,
Dan

[DougR]

Hi Dan,
The best way to answer your question is to go to the engine manufacturer or distributor and ask what the front end PTO limits are. Then you will know the answer to your question. Of course that's easy to say but sometimes difficult to actually do.

Most engines have limitations to: 1. the amount of power that can be pulled from the front end 2. The direction of pull 3. The amount of pulley overhang allowed.
This is normally expressed in a diagram that looks sort of similar to a sailing polar diagram. Theses diagrams typically show that lower h.p. engines are more sensitive to power and pull direction than larger engines, so it is something that you should be aware of.

In the event that you can't find any definitive information, probably the safest thing to do is to move the raw water pump and balance the loads.

DougR

[LakeSuperior]

Over tightening belts also reduces the bearing life on the water pumps and alternators for example. I try to error on the side of less belt tension.