Scott, interesting question and I think the answer is that the seal should
be in place. A couple of thoughts on this. I once bought a basket case 1970
Corvette with modified 454 and body changes that included a bump on the hood
with the intake facing and just in front of the screen so I could actually
see the air filter when driving. With all the modifications a lot of heat
was being generated and I was concerned that all that hot air was being
pulled out of the hood and passing over the carb. So I stuck pieces of white
wool all around and in this duct as is done wind tunnels. Once the car was
moving,lo and behold, all the tags were indicating air flow going foreward
to the carbs and the obvious explanation was that the pressure build up at
the bottom of the screen was greater than the air passin over the engine. I
even drove at 60mph and shifted into neutral(it was a 4 speed) and letting
the engine idle to minimize the effect carb induction and those wool tufts
insisted on trying to get back into the engine compartment.
The other point is that most cars have their ventilation inlets infront of
the screen to take advantage of this area of pressure, that is why you can
drive on "vent" and get a good flow of air without switching the fan on.
Even more noticable is if you put a bug deflector on the front of the hood
the pressure is lost and ventilation is only achieved by switching the fan
on. This has happened on both my Subaru Outback and my Toyota 4 Runner which
have very different profiles.
My Brick is not a runner bit since I am installing a relatively mildly
modified engine with Mustang shorty headers I will be making what I
understand is a hot engine compartment even hotter(I have never driven the
car). One solution I am considering is to have outlet grills behind each
front wheel ducted from the engine compartment. In each duct there would a
thermostatically controlled extractor fan set to come on well before the
electric fan that will be installed on on the radiator. Thats a theory
anyway, it will be some time before I get to this point.
Hope this helps.
Owen Evans
VIN #1355
///
/// bricklin@autox.team.net mailing list
///
|