What it this? Located on passenger side firewall. 1964 330

[McPorGuy]

What is this opening on the passenger side firewall? What is the function?

Firewall is flat on the inside of the car with no openings. The "bulge" in the engine compartment firewall is covered by this newer looking rubber flap.

Thanks for your help.

 

[Dutchrebuild]

Cowl drain

 

[snakeoil24]

air conditioning freon ports??

 

[lewtot184]

Water drain

 

[icetech]

Detroit musclecar makes new flaps for that if you ever need one

 

[493 Mike]

A piss poor design too! I filled the inner lip with fiberglass resin to raise the floor of the drain. There is another one of these on the right side behind the fender.
Mike

 

[Dave6T4]

They usually get plugged up with small leaves, pine needles, etc. and no longer drain. Then, the cowl starts to rot out.

 

[ckessel]

One of the many holes that got capped off on my 65.

 

[493 Mike]

I have posted on this area previously but, many may not have read my tale of woe. I had to remove the entire cowl piece to repair rust damage, and before reinstallation I lined the entire cowl bottom with fiberglass and resin for a waterproof repair. I used gloss black Rust O Leum enamel to topcoat the fiberglass. I was able to stuff cardboard thru the interior fresh air opening for paint masking to keep it dark inside.
Mike