underdrive pulley question?
 

I just recently bought some underdrive pulleys and I noticed that the crankshaft pulley was significantly smaller but the water pump pulley was much bigger. Did they do that so that I would be able to use the same belt. Also, will it be better as far as performance to just use my smaller stock water pump pulley, or is it bigger for a reason. Please help me out here. Thanks guys.

This is correct. THe alternator pully is also a different size in order to use the stock belt.

Underdrive pulleys are suppose to slow down the movement of all the accesories, while making the crank shaft spin at the same speed if not more. The larger water pump and alt pulleys slow down their cycle as they spin while the crank pulley is spinning much faster cause of it's smaller diameter pulley. This gives the crank shaft less resistance while the motor is running.

Thanks for the help guys. Should I use the stock water pump or the bigger one that came with the u.d. pulley kit, or will it really affect performance?

I've got two sets of pulleys installed and haven't noticed any problems with the cooling. Both have stock water pumps. One with a 3 row radiator, the other a stock two row.

What about charging problems? Did you experience any of that or do you have a 3G alternator?
Is there a difference that you can actually feel? I'm just curious.

Hey Medik,

I just looked at your signature. Where is that mustang with the 351C in it? Did you sell it?