Gasy

The rally FX being all race has slowly been loosing extraneous things. One of the more recent things I did was remove the charcoal canister. It’s not needed for the car to run, however removing it and capping the line from the gas tank that used to go to it causes some issues. What happens is that modern fuel systems are sealed. The gas tank cap holds pressure as a limited one way valve. As you use up fuel, that would create a vacuum in your tank and make it hard for the pump to work, so the gas cap has a one way valve to let air in. But as things warm up, vapors in the tank expand and cause the tank to become pressurized. Normally these excess vapors are routed into the charcoal canister to be absorbed until they can be put back into the intake and burned off. Without the canister pressure builds until the safety release in the cap opens, which is enough pressure to also cause liquid gasoline to come puking back out the cap.

I poked around the Net to see what others’ solutions were. Some would simply leave the vapor line that used to go to the canister open, maybe capping with a breather filter. Others would source an old school gas cap that doesn’t hold pressure, but that’s hard to find now, and probably extremely hard to find one to fit an unleaded import car. So some people would just drill a small hole in the gas cap. Pretty caveman and kind of bothers the Clyde Frog in me.

I could put everything back, but there must be a way. Finally stumbled across in some random automotive forum, someone posted a link to these valves sold by Fuel Safe Racing Cells. The TPV8 is the larger red anodized device, a “Tank Vent Pressure Release Valve”. It’s designed specifically to be shut at static state. It opens under light vacuum when fuel is being pumped out, .08 psi vacuum. It also opens when there’s pressure caused by the tank warming up, but much less than the gas cap safety at .725 positive psi. This looked like the ticket, but also a pretty penny! But hey, it’s pretty anodized aluminum, and made in USA.

Browsing the catalog, I found the smaller device, it’s the TRL7 “In line tank vent valve” with rollover protection. Apparently many motorsports sanctioning bodies actually require these, it’s a valve with a little ball bearing rattling around in it. As long as the body is kept right side up, it’s open, but if it tips beyond horizontal the ball slides over and shuts the valve off, preventing gasoline from leaking out the vent. I don’t plan on ever being upside down but I decided to be really Safety Frog and install one despite the additional cost.

To finish off my plans I spun by Ron’s and found they had in stock the K&N filter that would fit just right. As a bonus, much to my surprise, I discovered that it was also made in USA. While I was there I got some fuel hose, although they didn’t have the bulk hose in the size I wanted. Instead ended up with a short section of fuel injection hose. Overkill as this hose shouldn’t be seeing any gasoline, but heck, it’s also made in USA and I didn’t need to go to another shop. It ends up that everything but the two clamp thingies are made in USA, I’m pretty sure Breeze hose clamps are USA. The clampy things I got to hold the valves have no labeled country of origin.

So I’m spending a good amount of coin for this seemingly pretty insignificant thing, but I can feel good to support USA manufacturing industry and the parts are high quality.

I’ll need to install, but it should be pretty simple.