<VV> Engine Bay Air temperature experiment
RoboMan91324 at aol.com
RoboMan91324 at aol.com
Fri May 22 22:02:04 EDT 2015
Thanks for performing the experiment and for sharing. I have a few
questions and comments. Please don't think of this as "looking a gift horse in
Is it possible for you to perform the same experiment once the seal is
installed? Hot air and exhaust exits the engine from beneath and the fan will
suck that hot air/exhaust into the engine compartment along with outside
air from above.
It doesn't appear so but I don't want to "read between the lines" of your
description. Did you by any chance read temperatures or have someone read
temperatures, remotely while driving? If not, can you do so with your
equipment? If you had to stop, get out and access your engine compartment to
read the temperatures, you may have irrelevant data. If you stop for a
while with the engine off, heat from a hot engine will rise up into the engine
compartment and heat the air significantly. Starting the engine will suck
the hot air through the fan and out the bottom but I am not sure how
quickly that will happen. Just opening the engine compartment lid will change
Real temperatures taken while driving under a number of scenarios would be
best. The engine generates more heat while loaded and at higher RPMs but
the fan also sucks more air (CFM) into and through the engine compartment
at higher RPMs as well. Even with a hotter engine, I suspect the air in the
engine compartment will be relatively cool while driving at speed.
Your unshielded turbo and exhaust tubes in the engine compartment will
skew your data too.
In a message dated 5/22/2015 4:20:22 P.M. Pacific Daylight Time,
virtualvairs-request at corvair.org writes:
Date: Fri, 22 May 2015 16:20:08 -0700
From: kevin nash <wrokit at hotmail.com>
To: "virtualvairs at corvair.org" <virtualvairs at corvair.org>
Subject: <VV> Engine Bay Air temperature experiment
Message-ID: <BAY177-W46596E336F548C48BE4215D3C00 at phx.gbl>
Content-Type: text/plain; charset="iso-8859-1"
I've been fine tuning my EFI set-up recently and was curious as to how hot
the engine compartment air was getting while the engine was running during
normal cruising. The engine compartment air temperature was a particular
concern to me as I don't have a heat shield on the turbo (yet) and, until
very recently hadn't bothered to put on the rear engine compartment seal
either. Anyways, I thought I remembered someone on this board had asked about
engine compartment air temps sometime ago and I just got done doing the
test, I thought I would share my results. Since I was concerned about the air
temp just before it enters the air cleaner, I put a digital thermometer
probe on top of the throttle body's, not touching any metal, approximately 1"
away from the air cleaner.
Morning before starting engine and driving to work: T= 53F, 10 miles
later, T=67F, head temperature was well below 300. Afternoon before starting
engine and driving home: T=83F. stopped at gas station to get gas after 2 or 3
minutes of running- right after re-starting the car, T=97F. Continue on
home, head temperature gets to 300 degrees, and the digital thermometer
reads.... 82F. I've done this same test 2 days in a row now, and have gotten
the same results each day, and I also verified that the digital thermometer
agrees well (within 1 degree) at 52F and 70F with our outdoor thermometer.
For curiosity's sake only!!
63 Turbo, EFI daily driver
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