II Much Vent System install problem

[dhutton]

SAE 30 R14 will outgas fuel vapor if its used with compatible fuels, and it will degrade and outgas even more vapor if its not. Generally speaking, anything thats advertised as fuel line but is flexible is going to outgas and degrade to some degree depending on the fuel used. Fuel tank venting is obviously a low pressure application, so its tempting to go the inexpensive route in this area -- this can be problematic if controlling odor is a concern, and it can be dangerous if the vent system is installed inside the vehicle in terms of toxic exposure to gasoline fumes and fire risk. I would not use anything but steel hard lines or PTFE conductive core. Adapting to the nipple/barb is problematic in some cases as the industry really hasn't standardized in this area. Currently I see the gamut of SAE O-Ring Ports, SAE Quick Connect, NPT, various plain steel tubing diameters, all of which require a different method to convert to PTFE or hard line. Flexible rubber type hose is very attractive given this, but should be avoided.

Hose suppliers are increasingly listing SAE specs, but don't typically explain them. This is a problem as most parts of the US are going to have fuels that have 10% or more of ethanal or other additives and this may increase to 15% with recently announced changes by the president. If you look up the SAE standard you will find hose like Carl pointed to will outgas with 5% additive even though its meets the criteria. The utility of the hose will rapidly degrades at 10% or higher additives -- see below. There is a LOT going on with respect to modern fuels and their effects on vintage cars. I'll be writing about this on the II MUCH Blog.

"Hose which may be supplied either coupled or uncoupled for use with gasoline, diesel fuel, lubrication oil, or the vapor
present in either the fuel system or in the crankcase of internal combustion engines in small engine applications. Exposure of these hoses to gasoline or diesel fuel which contain high levels, greater than 5% by volume, of oxygenates, i.e., ethanol, methanol, or MTBE (methyl tertiary butyl ether), may result in significantly higher permeation rates than those listed for 30R14. "

Holley Vaporgard hose does not outgas in my experience. It has a liner and is a lot more flexible than Teflon hose. Great product imho and has a nice OEM look.

Don