This is a false statement. Forged pistons do not make more noise during start up than cast pistons. It has more to do with piston to wall clearance and floating pins Vs pressed pins than cast piston Vs forged piston. A looser clearance for more of a race application will have some noise with cast or forged. It seems to happen more in pistons with floating pins than with pressed pin in my experience. I have had stock cast piston AMC engines that made this same noise and nothing at all was wrong with them. Ran one engine for 100,000 miles with no problems. My full floating forged engine makes some noise almost all the time but it was machined loose to rev faster. Another engine we have with forged pistons and tight clearance makes no noise at all. In fact, I had a GMC Yukon with the 350 (since we are bringing the LS1 engine into this) with a cast pistons that had this same noise almost every time I started it cold. It was a wrist pin noise. Went away after a few seconds. A racing style forged piston wants a looser clearance but a standard style like the regular TRW/Speed Pros forged don't require as much. In either case, there is also a range from tight to loose for that particular piston that you can stay within. Stay on the tight side, little to no excessive noise. Go on the loose side, piston noise increases most likely coming from the pin not the skirt. Nick Alfano -------------------------------------------------------------------------- Date: Tue, 05 Oct 2004 22:17:38 -0400 From: biljoh@xxxxxxxxxxxx Subject: Re: Forged Piston Noise when cold, Piston material or pin placement? To: mail@xxxxxxxxxxxx Message-ID: <ADVANCES62A1XvpFVjC0000003e@xxxxxxxxxxxxxxxxxxxxxxx> Forged pistons will make more noise on a cold motor than cast pistons until the engine warms up. I would imagine that as the engine wears over time the cold noise could get louder/worse as the cylinder wears increasing the clearances even more. "over .003" could now be over .005. Piston side skirt wear and cylinder lning wear combine. This is a common problem on modern engines using forged pistons most notably LS1 motors that have had lots of comlaints about piston slap on start-up. The pin placement may or may not make the situation worse I have never researched that but someone here will be able to adress that.