TravMsns

I'm thinking of eliminating the vacuum canister under the washer fluid reservoir. From what I can tell it won't really do anything for my setup. I'm not running a PCV valve (2 breathers), no emissions junk, No A/C. According to my figures, the only vacuum I need is for the headlights (this is manifold vacuum), the power brake booster vacuum (comes from the carb), vacuum advance (comes from the carb), and vacuum for the tranny (manifold vacuum). I can hook all these directly into their corresponding ports. Do I need to hook up the vacuum canister? What pupose does it serve? Will everything work ok if I eliminate it?

Smokehouse69

Mine on my 69 was bypassed when I got it due to leaks, I tried to patch the leaks with JB Weld, but I couldn't reach all of them with the tank in the car. I'd like to remove it and weld up the leaks but it is a b!tch to get out. Anyway, all my vacuum devices worked well with my idle vacuum at about 15 inH2O, without the vacuum tank.

TravMsns

TTT, anyone else's opinions?

lbell101

I believe it's only there as vac storage for:
1. When the engine is off.
2. When the engine is producing low vacuum (up hills ect)

Tex71BB

Are you talking about the vacuum reservoir or the vapor canister?

thejaf

I think he's talking about the carbon canister, from his description. i replaced the carbon canister with a vacuum canister to help out my power brakes due to overly choppy camshaft. The carbon canister was easy as pie to get out, just make sure that the lines going to the gas tank are securly plugged and get a vented gas cap.

Rockn-Roll

The canister you are talking about (under the washer fluid) is the fuel vapor recovery system. While the engine sits the fuel bowl of the carb evaporates. The system is designed to store the fuel vapor in the canister so when you start the car it will suck the vapor into the engine and burn it instead of letting it vent to the atmosphere. It is also designed to vent the fuel tank though the intake manifold. Removing it will make your garage stink and could cause pressure (or vacuum) to build in the fuel tank.

For hot rodding I do the same thing you do with some of the vacuum connections mainly to eliminate devices that could fail, and are only intended to function during the initial warm up of the engine, i.e. the temperature switches that control where vacuum is to be delivered at certain temperatures. One ported line from the carb going straight to the vacuum diaphram on the distributor, and one line from the intake manifold going to the power booster, EGR block off plate, but I still have a PCV connected to the manifold to prevent exhaust/intake gases from building in the block and exploding...I suppose connecting both fittings to the air cleaner would be fine for a clean burning engine, but when you start to get blow by from worn rings then you may be getting a lot of smoke in the block that won't clean out as fast as with a connection to the intake manifold. But, I also WANT a fuel evaporation cannister so my garage doesn't stink!

Jvette73

Im with Rockn-Roll on this one. As long as you dont mind the fumes there are really no other drawbacks to removing the evap canister.

thejaf

Yes, I only removed mine to give me a place to put the vacuum reservior for my brakes. That reservior was the same size as the carbon canister.