vapour separator
i want to fit a proper breather system to the fuel tank on an 84 xjs. i have

a racing 2 way breather to fit into a breather pipe that goes straight to atmosphere that opens when negative pressure of 0.08 Psi (0.0055 Bar) is reached. If the tank should become pressurised then the valve will open to vent if the pressure reaches 0.725 Psi so when i discard the charcoal filter which is in the r.h. rear wheel arch i will have the choice of 3 redundant pipes,

can any of you racing guys remember which pipe is best for this?

 

Does not matter. But best to choose the highest outlet on the tank. To check it is clear, put a pipe on it, tape over the others, open the filler cap and blow.

Just in case you are unclear on the setup after the VS, it is like this, as it is maybe best not to vent the new valve into the boot! On UK spec cars the output from the vapour separator goes through a Rochester valve (small black 1.5 inch diameter) which is further into the tank recess/RH wheelarch behind the vapour separator, easier to see once the VS is removed. The output pipe from the VS connects to this valve which is the factory version of what you have just bought. This Rochester valve goes into a long thin metal pipe that runs across the floor at the back of the tank and out to vent below the car, just in front of the cage on the UK passenger side. If this pipe is clear, or can be cleared, hooking up your new valve to it is a good plan.

The pipe can be seen easily in this photo:



Greg

 

thank you greg, thats exactly what i needed to know,
rgp