Hi Dick:
I think the theory goes that it creates less total drag pushing the air
around the outside of the car than it does letting it flow through the
radiator and or around the engine and out the bottom of the engine
compartment. If the car was completely sealed, belly pan etc. then your
coffee pot analogy would be applicable.
Jim in Palmdale
----- Original Message -----
From: Dick J <lsr_man@yahoo.com>
To: <ardunbill@webtv.net>; <land-speed@autox.team.net>
Sent: Thursday, December 16, 1999 6:47 AM
Subject: Re: Aerodynamics & Blocked off grills
>
>
> --- ardunbill@webtv.net wrote:
> > Hi Folks. The recent chat about aero made me
> > ponder the '32 Ford
> > roadster body like mine and how it fits into
> > the scheme of airflow
> > things.
>
> I've often wondered about the true value of
> blocking off the grill unless the shape and angle
> of the grill opening are other than oblique to
> the onflowing air. My basis for scientific
> analysis comes from filling the coffee pot every
> morning. Assuming that hydraulics and
> aerodynamics share something in common- when i
> put the coffee pot under the faucet and turn on
> the water, then go back to the counter to put in
> the filter and fill it, the pot always overfills
> before I can get back to it. I've watched the
> water once it gets to the top, and it seems to
> create it's own, nicely shaped cushion with the
> water filling the pot, and then flows neatly over
> the edges. If I hold a saucer over the top of
> the pot to make it like a filled in grill - then
> the water splashes all over the place. I've even
> gone so far with this highly scientific
> experiment as to cut a small piece of cardboard
> that neatly followes the shape of the top of the
> pot, and the water splashes just as badly.
> Doesn't air, once it fills the space behind the
> grill, just form it's own, naturally aerodynamic
> cushion and flow the excess around the filled
> space? I think it would be interesting to take
> something like a '32 coupe -run it with the grill
> covered, and run it with the grill open, and see
> what the difference really is. I'm sure this has
> been done a bazillion times, I just don't know
> what the results are. Dies a 32 Ford or a 55
> Chev with a blocked off grill really run faster
> than the same car with an open grill? I'm sure
> blocking off the grill on a 53 Stude or a 74
> Camaro results in cleaner air flow, but I wonder
> about how much it really helps when working with
> esthetic bricks. Any comments??
>
> =====
> Dick J in East Texas
> - - ECTA #72 - -
> G/FCC - FX/STR
>
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