I have a stock 99 GSR block. I was wondering if the internals have to be balanced if I change the crank pulley to a lightweight one.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by SPOONfed-Rex &raquo;</TD></TR><TR><TD CLASS="quote">I have a stock 99 GSR block. I was wondering if the internals have to be balanced if I change the crank pulley to a lightweight one. </TD></TR></TABLE>
No, when you get the 'rotating assembly' balanced by a shop that's just referring to crank, rods+pistons.

I lighter crank pulley would be roughly the same as throwing a lighter flywheel on as far as affecting engine balance.

In other words, don't worry about it

 

Wow... Finally a decent answer...Sweet thanks for the info

 

If you are getting rid of the stock pulley with the injected rubber in it for a solid metal pulley with no damper such as the ctr you may want to do some more research. The rubber is in the stock pulley to absorb some of the vibrations coming off of the crank that could possibly wear out bearings faster. It seems some people have no problems running pulleys like the ctr but most people with high horsepower motors use a damper such as an ATI or Fluidamper which do what the stock pulley does except better. Personally I would just stick with the stock pulley.