1970 Grand National Cowl Induction

[nitrometal]

I've started hacking away at the firewall to install the cowl induction air cleaner system for my period correct racing 'bird.  I've seen lots of photos of the engine bay with the air cleaner assembly in place but never with it removed.

I have a plan on how I want to do it but I would love to see how they did it back in the day (hell, I'd like to see how they do it now).  They probably didn't worry about rain and other weather getting inside the cockpit and just patched some kind of tunnel system to feed the air into the air cleaner.
However, I am concerned about the rain coming in, or even when I wash the car, so I'll need some way to keep it weather tight.

Does anyone out there have some detailed photos, drawings or maybe explain how it's done?  Maybe, I'm way off base on my plans and need a second look on how to approach this.

[Aero426]

The firewall of a GN car is completely fabricated from sheet metal.   They built a simple rectangular air plenum box into the firewall below the cowl opening.   If you remove the fiberglass air cleaner from the sample photo, you will see the rectangular opening.  

If you scroll down the photos of this article, you will see an example of how it was done.
http://www.superbirdclub.com/InsideNichels.html

[nitrometal]

Thanks Aero426!     I haven't seen that one before.  I just enlarged it as much as I could and it looks like there is some sort of baffle in there.  Maybe that's what keeps water from being sucked in there.    Man, I wish that I could see one in person.

[Aero426]

I'm not sure what kind of an element, if any is in the air cleaner itself.   Pretty sure water infiltration was not much of a concern on those cowls.   

[Ghoste]

Those races were typically called if it rained. 

[nascarxx29]

Here a shot of the one on Buddy bakers daytona few pictures down
http://www.gogearhead.com/69Daytonaracecar/index.html

[nitrometal]

Those races were typically called if it rained. 

Yeah, I figured they weren't concerned about the weather.

Here a shot of the one on Buddy bakers daytona few pictures down
http://www.gogearhead.com/69Daytonaracecar/index.html

Thanks for the link.  There's a few in there that I haven't seen before but none with the air cleaner removed.

[Seabeckredneck]

Hi Nitro,
  While I'm 10 years behind you, I just came across this thread. I am building a (street legal) Superbird race replica. I would be interested in seeing what you came up with and pick your brain for ideas and suggestions.
  I'm located in Washington state but I grew up in Griffith, Indiana. I just wish I knew about Ray Nichels' shop back then!
  Thank you for your time.

   Chris

[Ghoste]

How big is Griffith?

[Seabeckredneck]

  Well, I moved away in 1980 when I joined the Navy, but back then it was about 15,000 people, so not a big town, You didn't have to drive more than a few minutes and you were in the cornfields!
 

[odcics2]

Hi Nitro,
  While I'm 10 years behind you, I just came across this thread. I am building a (street legal) Superbird race replica. I would be interested in seeing what you came up with and pick your brain for ideas and suggestions.
  I'm located in Washington state but I grew up in Griffith, Indiana. I just wish I knew about Ray Nichels' shop back then!
  Thank you for your time.

   Chris

Email him. He hasn't been on this forum since 2014.