General Rules About Fuel Systems? Lines inside the car?

So, I've been under the impression that it is frowned upon to have any gas or oil lines and cells exposed inside the car. I always thought a fuel cell had to have a firewall between it and the driver. However, I'm seeing a lot of cars with fuel cells mounted in the trunk in hatchbacks where there is no firewall...like Starlets for example. I had planned to mount mine under the car in the original tanks spot and run tubing for the filler up to the stock location.

So, here's the question--can I cut a hole in the rear floor, create a recessed box, and put the cell in the box with the top exposed for easy access or do I need to cover it with a firewall?

Per NHRA and IHRA rules you need it sealed from the passenger compartment. Not sure about SCCA.

I built a sealed enclosure around mine in the hatch with a hinged gasketed lid with latches for access/refueling

Every rule book I ever read said either a firewall, or enclosed in an additional steel box completely surrounding the cell. Can have an access panel. You might be seeing steel boxes with a separate internal cell, which meet this requirement.

Fuel lines in the passenger compartment are either completely banned or need some kind of specific protection. I know sometimes they are permitted with strict control over location and material, things like that.

A bulkhead someway somehow between drivers compartment and fuel cell compartment. No rubber hose for fuel running thru the drivers compartment. I always run a steel line with no connections thru the drivers compartment secured with cushion clamps. It safer inside than it is under the car. Make the threaded connections in the fuel cell compartment and the engine compartments thats are sealed from the drivers compartment. I usually end up with the fuel lines and the steel brake lines running on the passenger side of the tranny tunnel, where I can reach the brake bias adjuster. I run braided hoses back into the passenger compartment for fuel pressure gauge and the oil lines to the accusump.

Never run fuel lines in the drivers compartment. Very very bad idea. I may be safer for the fuel lines from minor bangs and bumps or the occasional off road excursion but exponentially more unsafe for the driver in more serious situations. Aka the big one.

A solid piece of metal line in the drivers compartment can and will deform in an impact and crack open. Game over!

SCCA rules used to (not sure of current rules) require that fuel and oil lines passing through the driver's compartment had to bulkheaded, encased in a steel tube, or be braided steel. My Challenge car is an old SCCA ITC car and it came with braided lines for fuel and for oil .The Accusump was mounted to the passenger area floor and fed the braided line . The fuel line passes through a rear bulkhead and the firewall with AN fittings.

Dirt track rules either prohibit or allow non material specific, MUST BE PAINTED RED. So some jaws of life happy fireman doesn't cut them.

I take offense to this as it is just as dangerous to cut the unmarked lines OUTSIDE the drivers compartment!

dean1484 wrote: A solid piece of metal line in the drivers compartment can and will deform in an impact and crack open. Game over!

Only if it is heavily rusted, which it will never be because it is inside the car.

Even 3/8 stainless line will bend into a U before it cracks. And stainless is so friggin' stiff that it is extremely hard to get a flare on without cracking it.

Typically have to be in a conduit / tube, or braided. Gives me the heebie jeebies, so I wouldn't .

When I ran the fuel line through the passenger compartment on the quad4 crx I put in a length of Emt first (with no junctions, a continuous piece) then put the steel line inside that. Under the car I just couldn't find a safe place.

FWIW, Subaru has run the brake and fuel lines inside the car since at least the mid-80s.

If steel lines inside the cockpit are good for the SCCA, then they are good for me. Thats why I always run a steel line thru the car. On my street cars I run aluminum tubes under the car.

I still lean towards running lines under the car. However, inside the car, does it have to be steel or braided steel or would something like Aeroquip's sockless hose work? It's extremely tough, flexible, and very unlikely to tear in an accident. 250psi. Textile braid reinforced.

I still lean towards running lines under the car.

I am most worried about the big one that has compartment intrusion and a line gets damaged. Yes lines externally run pose other problems but I rather deal with those than a fuel line in the car. It is just my personal way of building race cars.

Rusting of the line has nothing to do with it.

If you run the lines down the middle of the car, a collision hard enough to damage them won't be a problem because the crash will have already killed you.

In reply to Knurled:

In years past I would agree but with the ever evolving safety gear it is amazing what people walk away from these days. Really is a great thing.

Knurled wrote: If you run the lines down the middle of the car, a collision hard enough to damage them won't be a problem because the crash will have already killed you.

That would be the bonus automatic cremation function!

On our NASCAR cars the fuel line was a braided line inside the car inside a steel tube. I've never seen a car mangled bad enough to damage one. Any fuel fires would usually happen when the pump was knocked off the side of the engine block.

Nearly all of the cars I've seen built in the past few years all have a hard steel tube running through the passenger's side of the cockpit, painted red, with big labels saying FUEL LINE or DO NOT CUT. Seems like the smartest, safest place to put a fuel line to me, and many rule books agree. All of my rule books also state there needs to be a steel firewall in place at the front and the back of the driver's compartment that are sealed off completely