<VV> CHT Re: valve seats and "Ping"

[ScottyGrover at aol.com]

I have designed a series of fans for the purpose of improving the air flow  
through a Corvair's engine. the problem with any of the factory stock units 
is  that there is too much space between the fan and the upper shroud 
(turkey  roaster) which allows air to go back by the fan (the technical term  
is"reversion.")  my latest fan design involves a fan with blades which rise  up 
into the airstream and a "fan ring" which fastens to the turkey roaster and 
 which minimises the gap between the fan and fixed-position parts.  This  
allows less air to revert over the fan blades, keeps the air and the   
pressure going through between the fins where it belongs.  
 
Scotty from Hollyweird
 
.
 
 
In a message dated 5/16/2012 10:21:02 A.M. Pacific Daylight Time,  
62vair at gmail.com writes:

John,  there is more to it than a more efficient fan design. The
production fan,  while terrible does provide the required pressurized
air in the box on top  of the cylinders for adequate cooling. I am not
an engineer, so cannot  spout the data to prove or disprove the need for
a more efficient fan,  because all it needs to do is to provide the air
pressure to move the air  through the cylinders and oil cooler. A more
efficient fan may not improve  cooling because there are other
limitations to the system like fin design  on the heads and cylinders,
lower shroud design, and others. The fact that  accessories like the
Otto adjustable pulley which changes the fan speed,  lowers it, tells me
the fan produces plenty of air for cooling, given the  system design.
Mark Durham

Sent from my Windows Phone
From:  jvhroberts at aol.com
Sent: 5/14/2012 18:19
To: FrankCB at aol.com;  patiomatt at aol.com; virtualvairs at corvair.org
Subject: Re: <VV> CHT Re:  valve seats and "Ping"

But did you REALLY need a gauge to tell you  there was a problem? Of
course not.

And Tom had better cooling. A  LOT. The problem with Bonneville is the
power is on for a long haul. Alas,  the engine can't store that much
heat, like it could in a drag strip run,  so, something more was
needed. And yes, as awful as water injection is, it  does provide
improved cooling, well, as long as the tank holds  out.

And yes, a better fan would offer better cooling. Of course,  the
silver lining here is, the stocker is HORRIBLE, so, any well  designed
replacement will beat the stocker hands down. And  obviously,
intercoolers are a proven technology, and that's why all turbo  cars
made today have at least one, and none have water  injection!



John  Roberts