I was wondering if it’s necessary to run a metal line from pump to carb?

 

Yes.

 

Yes. Unless you like fires.

 

Lmao

 

Pump,,,, filter,,,, carb.

 

I'm curious why this is; what happens to a rubber line on top of the engine that doesn't happen at the tank or chassis to pump connections? Not disagreeing with the advice, just wondering.

 

No its not an absolute. Rubber fuel hose made for gas is readily available. How its installed is another matter. I use braided fuel line. Imo, it looks better than steel or rubber lines.

 

The fuel pump pressurizes the fuel. Pressure between pump and carb, not between tank and pump.

 

Let’s qualify the YES answer alittle more. The reason you want a hard line is if a V belt flies off or breaks. It’s not outside the realm of possibility that the V belt flies into said rubber line and either breaks said line or tears it off the due filter/carb/fuel pump. When this happens you now has the possibility of fuel spraying onto a hot exhaust manifold//header, and I’m sure you can figure out why that’s undesired.

Now the other question. How often does this happen? Not very if your accessory drive is maintained right. In fact there were 1000s of cars running around setup with just a rubber hose for decades (by legit mechanics too) and it wasn’t a prolific issue by any means. But it happens, that’s why the OE lines were hard lines. Pulling a rubber hose would have been way cheaper and easier during manufacturing than forming steel lines. They did it for a reason.

With all this said, if you take the car out for a little joy ride and the v belt goes flying and tears up the rubber fuel hose you care to hedge your bets on following:
1. It misses the rubber line
2. By some miracle it hits the line but doesn’t break it.
3. Hope you can get the fire out with your on board extinguisher (if you have one)
4. Hope everything happens right in front of a fire station and the fire company guys are feeling particularly “gentle” that day. I work with public safety folks and in particular two of my coworkers are volunteer firemen and I can tell you this from my conversations with them. If the car catches fire you better open the hood before they get there. If you don’t they are gonna chop the front clip off the car with a halligan tool and Fireman’s axe. They still might anyways. There will likely be zero f%*ks given.

Bottom line, unless you’re testing something or it’s an emergency repair you should have a hard line.

 

I like the braided fuel line as well. It can be routed along the OEM steel line route so as to be out of danger should a belt break. It's still rubber inside, high quality rubber, rated for much more PSI than the pump can develop. Doubt that the technology for the quality of rubber lines (or it was cheaper if it did) you can get now existed during the life of the C3. Low pressure rubber lines are significantly different from high psi hydraulic or fuel injected lines.

 

I've also had the fan belt and A/C belt let go within minutes of each other on I-90 in Montana at 10 PM. Zero damage to anything. But it was pretty lonely out there! My cars insured. Let it burn. Collect agreed value insurance. Buy another C3. 1000's out there to choose from. Or buy a boat.

 

I only started this thread out of curiosity. I’m replacing the pump and I do have a fairly new metal line already in place but it can be a pain threading the line on the pump fitting. I guess that’s easier than putting out flames!
Thanks for all the input. That’s why I love the forum. All stupid questions answered 🤣🤣

 

I have tried a different path for my fuel lines on a 1968 C3.

Using SS Braided Hose with PTFE liner coming out of the tank up the rails and over the bell housing and into the EFI system's throttle body. My idea was to try a different route where the fuel lines are less susceptible to damage and try to keep the fuel cooler at the same time. The SS braided lines are enclosed in a DEI insulation tube cover and then for the last 8 feet I have a fire proof sleeve over the fuel lines and they are secured ever few inches. The fuel lines are nowhere near anything Hot or moving, if I blew My clutch or Bell Housing apart there might be some problems.

Is there any reason I have not thought of NOT top do this?
The fuel never gets heated up by the Radiator or the engine and arrives at the throttle body the same temperature as the fuel in the fuel tank. I have high compression so I am trying to keep the air entering the combustion chambers and the fuel just a bit cooler in search of more power. Cooler fuel is denser fuel....

One more thing, having a glass lens on the pressure gauge permanently mounted on your engine is not a good idea. If something were to break it would be spraying pressurized fuel which can vaporize VERY quickly. A great setup for having a weenie roast.

I remove the Fuel Pressure Gauge after finishing the setup/learning mode or if you really want to keep it put a valve behind it so you can shut it off.

 

EFI on a 1968? I didn't think of that.