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gas tank venting

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I know this is an old topic. But I could not see the answer to my question in the former threads.
So here goes: I have a 1976 with the plastic fume separator in the trunk and a line that leads to the front of the car to where the canister use to be...
I know the earlier cars simply vented the fumes to the air via a small hole in the trunk behind the license plate.

My question: Is there any advantage to leaving the  "fume separator" in the trunk and venting that to the air. Or is it best to simply run a line from the tank (filler neck) to the outside like the earlier cars.

My thought is not creating a vacuum in the tank while minimizing fumes in the garage where it is parked. Just not sure if leaving the separator would actually do any good.

Any thoughts on this? How did you guys do it?

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I have a 72, and the separator tank under hat tray was deleted and the gas tank/filler tube is vented thru the trunk (Euro style) I have no issues with fumes in an enclosed garage....(touching wood)

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I know this is an old topic. But I could not see the answer to my question in the former threads.
So here goes: I have a 1976 with the plastic fume separator in the trunk and a line that leads to the front of the car to where the canister use to be...
I know the earlier cars simply vented the fumes to the air via a small hole in the trunk behind the license plate.
My question: Is there any advantage to leaving the  "fume separator" in the trunk and venting that to the air. Or is it best to simply run a line from the tank (filler neck) to the outside like the earlier cars.
My thought is not creating a vacuum in the tank while minimizing fumes in the garage where it is parked. Just not sure if leaving the separator would actually do any good.
Any thoughts on this? How did you guys do it?
I still have the separator tank on my '70 and routing the fume line to the carb. The fume in the cabin is now from the exhaust leak at the mid-pipe to down-pipe flange.

Sent from my SAMSUNG-SM-G935A using Tapatalk

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Hi,

 

I look at it this way - emissions and safety.  I've kind of taken the middle path in that the charcoal canister is in place and plumbed to the tank, but the other end is not connected to the carb.  Seems to work to keep the smell of gas away.

 

Venting through the trunk will work but I always worry about releasing fumes in a garage that has potential ignition sources.  Did the early cars run the vent line from the filler neck or from the expansion tank?  If directly from the filler neck, could gas overflow when filling the tank?

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Along these lines, I wonder if there is a modern smaller inline charcoal filter to put in the trunk between the tank and the atmosphere?
 

It appears the older vent tube was located at the top of the filler neck and simply ran along the trunk wall to a hole in the floor. Similar to my old Porsche. I will have a look at the Porsche tomorrow to see how they make it work.
 

(Healey 3000 ! We need to talk. I am shopping a Healey myself... 😉 

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31 minutes ago, Moto Carlo said:

Along these lines, I wonder if there is a modern smaller inline charcoal filter to put in the trunk between the tank and the atmosphere?
 

It appears the older vent tube was located at the top of the filler neck and simply ran along the trunk wall to a hole in the floor. Similar to my old Porsche. I will have a look at the Porsche tomorrow to see how they make it work.
 

(Healey 3000 ! We need to talk. I am shopping a Healey myself... 😉 

Hi,

 

The canisters I've seen are pretty similar in size.  Essentially, the needed volume of charcoal is probably a function of tank volume (or fuel surface area), so most cars may need a larger canister.  I've been eyeing the e36 canister, which is located in the spare tire well.  I think I had posted about a Nissan canister that is similarly flat but has nice mounting flanges.  I was planning on bolting it to the parcel shelf underside, next to the expansion tank.

 

Sent you a PM...

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2 hours ago, Moto Carlo said:

My question: Is there any advantage to leaving the  "fume separator" in the trunk and venting that to the air. Or is it best to simply run a line from the tank (filler neck) to the outside like the earlier cars.

My thought is not creating a vacuum in the tank while minimizing fumes in the garage where it is parked. Just not sure if leaving the separator would actually do any good.

Any thoughts on this? How did you guys do it?

 

So earlier cars vented fume to atmosphere and at some point in time engineers come up with charcoal canister in engine bay........

unless you believe there is no global warming then can do whatever you like, but stop and think about these car from 68-76, every so often they designed something different/ new to improve these cars inclusive of reducing emissions. 

Long story short, I would find me a canister for engine bay and the bracket. To me that is the best route. No fume smell in the closed space plus you get better gas mileage 😊

i have mine set up as such and there is issue whatsoever. I also have fuel return valve in engine bay and every since I had it installed there is no gasoline smell in the engine bay either.

long reply but I have every bit of intention to revert back the way engineers figured should be 40+ years ago

 

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(edited)
21 minutes ago, Moto Carlo said:

3000, do you happen to remember the Nissan model year? That sounds like a good option.

No, I'll have to do a search for "Nissan" and "canister".  I hope that works...

 

EDIT: Found it, https://www.bmw2002faq.com/forums/topic/232248-relocation-and-upgrade-of-the-charcoal-canister/?tab=comments#comment-1299855

Edited by Healey3000

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Why could I not find it? Thanks man.

 

The Porsche did it like the earlier e10s. Simply a fitting at the top of the gas filler neck and a hose that runs to the atmosphere.
I plan to use the existing separator ,then the charcoal canister then let that vent to the atmosphere. 

 

Thanks again everyone!!

 

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A charcoal canister needs fresh air purging or the charcoal eventually loads up and cannot absorb any more hydrocarbons and becomes ineffective.  A factory install sucks from the canister and fresh air is admitted thru a third connection to atmosphere.   This is how it works on all factory cars with a charcoal canister.  If it is not purged, sooner or later it will be a dead duck.

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In this photo, you can see the little tube that the vent line attaches to.  It is brazed onto the side of the tube that the valve cover breather uses.

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I plumbed the line running up to the engine bay into the air cleaner, so the fumes can be burned.  The charcoal canister was already gone when I got my car.  I eliminated the grey plastic expansion box in the trunk and have not noticed any adverse effects.

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What would be recommended for a ‘72 tii. The brackets below the hat shelf for the vapor canister were removed, so I vented directly from fuel tank to outside. Yes, lots of gas odor in garage. 

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