http://www.dannann.net/eriamjh/77lincoln/Pages/23.html

On your left there is a black canister, looks like a big coffee can. What the fuck is it and what does it do? I have a Lincoln myself and there is also one of them there. Never seen it in any other car.

I know this is retarded, but it's the only way for me to find out.

It's the nos so he can beat ferraris.

No it's not.

It's a vacuum reservour.

Could be a charcoal canister as part of the evaporative emissions system?

My car has one:

http://i355.photobucket.com/albums/r477/TheReverend210/Photo-0015-canister.jpg

Only thing I could think of it being.

Either that, or when he was working on the engine, when he pasused to take the picture, he was holding a coffee can, and decided he needed two hands for his camera, and hence put it down.
Edit: Although if you look closely, there is another one on the other side too, so I dunno.

Vacuum reserve. Like AP2k said.

All right, the fuck does that do? And why don't I see them on cars that are not old Town Cars?

Its so he can clean his car.

All right, the fuck does that do? And why don't I see them on cars that are not old Town Cars?
The purpose of the vacuum reservoir is to provide vacuum when the engine does not produce vacuum.
The older town cars and a lot of older cars in general used a lot of components that use vacuum to operate.Like the climate control system. If you didnt have a reservoir every time the engine was under a load,accelerating or going up a hill the climate control system would default to the defrost setting which would be very annoying.
The doors that cover the head lamps also run on vacuum.

The purpose of the vacuum reservoir is to provide vacuum when the engine does not produce vacuum.
The older town cars and a lot of older cars in general used a lot of components that use vacuum to operate.Like the climate control system. If you didnt have a reservoir every time the engine was under a load,accelerating or going up a hill the climate control system would default to the defrost setting which would be very annoying.
The doors that cover the head lamps also run on vacuum.

Not quite. It cannot "provide" a vacuum when the engine does not, because it doesn't have any valves that hold the vacuum when the manifold vacuum decreases. The purpose of the vacuum reservoir is more to make the manifold effectively largerso you can run more stuff with the same level of vacuum. It is also used on crappy cruise servos that are powered by vacuum which take alot to run both because it lets lots of air into the system and it takes alot of vacuum to pull the servo in.

Not quite. It cannot "provide" a vacuum when the engine does not, because it doesn't have any valves that hold the vacuum when the manifold vacuum decreases. The purpose of the vacuum reservoir is more to make the manifold effectively largerso you can run more stuff with the same level of vacuum. It is also used on crappy cruise servos that are powered by vacuum which take alot to run both because it lets lots of air into the system and it takes alot of vacuum to pull the servo in.
It does provide vacuum, their are one way check valves.

Sorry Argon, but angryonion is correct. There is always a check valve between the reservoir and the intake manifold. On some vehicles, the check valve is integral to the vacuum reservoir inlet. The reservoir provides constant vacuum to the AC servos during low manifold vacuum conditions (such as WOT accel) just as he said.

actually, ur all wrong. its obviously the cars flux capacitor :)

The doors that cover the head lamps also run on vacuum.

Yep, this is the reason the big ass coffee can vacuum reservoir is where it is, and why it's as big as it is. Standard fare for 70s Lincolns.

Yep, this is the reason the big ass coffee can vacuum reservoir is where it is, and why it's as big as it is. Standard fare for 70s Lincolns.

Well, my Lincoln is actually an 88 and does not have those doors on the headlights. But there's still the coffee can vacuum thing.

Heh, when I got my oil changed at Valvoline a few months ago (yeah I know, bitch me out for not doing it myself, but I ran out of time before I was moving and my dad was too lazy to help guide me on my maiden oil change) I overheard the techs there pointing at it and being like "lul teh fuck is that? coffee?" But I'm sure most of you have a low opinion of those people anyway...unless you're one of them. :D

*makes note you can replace the vacuum reservoir with a large soup can*