Oil bath air cleaner hookups

The charcoal canister collected fuel vapors given off by the tank (hot summer day). Stored there till the engine starts, then pushed by the fan into the air cleaner and burned. So, you can plug them.

In Fig. 6-2, do you actually have that spring and thermostat? The stat expands from ambient air temp. I don't know of any small hose connection for emission. '71 and later cars (maybe Ghia) used a vacuum diaphragm instead of the thermostat. Could that be what you have?

The big round opening underneath is for a hose which gets hot air off #2 cylinder fins. If you live where temps get down to ~45F you must have it. The heated air (controlled by stat) prevents nasty carb icing.

The oval "snout" provides most of the engine air.

Speedy Jim

Not according to Fig. 7-1 (Bentley bus book, "Fuel Section") -- air comes into the canister from the fan housing. My housing has a little

1/2'' outlet on its right upper shoulder which I presently have blocked off.

I find this connection puzzling. Why pump air into the canister from the fan housing?

It is the second 1/2'' inlet that comes from the fuel tank, per Fig. 3-1 of the same book, same section. The canister is not part of this circuit.

I reckon you are right.

Yes -- exactly like the photo. In fact, that could be my air cleaner.

No -- a thermostat and a flap-type valve. Just like the photo. Note that the photo of the air cleaner with the spring/thermostat is labeled "The

1971 air cleaner." So this is the correct air cleaner for my 71 bus.

Doesn't -- or rarely -- gets that cold here. But for the sake of completion . . . how or where does the hose connect to the hot air off #2 cylinder fins? I do have a spare hole in my rear cover plate (item #12, Fig. 6-4, "Engine and Clutch," same book) near the right hand heat exchanger feeder tube hole, down near the pulley. I have been wondering what that hole was for, so does this preheated air route through there? Where does the lower end of that hose connect?

Right-o.

The charcoal absorbs the vapors. When the engine starts, the fan blows air over the charcoal and releases the vapors into the air stream for burning in the carb/eng.

Ah! I see it now. The one from the fuel tank should be connected.

But not that one.

Yes, the hose goes thru the hole in the tin. Underneath there used to be a sheet metal assy "stove" or hot air pickup. Same part used on cars from something like '70 thru '74 so you may be able to find one.

Section 19.

Bottom of pic, Item #1 is the pickup.

Jim

What vapors? The inlet to the charcoal canister is connected to the top of the fan housing. There are vapors in the dog house? Dog farts? This continues to puzzle.

I imagine it should be, to accomplish the evaporative emissions control. However, there is no sign of this hose anywhere on the bus. Is is possible to see the place on the fuel tank where the hose is supposed to connect to without dropping the tank or something?

I reckon I should plug it until the hose connection from the fuel tank is re-established.

Whoa -- a totally new part, to me! Bustedbus.com might have such a thing.

[snip] -- read the earlier posts before chiming in

Wait -- I see it.

Section 25-20 clearly shows that the canister has /two/ inlets -- one from the fan housing, one from (I presume) the fuel tank. Bentleys does not show it (no surprise, the book has other errors).

But wait -- that leaves us with a spare, unaccounted-for inlet on the air cleaner.

1/2'' Inlet 1: From the activated charcoal canister. Fan housing and fuel tank evap line plug into that. 1/2'' Inlet 2: uh . . .

from the crankcase breather....(little port on the oil filler)

------------------- Chris Perdue

"Sometimes you're the windshield, sometimes you're the bug!"

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DOH !@! Jim

No, no, Jim, allow me:

Double DOH!

Fig. 7-1 shows it. One hose from fan. Other hose *to* the air cleaner.

But that canister must have a 3rd port. It is a connection for a small hose and that hose comes *from* the fuel tank (or from the vapor loop on a Bus). That allows vapors to enter the canister; they will later be pushed into the carb by the fan.

Speedy Jim

Slowly the light is dawning. Fig. 3-1, Section "Fuel System", Bentley's bus book has an illustration of a later-than-1971 bus evap arrangement. On that bus, I see that the fuel tank has two two vent lines, one on port side, one on starboard side. They apparently sweep rearward, then up the "D" pillars, through some cylindrical thingies, then down again and join at the centerline of the bus, at the aft-top of the engine compartment. A single hose from the junction of the two lines goes into the air cleaner, without going through a charcoal filter.

They don't provide a similar diagram for the 71 bus with canister.

, section 25-20 shows the connections to the canister.I don't think there is a 1971 bus fuel tank setup shown anywhere on that site. Where would I look on the Wonderbus to see if I can find the fuel tank's old evap line? Does it connect to the tank in a location that is accessible w/o dropping the tank?