Here's a link to an excellent article in support of Chris's statement about harmonic balancers. It is written by Steve Dinan and posted on the Dinan website complete with illustrations and references. Dinan tunes BMWs, but the information is valid for all cars. I'm sure all will find it helpful:CJSREDPRA said:Does not matter what you do here on the crank pulley, even if you do go to aluminum. The point we're trying to say here is that MOST aftermarket crank pulley's DO NOT have a harmonic balancer on them. Certain RPM's you're motor will start making harmonic vibrations. Not good at all for the motor... Great way to shorten the lifespan of your motor, due to vibrations that are not supposed to be there.
Just make sure that your aftermarket crank pulley has a harmonic balancer.... Otherwise, you will have problems later.
Crank HP-Search would have found that answer for ya :wink:82supra said:ran accros this ebay link. he claims that this 6mge has $200hp, whats up with that? http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=2451449103