Using a smaller crank Pulley
 

Thanks to Kevin930T I purchased an Electromotive XDI ignition set off of the used parts section of the forums.

The only problem is that the setup came off a 2.0L and therefore has a smaller crank pulley. Is there any problem with running the smaller pulley on a later car?

Rich, I don't know the answer right off, but I know that you don't want to speed the engine fan up to the point that it cavitates and stops moving air efficiently (aka - the fan pulley and crank pulley ratio have to be in sync) - so definitely worth looking into and I know that there is a lot more info on this in the 911 forum (from people like J. Walker, Bruce/flatsixpack, etc.).

Thanks Ronnie. I certainly assumed that the fan speed would increase, but wouldn't have assumed that it could be detrimental. I'll take a look on the 911 forum.

It will increase in proportion to the changed diameter - eg 10% smaller = 10% faster fan. The only solution if you wanted to keep same fan speed would be to reduce fan pulley same amount - if possible.
Alan

maybe I am wrong, but wouldn't a smaller dia crank pulley actually slow the fan speed down?

~chris

Y'all are backwards.

He's stating the crank pulley is smaller. This would slow down the fan.