Help - Search - Members - Calendar
Full Version: Venting of the fuel tank charcoal filter with carbs - Where
914World.com > The 914 Forums > 914World Garage
jjs3rd914
Just finishing a 2056 build with weber 40's.

With the D-jet FI system on our 1972 there is a hose that came from an output nipple on the passenger side of the fan housing to input of the charcoal canister in the front trunk. The output return line from the canister plugged into the air cleaner. This system blew air from the fan housing thru the canister and I believe sucked the vapor out of the tank routing it back to the air cleaner.

So with the carb conversion I would still like to vent the fuel tank vapors but where would be the place to do it?

We could modify one of the new air cleaners and place the return line there, or maybe put a vent in each air cleaner and vent into both with a tee.

Or just it safely somewhere to atmosphere.

O I suppose eliminate the charcoal canister altogether, but then how does the fuel tank get vented?

What have all of you done with this with the carb conversion.

Thanks

jjs3rd914

bbrock
QUOTE(jjs3rd914 @ Nov 9 2018, 03:47 PM) *


We could modify one of the new air cleaners and place the return line there, or maybe put a vent in each air cleaner and vent into both with a tee.



Either of these. The idea is to burn the vapor to reduce pollution. Removing the canister creates a lot of stinky gas fumes for you to breath. Just route the hose that went to the air box to one or both filters on the carbs. beerchug.gif
SirAndy
QUOTE(bbrock @ Nov 9 2018, 03:58 PM) *
QUOTE(jjs3rd914 @ Nov 9 2018, 03:47 PM) *

We could modify one of the new air cleaners and place the return line there, or maybe put a vent in each air cleaner and vent into both with a tee.

Either of these. The idea is to burn the vapor to reduce pollution. Removing the canister creates a lot of stinky gas fumes for you to breath. Just route the hose that went to the air box to one or both filters on the carbs. beerchug.gif

agree.gif

I removed my charcoal canister many, many moons ago and that is one of the few things i regret every time i go on a twisty drive.
icon8.gif
IronHillRestorations
Fuel vapor recovery has benefits and zero downsides. The fan on the engine provides positive air pressure and the engine intake is the suction.

Unless you like the smell of gas.
jjs3rd914
Done deal,

We will vent the fuel vapors into the carb air cleaners. So as to not favor one carb over the other we will use a tee and vent to both..

So this adds another question.

Does the fuel vapor actually affect the air fuel mixture. In order words do the carbs now have to be re-adjusted to compensate for air that already has some fuel vapor in it. The car seems to run terrific during initial test runs. So we will check after the mod and adjust accordingly

Thanks for all the advise.

jjs3rd914
IronHillRestorations
Not worth the time and trouble to route the vapor lines to both carbs, IMHO, I don’t
Literati914
QUOTE(jjs3rd914 @ Nov 10 2018, 10:36 AM) *

We will vent the fuel vapors into the carb air cleaners.So as to not favor one carb over the other we will use a tee and vent to both..

jjs3rd914


Anyone got a descent pic of dual idf's with such a set up? I'd like to see how people have addressed this. Are we adding fittings to the top hat/cover or from underneith?
jjs3rd914
Here is what we are trying to do. But it does look like even without the added nipple on top of the air cleaner that the rain tray will not clear any more. Ours is off while we are doing the conversion.

Have other carb conversions found that the rain tray has to be removed??

For sure it look like rain tray will interfere with the vent hose even with the right angle adapter.

Thanks

jjs3rd914


Click to view attachment Click to view attachment
bbrock
QUOTE(Literati914 @ Nov 10 2018, 10:36 AM) *

QUOTE(jjs3rd914 @ Nov 10 2018, 10:36 AM) *

We will vent the fuel vapors into the carb air cleaners.So as to not favor one carb over the other we will use a tee and vent to both..

jjs3rd914


Anyone got a descent pic of dual idf's with such a set up? I'd like to see how people have addressed this. Are we adding fittings to the top hat/cover or from underneith?


