I don't love the smell of gasoline in the morning.

I'm having a problem with fuel spilling out the breather tube on the gas tank when I make a hard left turn.

I've got a Fiberfab and the tank is done like the manual describes; a breather tube attached to the side of a short filler tube on the top of the tank (see pages 60 & 61 of the Faberfab manual in the library). There is a piece of fuel line attached to that runs down the inside of the fender.

Is there some sort of check valve that can be installed to prevent the fuel spillage?

-Paul

Regardless of those ancient directions, if you have your breather tube running to a point lower than the tank, and any fuel makes it into that tube, you run the risk of creating a syphon and you'll end up . . . possibly . . . maybe . . . . one day . . . . draining your entire tank!

"syphon
n : a tube running from the liquid in a vessel to a lower level
outside the vessel so that atmospheric pressure forces
the liquid through the tube [syn: siphon]"

Run the breather up OVER the tank and filler neck, into a plastic breather/filter from a 72 and up Super Beetle, and then fix a line back to a vac port on the/one of the intake manifolds.

Do it right! Quit fooling around, that vapor is dangerous ! ! !

Luck!

TC

Vintage sells a one way "check valve" that allows air to get into the tank but supposedly prevents fuel from sloshing out. I think it was about $15. Incidently, I discovered that the one installed in my 2000 VS was installed backwards. Hmmmmmmm.
Hoss

Paul,

When I first got my Speedster I had the same problem.

One of the other owners gave me the answer.

Pick up about 6'of Fuel Line. Attach one end to the Vent ferrel a fuel Tank Filler. Loop the Fuel line so the upper portion of the loop is higher then the fuel tank. I Wire Tied the Loop so it did not unloop itself or change height being higher then the highest point of the fuel tank. Feed the remainder of fuel line from the "Loop" out the Bonnett down extending out of the vehicle (Mine enters the R/F Fender and extends under vehicle.) Secure the vent hose so it doesn't contact R/F Suspension/Steering.

Project complete.

Haven't had fuel Smell Since except if I spill fuel when fueling vehicle.

Give this a try.

Good Luck,

Jack

The check valve in question can be purchased in a Auto Parts Store "Help Rack" for $4

Alan's got it right, when I got my first Vintage, I called Kirk about the smell. He said they used a simple check valve. I checked by blowing and sucking on mine. It allowed vapor through both directions. Therefore it was faulty. He said he would send me one no charge and that they were available at any parts store. Since I was on my way to the auto parts store for my wife's car anyway, I picked one up for something like $2.99. It was one of those universal "HELP" parts in the red shrink package. Called Kirk and told him not to mail it.

-=theron

Thanks,

I'll give the check valve a try.

-Paul

How does the check valve work in this instance? I know how a check valve is supposed to work, but should any fuel eventually find it's way down the tube so as to make the check valve necessary (to prevent leakage) the pressure/weight of the fuel in the down/drain tube will also prevent the check valve from working . . . as a check valve.

Essentially, it'll no longer act as a tank vent, rather it'll just become a plug to keep the fuel in the drain from leaking out.

I'm sure that the loop does a good job of keeping the fuel from making it's way to the drain/down tube, but that check valve at the end seems like a the wrong thing to stick there. If it does it's job in providing a one-way flow (air in) it's also preventing the fuel from coming out.

No leak, but no venting either.

Please explain, 'cause the check valve is SO easy that I really want to use one, but . . .

My breather Tube goes to a small plastic collector bottle and then through a metal pipe from there out through the front. Never had a problem with that. Should I take a pic?

TC, the check valve I used was a tiny little plastic canister, about the diameter of a quarter with an inlet and outlet sized for the rubber tubing that came out through the gas tank breather orifice. Within the cannister is a small plastic diaphragm which effectively (?) closes the outlet side as pressure increases on the inlet side. On the outlet side is another length of tubing which ran down the inside of the body to into the front wheel well area.

It worked fairly well, but I still occasionally had gas fumes, probably from the gas tank cap; I believe it may have needed a new gasket. Gas fumes readily enter the cockpit area on some replicas if the trunk hinges go through the firewall, as they did on my VS. Also, fumes in the trunk area, the same place that the battery resides, is not such a good thing. JMHO
Hoss

And here I thought that I had the only speedster that had the vapor on the left hand turn problem. Drove me nuts. I only have a 6 gallon tank anyway and when I would fill it, it seemed that ANY turn created the gas smell. Thanks for the solution. My new check valve is in the mail. As H. Simpson would say, "Doh!"

Gary

Thanks guys! I'm gonna try one ! ! !

"How does it go in the Ghia? "

On a stock Ghia, it's sort of clever. All of the vent hoses go into a charcoal canister mounted above the tank on the inside fender well. then to a hose and hard line back to the engine compartment and then back to a rubber line into the air cleaner.

The carb vacuum sucks the vapor from the tank through the canister, line,and air cleaner into the engine, it's a closed system which eliminates vapor and acts in a way like a PCV valve, but for the tank instead.

I wanted to duplicate this system for the 356, but it has the stock Pre-A Porsche gas tank which is sort of a rare/expensive item and I didn't want to drill and tap for vent barbs. I MAY vent the tank at the filler hose and try the Ghia system or use the check valve idea that 's being discussed here. I'm still waiting to get it back from the shop with the new racing suspension and transaxle, so the tank venting is all speculation and pre-planning right now.

