<VV> Fan Belt Tension

[kevin nash]

> 
> Message: 1
> Date: Wed, 11 Apr 2012 16:11:14 -0700
> From: Mark Durham <62vair at gmail.com>
> Subject: Re: <VV> Fan belt tension
> To: Michael Kovacs <kovacsmj at sbcglobal.net>
> Cc: VV <virtualvairs at corvair.org>
> Message-ID: <-5941913159328312455 at unknownmsgid>
> Content-Type: text/plain; charset=ISO-8859-1
> 
> hum or vibration can be seen reving engine and watching it, n.o
> vibration/hum with belt removed or tightened tight. Mark Durham
> 
Mark- It might be that your fan pulley or your idler pulley are somehow not spinning true enough to stay quiet, or perhaps your belt has a high or lowspot in it that would cause the hum or vibration that you describe. Here are some things you might want to check: Take the fan belt off, and spin the fan by hand and watch the pulley groove- it better not wobble up and down (towards the fan and up away from the fan) or your fan pulley has a bend in it and is likely the cause of the hum. I dont know what the "acceptable" amount of wobble is, but the stock pulleys are not the most accurate pulleys in the world- but they are also not known to be so wobbly as to cause the noise you are hearing- unless they have been damaged in some way.Also, check the condition of the belt, making sure that there are no obvious high or low spots- if there are- figure out WHY, as new fan belts dont have those, and if they do, its because the pulleys have some sort of problem that is causing the unusual belt wear.Kevin Nash