<div dir="ltr">I haven't done flow calculations in a long, long time, and Fluids was not among my favorite subjects back in school... so with that said, my gut feeling is that Mark's 56% blockage is probably somewhere in the right ballpark but dependent on factors like whether the airflow is laminar or turbulent, maybe Reynold's numbers.... now I'm just spewing stuff I learned 40 years ago. Mostly to say, there might not *be* a good way to calculate this outside of a lab with a flow bench; really, the thing to do is try it, and take measurements. No idea if you can see high-side pressure while on the road but I doubt it. Any readouts for coolant or trans temperatures? <div><br></div><div>SO</div><div><br></div></div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Fri, Jun 18, 2021 at 1:03 AM magreer67 <<a href="mailto:magreer67@gmail.com">magreer67@gmail.com</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><div dir="auto"><div dir="auto">Wouldn't that be 56% blockage and 44% open to flow through?</div><div dir="auto">Mark Greer</div><div dir="auto"><br></div><div dir="auto"><br></div><div dir="auto"><br></div><div id="gmail-m_-202123088828031218composer_signature" dir="auto"><div style="font-size:85%;color:rgb(87,87,87)" dir="auto">Sent from my Verizon, Samsung Galaxy smartphone</div></div><div dir="auto"><br></div><div><br></div><div align="left" dir="auto" style="font-size:100%;color:rgb(0,0,0)"><div>-------- Original message --------</div><div>From: Cecil Bearden <<a href="mailto:crbearden@copper.net" target="_blank">crbearden@copper.net</a>> </div><div>Date: 6/17/21 11:34 PM (GMT-05:00) </div><div>To: <a href="mailto:at@lists.antique-tractor.com" target="_blank">at@lists.antique-tractor.com</a> </div><div>Subject: Re: [AT] Airflow calculations of perforated metal for radiator screens </div><div><br></div></div>
<p>The .188 diameter staggered pattern gives .444 sqin hole area
over a 1 sq in area. So I guess it would result in a 44%
blockage. However it would be tabout 5 inches from the grille and
then the A/C condensor sets about 6 inches back from that. I
think there would be sufficient room to pull air from above and
below. It just may cause some additional drag at high speeds. I
think I will try it and make it easy to remove in case it blocks
too much airflow. I have to do something. Time and ability to
work on this stuff gets more valuable daily...<br>
Cecil<br>
</p>
<div>On 6/17/2021 7:48 PM, Brad Loomis
wrote:<br>
</div>
<blockquote type="cite">
<div dir="ltr">The 455 diesel lawn tractor I use at work has a
pull out screen ahead of the radiator. I'm not there so I can't
measure it. But I will try tomorrow and report back. It does
keep the foxtails, thistle, mustard, and whatever else I kick up
out of the radiator.
<div>Brad</div>
</div>
<br>
<div class="gmail_quote">
<div class="gmail_attr" dir="ltr">On Thu, Jun 17, 2021 at 5:23
PM Cecil Bearden <<a href="mailto:crbearden@copper.net" target="_blank">crbearden@copper.net</a>> wrote:<br>
</div>
<blockquote style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex" class="gmail_quote">I
had to wash the A/C condensor and radiator out on my 2011
Chevy truck <br>
yesterday before I could make a trip to pick up some auction
items. I <br>
put the gauges on my a/c system and it showed 35 low and 350
high. <br>
before I did anything I went to the water hose and got it down
to 150 <br>
pretty quickly on the high side. The amount of bugs was
crazy. I will <br>
have to remove the radiator and condensor to get them clean as
there is <br>
no room to get anything in the front or behind the fan. I
have one of <br>
those heavy cowcatcher style grill guards in the front. This
truck has <br>
about 170K miles and has made 3 trips to Alaska, so it may
have more <br>
bugs than usual, but the bugs and thi8stle seeds are terrible
here and <br>
getting worse. I want to put a piece of perforated metal
behind the <br>
grill guard to catch the bugs. If it cuts the air down, it can
still <br>
come in between the screening and the grill. I don't think it
will make <br>
a lot of difference in the amount of air entering the
radiator, but <br>
maybe catch the bugs and fluffy crap in the air... When we
figure <br>
airflow into a home, we cut the flow through a window in half
when a <br>
screen is used. I am looking at a peforated metal with
holes .188in <br>
in diameter and offset centers so it gets the most holes per
square <br>
inch. Does anyone have any experience with this type of
screening or <br>
have a formula to determine if it will cut the airflow too
much. I think <br>
the area behind the grill guard and the grill is wide enough
to keep <br>
from cutting down the air flow. Traveling down the road at
60mph it may <br>
deflect some air around the grill instead of through..<br>
<br>
I just don't want to have to remove this radiator again. I
have to use <br>
a stepladder to work on the d&%$^d thing it is so tall.
It is stock for <br>
that year, but the manufacturers want to see how far the
drivers can <br>
jump to get into a pickup nowdays. I remember a 63 and 66
chevy 1/2 ton <br>
pickup we worked out of on the farm every day. Hauled 20 head
of cows <br>
in a bumper trailer with no brakes into OKC Stockyards.
Loaded 60 <br>
bushels of wheat to haul to the elevator when the lines were
long and <br>
the grain truck had not returned. Now, I have a 3/4 ton that
I have to <br>
jump into or pull myself in with the steering wheel and 30
bushels of <br>
rye in the bed causes it to squat, with twice as much tire
under it than <br>
the old ones had.. It doesn't ride all that much better,
just cooler <br>
when the A/C works. OK rant off.....<br>
<br>
Cecil<br>
<br>
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