my pops put a chrome fan pulley (jegs or summit) on his bb 427. it wobbles and tosses the fan belt at about 6500 rpm. anyone know the max amount of, ummm.... well, i'm guessing it would be called "vertical runout" (front to back) for a fan pulley?

thanks in advance.

 

Just off the top of my head, I probably wouldn't want more than .015" or so.

Is it bolted on correctly? Is the water pump shaft bent? Was the mounting pad on the pump shaft clear of debris? Is it in proper alignment with the crank and alternator pullies?

 

thanks for the reply. the water pump is new... well, it's a chrome reman'd unit from jegs/summit and went on at the same time as the pulley. i will have to double check the alignments as that i gave them just a quick glance, but the pulley visibly wobbles when turned by hand. i'll get a dial gauge out and check it, but i'm guestimating more than .03".

 

A lot of the cheap chrome **** from Jegs is just that...cheap. If you can see it wobbling turning it by hand, and its bolted on correctly, take it off, call jegs, and exchange it.

 

Take it off and turn it half a turn and try it. If it still wobbles, try the old pulley. If it wobbles send the pump back. If it runs smooth send the new pulley back.

 

Ide Try The Old Pulley On The New Pump As Well And Like The Other Guy Said About Cheap Chrome From Summit And Jegs I Agree When They Dip The Pulleys In A Hot Dip Then It Can Warp Them Causing Your Wobble At 6500