In a 450 hp Internal Combustion engine with 6 cylinders, radiator fan gets power from crankshaft .radiator fan is engine mounted and gets power from crankshaft pulley.radiator fan pulley is mounted with the help of bearing on a housing which is vertically above crank pulley.drive is by BELT.

In the above said arrangemet if i get 30 hp power from crank pulley by adding extra grooves by belt drive ,is my existing fan bearing safe? ( in terms of load carrying capacity).the fan pulley is vertically above crankshaft pulley...if i add one more power drive from crank pulley in horizontal direction what is the bearing load change?

totally 2 belt drives in my system. one from crank pulley to fan pulley and the other from crank pulley to an additional powerconsuming equipment say compressor.

You don't specify, but it sounds as if you've modified an engine to make more power than stock. If the engine redline hasn't changed, then the fan will be drawing the same amount of power that it drew with the engine in stock form. No worries in that case.

If you've raised the engine's redline, then at the higher RPM, the fan will indeed draw more power than it did stock. The load on the belt, and hence the load on the bearing, will both be higher. Unless you also modify the fan bearing so that it is larger, you can probably expect the bearing to wear out faster than it did before. Probably the easiest solution is to install a larger fan pulley or a smaller crankshaft pulley, so that, at the new higher redline, the fan is turning at the original, stock, RPM. Of course, the trade-off is that, at idle, the fan will be turning more slowly than before, and cooling may be compromized. A solution from the muscle-car days is to install a "flex fan", whose blades flex and limit the fan's power consumption.