Activated Charcoal filter ?

[GotaT]

I have a 71 and my car no longer has the Activated Charcoal Filter. I am noticing that when I fill the car up w/ fuel I am seeing a small drip coming from the Drv side Fender area - the Tank . there is an upper hose that should be connected to the tank that is no longer there. I believe this went into the Charcoal filter, and so when I fill up the "extra" fuel is dripping from where this hose would have been connected.

Do I need to have the Filter ? If not, can I just plug the tube off of the Tank?

My car has Webers

[tcar]

I thought the filter first appeared in 73? Not sure, tho.

[3.2 CAB]

I know some 911's had a charcoal canister or what Porsche calls a "carbon canister" mounted up under the left front fender. I can't remember the years they were this way. Some had them in the rear.

[RWebb]

you want to keep that filter - also, you may have a cracked tank - look up inside the LF fender.

bunch of posts on this - use emission as a search term

also you prob. should replace the vapor hoses - do NOT use regular PVC hose; use hose rated for gas fumes to avoid a serious fire hazard

more dangerous if you have a garage; but most in La. have carports... still not real safe

post again if you need help after reviewing the threads.

[javadog]

Okay,

There are charcoal cannisters (activated carbon cannister, or whatever you choose to call it) and vent and expansion tanks. They are not one and the same thing and they have both different functions and a need to be located in different positions with respect to the fuel tank. On a '71, the charcoal cannister was located in the lower left of the front of the trunk, adjacent to the left battery. What usually resides up high in the left front fender of a 911 is an expansion tank or vent tank.

Your fuel tank needs to vent to the atmosphere; air has to be able to enter the tank to replace the fuel that you burn when driving. Also, there needs to be a provision for the slight expansion of the fuel in the tank, as it gets hot. After 1968, the feds started to dictate that cars needed to quit polluting so much. Rather than vent the fuel tanks directly to the atmosphere, they were vented to these charcoal cannisters which collected evaporated fuel when the car was not driven. Air was pumped from the engine fan during operation to force the vapors to the engine where they could be burned.

My suggestion is to plumb the car the way Porsche did originally, since there really isn't a downside to it. Your garage will smell better if you do. Here's a link to an earlier thread that has some diagrams that you'll find useful:

tank ventilation-MFI diagrams

JR

[GotaT]

After styding my car I seem to be missing the Line coming from the Tank under the fender To the Canister and the Two from the canister to the Back of the car...
If these 2 were connected to the Canister where would they end up on my Car in the Engine area since I am running K/N's ? Where do the 2 Hoses hook up to???

What can I do to get it my system to work ?

[jbrinkley]

thanks for pointing out we all have carports Randy, lol

[RWebb]

me from Baton Rouge....

[GotaT]

Anyone know a way I can connect it back? I was thinking of looping the canister .. ??

[Fast Corners]

Well the one line to the cannister is a fabric braided rubber line (10mm I think). It connects on the fan shroud and travels down to the center tunnel where it connects to a hard line. This hard line comes out in the driverside footwell behind the pedals. From there its the same flexible line to the cannister. From the canister to the motor it is the same thing in reverse. Since you do not have the stock air cleaner you are going to need to improvise a bit. If you have the pie plates, I think they come with a hole in them for the oil tank breather. You can get a PVC fitting and a rubber grommet to connect the return line to. This will be less contained than the original set up but the intake draw combined with the forced air nature of the system should work fine for your purposes.

[butzi73]

So is it a fire danger to not have a cannister if you have an enclosed garage?

[RWebb]

There is some danger. To me the main issue is that you have gas vapor potentially building up in the car's trunk....

...the battery & fuses are also in the trunk. So, even a tiny lil' ol' spark could cause some excitement - in a garage or not.

If the car is parked in an enclosed garage, then the risk is just that much worse.

[javadog]

Personally, I think that the biggest risk concerns the wrath of a wife or a serious girlfriend. I have found that they don't care much for the smell of gasoline, although they seem to not notice the smell of nail polish remover.

Tread carefully,

JR

[3.2 CAB]

I have seen several of these on various 911's and it really appears that most that actually leaked fuel, was when the tank was "topped off" some people that I know never fill to being actually full, because if they did, fuel would actually drip from the canister. Good luck!! Tony.

[RWebb]

If the canister EVER sees liquid fuel then something is wrong.

The charcoal canister will be ruined if it gets liquid gasoline in it. It is designed to deal with gas VAPOR, and will last for decades if that is all it sees.

[shawn911-slant]

what did they use for a expansion tank on a slant-nose?

[GotaT]

Originally Posted by Fast Corners

Well the one line to the cannister is a fabric braided rubber line (10mm I think). It connects on the fan shroud and travels down to the center tunnel where it connects to a hard line. This hard line comes out in the driverside footwell behind the pedals. From there its the same flexible line to the cannister. From the canister to the motor it is the same thing in reverse. Since you do not have the stock air cleaner you are going to need to improvise a bit. If you have the pie plates, I think they come with a hole in them for the oil tank breather. You can get a PVC fitting and a rubber grommet to connect the return line to. This will be less contained than the original set up but the intake draw combined with the forced air nature of the system should work fine for your purposes.

So then One line from the canister goes to the top of the Shroud
One other line goes from the Canister to the Air cleaners?
and one from the Tank to the Canister.

????????