1976 air cleaner

[sjckn]

What is the canister attached to the air cleaner assembly for? Some kind of emissions thing? Looks useless.

[Dan Szwarc]

It's a resonant chamber. It acts as a muffler. It is not useless.

It's quite stylish, also.

[jon schapiro]

I thought it also contained activated charcoal to absorb any gasoline fumes in the air cleaner

[Dan Szwarc]

That I do not know. I don't think it would work properly if it had material in it.

Here's a thread from 2008:
Subject: What is this thing on the air cleaner?

My guess it's that it's some kind of resonator to tune out intake
resonance, but that's just a guess.

That is correct! It is called a Helmholtz Resonator.

Some newer cars have a Helmholtz Resonator in their air intake tubes. A plastic blob molded in usually at a right-angle to the direction of airflow to the throttle body. The plastic ones I have seen are smaller volume, so they must be tuned to a higher resonant frequency. The Ford 460 H/R's that used the oil filter cases must have been tuning to a low-frequency resonance.

Subject: What is this thing on the air cleaner?

Not necessarily so! The helmholtz resonator is just more effective with a higher volume. The cross section of the opening an the lenght of the tube that connects the resonator volume to the rest of the assembly has also its effect on the actual resonance frequency.

For more details: http://en.wikipedia.org/wiki/Helmholtz_resonance

I guess the resonator is there to dampen the hissing sound of the carburetor near idle.

[sjckn]

I'm not sure if mine has some sort of fabric type packing in it or if some varmit got in there and tried to build a nest.

[thegermanfan]

packing inside of the can would diminish the effect of the Helmholtz resonator. Someone not really understanding the function has tampered with it. Maybe rodents. They aren't very bright...

[action]

Goin off topic ...


Then there is the smart rat!
AKA Rat Fink

Action

[Dan Szwarc]

Rodents definitely do not know how a Helmholtz resonator is supposed to work. Stupid rodents.

[papawayne]

Skidding off the highway completely, rodents do thoroughly love headliner material. Wayne

[frasern]

Off the hiway, in the ditch, I think it is the insulation they love. On older Ford trucks, the cardboard survives better on the cheap ones with no headliner insulation, as mice are not drawn in there.

[rick]

Ha - I used to put those Big Daddy Roth decals on my car models when I was eleven. Man, that was a long time ago.

[TonyC]

I still love those whack-looking Roth pictures. There's just something creepy-yet-funny about them all.

Something else rodents seem to like: Build sheets.

---Tony