This is probably ridiculous question but I can't seem to find a chart on google that explains typical parts of a classic american car. I always seen that round disc like cylinder on top of many muscle car engine . what is that called? PS - I am no mechanic just curious. thanks
You're talking about a classic air filter housing.
Older style air filters were round in shape and sat inside a round metal enclosure.
This is a Holden straight 6 from the 80s, where the air filter element is housed and sits on top of the carbeuretor.
It's interesting to note that even modern cars, the check engine light still has a silhouette of an classic shape engine with the air filter sitting on top.
As stated it's a circular air filter. It's positioned there because it sits on top of the carburetor. Modern cars rarely use circular air filters, they are usually square or rectangular and are connected to the air intake system by tubes.
It isn't just musclecars which used this configuration, it was extremely common on carbureted engines.
For the sake of completeness: let me add that even some VW models of the 70-80 and 90s were equipped with circular filters, the Motronic (no carburator but pre mixing of fuel and air) occasionally used them. But on the contrary I own an 1991 semi electronic carburator powered VW Rabbid (Golf) MK 2 which has a square air filter. Motronic: Seat IBIZA with VW 1.3L (1993)
I can only post 2 regular links, so here is the third: Carburetor: MH Engine of Rabbid MK1/MK2 (1987), 1,3L/54HP (http://) i.stack.imgur.com/omEmu.jpg
It's relative to whether the engine uses a carburetor or has fuel injection. The round air filer housing sat on top of a carburetor where the gas and air are mixed before going to the cylinders. Newer cars use fuel injection and the plumbing for the air flow is different. The air usually goes through an airbox where a flat, square filer is in place. The fuel is then injected into the air flow (throttle body) or directly into the cylinders (a better design).