<VV> My new experimental fan

[kevin nash]

Message: 3
Date: Sun, 12 Nov 2017 17:39:53 -0600
From: Mike Kost <kmkost at sbcglobal.net>
To: "virtualvairs at corvair.org" <virtualvairs at corvair.org>
Subject: Re: <VV> My new experimental fan
Message-ID: <7dd1dba8-c59d-df3d-a485-c2aef52154cb at sbcglobal.net>
Content-Type: text/plain; charset=windows-1252; format=flowed

Would a solid ring mounted on legs bolted to the engine cover bolts that
would have a minimal clearance to the fan with a soft gasket to the
shroud sealing the inlet from the outlet help with efficiency?

Mike Kost

Mike- that's a neat, clever way to tighten the fan to shroud clearance! To answer your question though,
no, there is no efficiency gain from tightening the gap... the output of the fan is increased but both the drive
horsepower and the air horsepower (theoretical minimum hp usage based on cfms and pressure) are increased by the same amount, thus no efficiency gain. The reverse is also true- increase the gap and the output goes down and both the air horsepower and drive horsepower go down. Tweaking the fan gap
is a good way to fine tune the output of the fan, but it is just a simple horsepower usage vs cooling trade.
Kevin Nash