+2 Fuel Tank Vent

[vincereynard]

A while ago there was a thread about fuel cap leaks (again).
viewtopic.php?f=40&t=30029

I mentioned that my car had a aero style cap that was (allegedly) leakproof. I had assumed it was
a cheapo far eastern Ebay thing. However looking on the inside it is one of these -
https://www.newton-equipment.com/aero-3 ... r-cap.html

Which is a bit of a result . British By George!

However scanning through the site I found specific fuel tank vents -
https://www.newton-equipment.com/tank-v ... range.html

Would one of these be a good idea instead of the "unique" wrapover tube thing.

[JonB]

Hi Vince

I'm not an expert but I've looked into tank venting improvements. I can't recall if your car has been modified in this regard or not (but you did mention it doesn't smell of fuel any more so I guess you have made alterations). From what I've read these valves allow the tank to vent under pressure (say, when parked in the sun) and when the engine is drawing fuel but don't let smelly vapour out except under extreme conditions.

If your car has the "club mod" with a single thinner vent pipe over the roof line and a second vent connected to a tail screwed into the filler, you may find you get even better stink reduction by fitting an inline valve to the remaining "over the roof" vent pipe. I've seen one of these installed behind the O/S B pillar trim, above the level of the tank. No idea how well it works in practice, but has to be better than Chunky's venting?

Thing is, you need the club mod first. I guess that if you were to install two of these valves in the factory vent pipes without adding the tank to filler tail connection, you might have difficulty filling the tank.

Your Pal
JonB

[mbell]

I believe at least one person on the forum has fitted one. I think it a sensible modification and probably a weight saving if you remove the hose over the roof.

As Jon said it does require the +2 breather mod to have been carried out first. If/when I revisit this area on my car I'll likely add one.

[vincereynard]

It was just for general information.
Toad stopped smelling much after I fixed the tank leak and fitted an electric fuel pump.

It seems to have a modded system as there is a pipe connected to the filler. Probably a Spyder mod.

[Chrispy]

I've done the basic change from the two big pipes over the top to just the small one, and tied into the filler neck. Worked well and greatly reduced the stench in the garage. The lovely Wife still complains about it, but with Carbs and no charcoal canister I can't see it every completely going away.

I did the MX5 NRV in the filler neck which worked like an absolute charm. I can now feel the tank all the way and not have fuel running down the side of the car when I turn right.

[JonB]

It seems to have a modded system as there is a pipe connected to the filler. Probably a Spyder mod.

Thought so.. then you're all set to fit a breather valve.

[Chris]

I fitted a Newton valve four about four years ago along with the sealed vent system. During which time it has given no problems. From November to April each year my car lives in a carcoon, and there is no trace of petrol fumes on removing the carcoon, go for it.

[Bigbaldybloke]

I?ve fitted two of those vent valves and the mod of a vent to the filler neck, but the car is not back on the road yet so can?t comment on how well it works in practice. No smells of fuel though in the garage with fuel in the tank. A couple of pictures attached, more posted previously on this subject some months ago. The vent pipes go into the rear pillar then out the original hole in the wheel arch without going over the roof.

[h20hamelan]

For me, the fuel cell was the way to go.
I have it working with a modern vented fuel cap which I altered to make work. Along with a one way fuel filler valve. I dont get fuel coming out around corners.
And the filler port is in the correct location, so not a true fuel cell. But its a quick six bolts if I choose to change it back to the cell.
I think it is a few liters smaller than the original +2 tank.