Running the Gas Line

On my 1954 Cdn Pontiac, I ran the gas line from the tank to the front of the frame. One thing I noted when I took off the line adapter at the tank was that there is a severe restriction in the adapter and size of the opening in the tank itself. I ran 5/16" line because that's what fit the adapter. The adapter steps down the line to fit the gas tank fitting. The gas tank fitting seems to be 1/4" or less in size. If you are planning on running a high pressure fuel system, you probably want to look at the fuel outlet fitting on any original tank. Might be a source of fuel starvation!

The first thing that I did was plan the complete path of the fuel line. It was actually pretty easy cause I just went down the passenger's frame rail. I planned on using one 5/16" line, 13 feet long, double flared at the gas tank and bent to follow the frame rail to the front. I have a top hat style rail and the bottom of the top hat will protect the gas line.

I practiced double flaring with a kit I got from the local parts supplier. I shopped around and found kits that were anywhere from $20 to $80 and price had nothing to do with quality! I found a life time guaranteed kit with instructions (quite a few didn't have any!) for $32. I used up about a foot of line practising. I used a proper pipe cutter to cut the line not a saw! A saw will leave filings in the line - just what your engine doesn't want!

Flaring tool

Double flare tool

I bought a lever action pipe bender ($10 on sale) and used up another 2 feet practising bends. The first bend, I put in the wrong groove and it promptly kinked the line. After the third bend and the right groove I felt pretty comfortable. I strongly advise that you purchase one of these tools, they are dynamite and you can bend the line to exactly any degree that you want.

Tube bender

Tube Bender

Next, came straightening out the 16' of line that I bought. It was coiled up - I had to stop the parts guy from coiling it into tight coils! That would of meant lots of time uncoiling it. I asked him to coil it up in large circles 3' diameter. You straighten the line by slowly and gently working it by hand.

I followed some advice and bent a coat hanger to the shape of the line from the tank to the rail, leaving a few extra inches at the gas tank so I can fix it in case the double flare leaks. After getting out from under the car and looking at the bent coat hanger, I was shocked! I couldn't believe that this was the correct shape. Under the car, I went and verified that yes it was the right shape! I was totally disoriented to the shape that was required when I was standing up versus when I was under the car and looking up. I highly recommend using the coat hanger trick.

I put on the fitting and double-flared the line end. Bent it to match the coat hanger and went under the car. I slipped the bent end over the axle and then wrestled the engine end over the cross rails, adding a few unwanted bends in the process and finally into place.

I used blind inserts, 1/4" bolts and clamps to mount the fuel line to the frame. The clamps were generic metal clamps I found at the parts store. I bought the blind inserts and installation tool on sale for about $20. It works very similar to a rivet gun. You drill a hole in the frame, screw on the blind insert to the installation tool, push the insert into the hole and squeeze the handles on the installation tool which compresses the insert in place. Unscrew the tool from the insert and voila, you have a threaded insert!

Insert tool

Blind insert tool

The clamps had rubber sleeves to protect whatever they were clamping. After I put on the first clamp, I noticed that the line was loose in the clamp. I took off the rubber sleeve and replaced it with about 1" of 5/16" (inner diameter) fuel line hose that was slit down the side so I could slip it over the fuel line. Now when I clamped the line down it was tight.

Fuel clamp

Fuel clamp

I slowly bent the line to the frame rail's shape and left it about 1" above the bottom of the rail. At the front of the frame, I ran into a problem where I couldn't fit an electric drill in to drill a hole. I drilled a hole through the frame from the outside a put in a 3" bolt to hold the clamp.

At the motor mounts, there was a problem where the fuel line went over and between several exposed bolt threads. I slipped 5/16" fuel line over the line to protect it. I added a generic inline clear plastic fuel filter on the inlet side of the fuel pump to clean up any crud which is probably still sitting in the 47 year old fuel tank. I got the clear plastic filter so I can see what gets trapped inside. I connected the filter to the fuel pump with fuel hose and left extra in the bend so that when the engine moves, the hose will take up the slack. Since the front of the car is not together, I won't clamp the filter down until everything is back together (just have to remember to do it!).

Fuel filter

Fuel filter

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Copyright April 2011 Eugene Blanchard