NACA duct plug ?

[John Johns]

I'm running cone filters and have removed the airbox. Has anyone come up with a solution to plug the NACA duct when running into the occasional heavy rainstorm? I've been considering something that might velcro in on the inside. I suppose duct tape would work in a pinch.

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[RoyV101621]

I had never thought of using a duck to plug the hood. Have you considered marketing your idea?

 

[John Johns]

Thanks Roy. I was going to use a chicken, but felt the duck had superior aerodynamics.

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<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by RoyV101621:
I had never thought of using a duck to plug the hood. Have you considered marketing your idea?

<HR></BLOCKQUOTE>

 

[JimDavis MT 97GTS 650R]

Hi John. I too had concerns when I modified my air intake. I tried many different ways to plug the NACA duct to keep the rain out, but concluded that should the plugging material be ingested, the results would be as bad as the water. Of course, with cones you wouldn't have this problem, but short of fashioning a molded rubber plug with a seal that could be inserted in the hole from the outside and easily removed when not needed, it's a lot of work for very little benefit. Such a "nose plug" would be a great entrepreneurial gimmick, if one wants to assume the liability. They could even put a snake logo on it, and a chain like the one in the kitchen sink! With my HMS carbon fiber unit, I have had no problem. Of course, common sense dictates your decision to drive in a downpour. With the cones out of the direct path of the air intake, I doubt you should have much problem. I'd worry more about the tires hydroplaneing, than the intake sucking in water.

 

[Marv S]

69 Mach 1 Mustang with Shaker Hood Scoop
70 GTX with Air Grabber hood

Did these cars, or others from that vintage with similar cold air induction have problems with heavy rain? Seems they got "ram air" forced into them that went directly to the air cleaner element.

 

[JimDavis MT 97GTS 650R]

Marv, Although the ducts are a "ram air" type, the stock air colection box has a rain baffle to divert rain water from the intake. Some feel that by eliminating this baffle feature, a better ram flow is achieved. The problem is that if large quantitys of water enter the intake instead of being deverted, severe engine dammage may result. Small amounts of water have little effect, and in some applications have even been beneficial.Atomized water in reasonable amounts through the intake creates a cooler, denser intake charge producing more power with less detonation. A heavy shot of water though, may cause fowling of the combustion or even worse, hydraulic lock which bends and brakes stuff! The issue here centers around (modified) air intake applications. The stock units dont have much problem.

 

[Marv S]

NACA= National Advisory Committee for Aeronautics

 

[Matt M PA]

To answer the question about the older musclecars. I know for a fact that the '69 1/2 Bees and Runners, as well as Shaker hood E-Bodies, had bases that were kind of like trays. These had hoses at the corners that directed the water around corners of the engine, so that it would drain away from the carbs. They used heater hose pieces about 6" long.