The kit I bought from the old Automotion 30 years ago included plastic bulkhead elbows for attaching the vent and vapor hoses. I put mine underneath.
Literati914
chowtime.gif
https://vwparts.aircooled.net/Classic-Style...r-idf-bk-90.htm

I want these.. but then again, I would prefer a vent under the bottom of the filter area if possiblle.
aharder
QUOTE(Literati914 @ Nov 10 2018, 04:57 PM) *

chowtime.gif
https://vwparts.aircooled.net/Classic-Style...r-idf-bk-90.htm

I want these.. but then again, I would prefer a vent under the bottom of the filter area if possiblle.


Those do look very nice but @ $159 ea blink.gif
rhodyguy
$159 a pop and NO filter elements. That's extra. Expensive conversation starter.
Mark Henry
On a T3 I took an inch or so wide sheet metal, dimpled it bit (sockets and vice), drilled a hole and folded the two top/bottom ends the height of the air filter.
Added a nipple, put it on the outside of the filter and the top/bottom covers held it in place when bolted down.
I also folded the sides inwards and these stuck into the filter pleats. very solid when all done.

Breather works through the filter, you don't have to cut a hole into the filter.
Literati914
I'd like to go more stealthy and just add a male 90 degree barbed elbow hose fitting on the under side of the IDF's filter base plate... My car's at off site storage (or I'd look), does anyone know what the return line's inside diameter is?
jjs3rd914
Im not sure where one would put a hose attachment under the carb base plate. On mine at least sure does not look like any room.

Look the the pics i posted

Thanks

jjs3rd914
IronHillRestorations
Yea, I don't know how you'd do it to the base plate. Plenty of room on the top
Literati914
QUOTE(bbrock @ Nov 10 2018, 01:56 PM) *


The kit I bought from the old Automotion 30 years ago included plastic bulkhead elbows for attaching the vent and vapor hoses. I put mine underneath.


My first 914 had a single weber and I was too young to know better on the venting (but I do remember it's strong fuel smell)... my second 914 was CIS injection on a /6 ... so I have no experience with the Dual Weber idf's set up for my /4 and they're being kept in storage ATM. So the above quote is why I was thinking underneith would be my choice. So, absolutely no space under there for a tiny fitting? That one on top looks big to my eyes btw.
jjs3rd914
The fitting we put on top of each air cleaner is the same size as what was originally on the D-Jet air cleaner. The very same hose that attached to the D-Jet air cleaner is what you see in the picture.

I do like the idea of a small fitting under each one but it indeed would have to be fairly small and favor one side of the plate. Not sure with small fittings it would choke off the venting flow.

We still have not installed the engine lid, still test driving, and it does seem there is no way it will close with the rain tray. Not even sure it would close even with the new nipple vents removed.

Again no one yet has replied if the rain tray has to be removed with this conversion and air cleaner setup.

Thanks

jjs3rd914
bbrock
I had to fish one of my carbs out of a storage box to make sure I was remembering right that I could mount hose nipples on the bottom side. Yep, plenty of real estate to mount fittings under there. These were in an old Weltmeister kit I bought from the old Automotion in the 80s. The housings are K&N and measure 9"x5.25". I wonder if they are still available.

Click to view attachment

Click to view attachment
jjs3rd914
QUOTE(bbrock @ Nov 12 2018, 07:39 PM) *

I had to fish one of my carbs out of a storage box to make sure I was remembering right that I could mount hose nipples on the bottom side. Yep, plenty of real estate to mount fittings under there. These were in an old Weltmeister kit I bought from the old Automotion in the 80s. The housings are K&N and measure 9"x5.25". I wonder if they are still available.

Click to view attachment

Click to view attachment



The housings in my picture/application are 7-1/2" by 4-1/2". Just almost too small for underneath attachments. But we will sure investigate when the engine lid/rain tray gets installed.

Carbs and air cleaners bought from AA performance in CA.
Linkage we made ourselves.
This is a "lo-fi" version of our main content. To view the full version with more information, formatting and images, please click here.
Invision Power Board © 2001-2024 Invision Power Services, Inc.