I was likely on a decent that a 60 does not belong....but with a full tank of gas and the angle of the downward slope....it was the magic combination for a water fountain of fuel. Anyway this was a unique situation in a way, but even then its not safe. I think most of the manual roll-over valves I've seen use some type of free-floating ball in a tube type of concept and when the angle changes to whatever it takes to move the ball...the ball moves and shuts off the vent which equates to stopping the liquid flow of fuel out the vent. I don't really know how effective these are but better to have one that not. And the fuel is not pressurized in the tank, so I follow the simple mechanical nature of that. From my limited inspection the roll over valve is simply a ball bearing (small) that sits in a tub) when the angle of the tube changes the ball rolls to the end and thats the "stop function" that shuts the vent, presumably when you are upside down, which so far I've been fine with not experiencing.
Yeah the 60 is a tank and not a bouncer...etc.
I'm not going to cap the vent hose at the firewall, unless I setup some other type of vent to ensure the fuel tank does not get pressurized. While its been some time since the engine swap, I'm sure this vent hose went to the charcoal canister (or evap tank), I'm not sure what Toyota called it off hand... that use to exist there near the passenger side frame rail off to the side of the I-6. That of course left the building some time ago, when the engine got swapped. I've never studied teh emissions stuff to much but in old days it was mainly vacuum stuff on the fuel vapor and now they have electrical switch etc that control some of the venting. I need to look into it further.
I was hoping to find some simple mechanical valve that would vent vapor but not liquid , that may be a fantasy but it sounded good. If not, I'm going to figure something out that combines likely some of the stuff from my OEM engine (5.7 vortec) or other combination of canister and potentially a rolloer over value , but I assume that anything in teh vapor vent business has to have a vent at the end , such that pressure is not trapped.
I have zero problem capping the vent at the firewall, but I've not thought of a solution with that approach, or if that makes sense in ease of approach. I know I could cap the firewall vent tube, and then do something back at the gas tank ...but I'm not really thinking about doing that.
Off hand I don't know what normal is...as to should I expect liquid fuel flow at the vent, but "my own logic" say yes... I don't know form years ago the charcoal canisters would get filled with fuel, and where there is fuel vapor..then its clear that can be liquid too...pending angle of fuel tank/vehicle....where the vent is in relationship to the tank etc.
Just trying to get to "the safe zone"
I understand that on descent of steep slope for extended period, the fuel tank becomes the high point of the fuel system and there-in lies part of the problem. This was very steep...and I would not have done it....other than others made it through and so here I go...along with full tank of gas. I'm sure I'm not the first one to see this, and I see a lot of comments about charcoal canisters etc (replacing them or installing new)..etc. Which I need to read through. The end problem.....is a saftey issue with liquid fuel coming out the fuel tank vent hose, where the fuel tank holds gallons of gas...and certainly a clear fire hazard.