TC: What year Ghia R we talking? It may be just a tad to "new". I'm interested in pre-pollution control cars. I'm toying with just running the line into a canister and then on out of the car.
Hoss just got a '63 Bug. Maybe we'll get some insight on that one.

BD

The Ghia is a '68. VW introduced all that pollution control stuff around '67 or '68, I think. But then again, I don't remember much anymore . . .

On the '63 bug the breather line makes a big loop and then feeds down through the tire well. There is no check valve installed on it, but that may be a worthy addition. I'll stay tuned to hear other ideas. One thing is for certain; I'm not going to pay no fifteen bucks for a check valve!
Hoss

Well, I guess I'll play Devil's advocate on this one. I've had the same smelly problem as all of us had . I bought a check valve and thought I had the problem licked. Like Hoss, I still had fumes once in a while. Duh, yeah, it was seeping/leaking at the gas cap. Ever open up that gas can that sat out in the sun and get blasted with the pressure escaping? Well...same deal with our tanks, fellas. I feel these check valves are pressurizing the tanks when out in the hot.I can't say how much pressure builds up in there,(read boom!) but I do know it's enough to force it out past my gas cap, and my gas cap is tight as heck and hard to get on and off. I've often wondered if those with troublesome leaky gauge senders might have been caused by this. The tank vent I feel is supposed to do just that...vent... in both directions to relieve expansion and contraction. I've read that the VW Bug vent hose ran down to the front of the trunk and outside. I nixed the check valve and ran my line up and over the hood hinge then down and out a hole to the fenderwell and down to the bottom of the pan. I wire tied the end of the hose to the support thingy that the brake line attaches to. So far I have yet to smell any gas fumes and it is again dry around my gas cap.
Do any of the builders put check valves in their new cars as a practice or is it the end users putting them in?

Hoss: if you could, see where the vent line goes on your new baby.
TC: How does it go in the Ghia?

BD

Here's my little bottle and tube....works well.

what way is that valve supposed to be facing? i often smell gas fumes...

To confirm that you are installing it correctly , suck on it ..you'll get air , if not turn it around, repaet and you'll then have air...That side of the valve goes toward the tank.....so that the air can travel in to elimate a vacuum ... the valve also blocks the fumes and or fuel from escaping.

anyone have a photo of a properly installed valve on a v.s.? i'd rather not cut the line to suck on it, unless i have to.

George, from what I remember, the picture would probably not help. The valve that came with my VS looked right either way unless you look at it VERY closely. Function testing is the best way. Be careful, you don't want to swallow even a little bit of gas!

When I ordered my valve I was told that there was a dark side and a light side (no star wars jokes please Luke). The dark side should be place on the fuel tank side. Just thought it might help.

Gary

Gary, it must depend on whose product it is. Mine, both the original and the replacement was an opaque plastic, both sides the same. When I opened it up, one side had little fins on one side near the outlet that prevented the diaphragm from seating when the flow was in that side's direction. The other side had no fins, so the diaphragm would close the outlet.

Valve came in the mail. One side black, the other side clear. Checked the flow and the black side definitely went to the tank side. I discovered that I had no valve at all in the old configuration. Plus, the overflow hose was only about a foot long. So when I got gas going out it was probably running down the wheelwell. Ack! Anyway I had some tubing on hand and fixed that part. Five minutes later the new valve was in place and I was on the test road. Worked like a charm. Best $15 solution I ever had.

That check valve is called a "roll-over" valve. It is MANDATORY unless you enjoy the thought of burning to death. No matter how you route the hose, there is a way your car can end-up (or end-down) that will have the tank draining out the vent line. The vent line should run to a fuel filter to keep dirt from being drawn into the tank, and then through the roll-over valve and then outside the vehicle (away from the exhaust pipe for the engine or gas-heater. Modern (post 1970) cars use a charcoal canister to collect the vented fumes and then they draw them into the top of the carb and burn them at startup. There is usually a vaucum or electric valve in this situation to avoid sucking gas fumes out of the tank while the engine is running. Really modern cars have a series of purge valves on the tank and a tank pressure sensor to control both the pressure in the tank (and only vent what is needed) and monitor for loose gas caps or other leaks in the vapor system (like holes in the filler neck).

For the roll-over valve to work, it should be oriented so that the valve is open by its own weight when the car is upright and closed when the car laying on its side with the tank above the open-end of the vent hose. As far as this valve blocking the flow of vapors out of the tank, that would be a mistake as the expanding fuel has to go somewhere. If you allow pressure to build in the tank (on a hot day after a fillup?) the fuel line to the engine will be pressurized and can overcome the float pressure (6psi max) and cause a flow of gas into the engine, leaking past the rings and into the crankcase. This leads to many possible outcomes, none good.

Bottom line:
All speedsters that are driven (even around the block) must have this valve. If you don't like smelling fumes turning, imagine how much you will hate it when you are stuck in the car, upside down, smelling the fumes.

Gary:

Who did you order your check valve? I have had gone to several parts stores, they all know what I am talking about, but no one has them. Could you please let me know where you ordered yours? I do have a strong gas smell after a long drive, and I can see fuel in the hose coming off the gas cap relief valve and it is leaking in the right fender after drives. I am concerned my garage may go up in flames with all the strong fumes.

Thanks

Oz

Hi Oz,
Got mine from Vintage. Called on the phone, it was in the mail that day. Fifteen smakeroos and your nose will not know when you turn left any more.

Gary

Thanks, I will give John a call.

Oz