Fuel Line hookup

[BelvedereII]

I've run a new 3/8" fuel line in my '67 B-body, and used the original 5/16" line as a return line. A new Wix filter near the carb has a 1/4" barb for the return line, easily completing the loop. However, by now I've got well over 1 foot of rubber line connecting everything. There are of course 2 pieces at the tank, one for each barb there. There's a short piece in the original 5/16" line where I had originally cut into it (at rail under rear seat) to re-connect there, plus rubber 3/8" hoses to connect the fuel pump in the 3/8" steel line. In the engine compartment I ran the steel 3/8" up the firewall on the pass side, turning toward the carb a few inches from the firewall. Rubber line then goes to a pressure regulator, then to the filter and on to the carb. There's a rubber piece connecting the return barb from the filter to the original steel line, and all this needs cleaned up.

I'm going to remove the Cagle regulator since the pump is an Edelbrock with internal regulator and hasn't shown over 6psi. How would you recommend I plumb under the hood, braided hose or more steel line, what kind of fittings, etc.? The carb is a Thermoquad.

BII

[rumblefish360]

I'd use as much steel line as I could.

[dwc43]

And you might try using fittings and a flaring tool to eliminate some of those connections along with compression fittings too.

[pishta]

Thermoquad question regarding 3/8 inch fuel lines. The TQ inlet and bowl filler tubes are dinky. What improvement does 3/8 fuel line to the carb offer? The 3310 Holley, for instance, has 2 bowl fill points, the TQ only has one. When I hear guys running out of gas in the Holley or see "pro-bowls" (massive Holley add on fuel bowls) It makes the TQ look vulnerable to fuel starvation. I got 3/8 into my TQ too but I see the single inlet as a choke point. Yo, D-Sizzle, you out there?

[dwc43]

The only thing that 3/8 line will do is keep the volume at the inlet higher and drop the pressure a bit too. The TQ is designed for the smaller line and that's all it needs. Only stock carb with 3/8 line was the Hemi with dual carbs and six pack carbs. Unless you have an all out race car with high pressure high flow pumps you don't need the larger line. We used the smaller line with the Tq on all our race cars and had no fuel problems with them what so ever.

[BelvedereII]

That's probably pretty much true about the skinny lines. I don't know what "factory policy" was supposed to be, but understand 440s were set up with 5/16" and if remembering correctly, the 6-barrel '69 1/2 RR of Rick Ehrenberg was found to have 5/16" originally.

My first Mopar car was a '67 Barracuda that starved its 360 at the 1/4 mile, and I found the original filter was crushed and clogged. I just removed the filter and kept on going with an open line at the tank. Probably not the best policy, but it ran fine. This Belvedere's filter was just clogged, but I figured as long as I was taking things apart I might as well upgrade---that also let me learn how to bend tubing and set up a fuel line, plus gave me a return line as I've had problems with hot days and occasional stumbles off the line.

Thanks, DWC, I hadn't considered hard lines at the pump, but as long as I've got the flaring tools and the pump's bolted in solid it should work great!

[dwc43]

Welcome,anytime. Yeah, anytime you can do away with rubber lines it's a good idea to do so. Even more important if it's on a race car. Safety issue and all.

[rumblefish360]

Originally Posted by pishta

Thermoquad question regarding 3/8 inch fuel lines. The TQ inlet and bowl filler tubes are dinky. What improvement does 3/8 fuel line to the carb offer? The 3310 Holley, for instance, has 2 bowl fill points, the TQ only has one. When I hear guys running out of gas in the Holley or see "pro-bowls" (massive Holley add on fuel bowls) It makes the TQ look vulnerable to fuel starvation. I got 3/8 into my TQ too but I see the single inlet as a choke point. Yo, D-Sizzle, you out there?

The inner fuel path ways in the T-Q car can be enlarged. Pop off/out the aluminum end plugs and reem with a drill. This mod is generally not needed to be done.
Alot also depends on how far you want to get into the carb. The improvments are minor and few, but sometimes that is all it takes.
A very small dremal head can get into small places and the aluminum is as we know, quick to be wittled away.

If the old racer Mr. Rossi, (I forget his first name) can take a 800 cfm 9800 (or 01 ) down to 9.90 without major mods, I think the carb is capable.

[43 purestock]

Guys, dont forget why the rubber is there in the first place!!!! It will let things flex, and not crack a hard line. The best fix is to use short sections of braided steel hose, if you plumb everthing with solid line like one guy said, you could develop cracks. Just something else to consider!!

[BelvedereII]

I don't see where anybody said to plumb EVERYTHING with hard line, and it's pretty obvious that wouldn't work. I wasn't sure about the fuel pump, but it's anchored pretty well right now and will be absolutely solid when I replace the screws with bolts and nuts. Then I'll cut and flare the steel to fit, cutting out those rubber connections.

I'd like to use braided steel hose, and having no experience with it can someone point me to a good website to learn the ropes of using that stuff...again, with fitting types, etc.???

I'd had problems with the car starving for fuel at the top end (this is only 1/8th mile!!) and found the filter severely plugged when I pulled the tank. I ran for a while with an open end to the sending unit before buying a 3/8 sending unit setup, and I'd also had stumbles shortly after the starting line which I attributed to heat problems---hence the return line. No problem was repeated very often, so I figured the sending unit/top end starvation issue was due to a borderline system to begin with. An occasional stumble wasn't a big deal until I started trying to accumulate points at the track. The finals are generally pretty close, so one stumble is one too many!!

BII

[dwc43]

Originally Posted by BelvedereII

I don't see where anybody said to plumb EVERYTHING with hard line, and it's pretty obvious that wouldn't work. I wasn't sure about the fuel pump, but it's anchored pretty well right now and will be absolutely solid when I replace the screws with bolts and nuts. Then I'll cut and flare the steel to fit, cutting out those rubber connections.

I'd like to use braided steel hose, and having no experience with it can someone point me to a good website to learn the ropes of using that stuff...again, with fitting types, etc.???

Yeah, it's impossible to use 100% solid line in a system to begin with anyways. Only place you need a flex line is from the engine mounted pump to the line on the frame and the cell or tank to the line on the frame. If you use electric pumps you only need a flax line from the frame to the steel line mounted to the carb. NHRA and most race tracks only allow 1 ft of rubber or flex line to begin with too.

Check out stock car products and speedway motors for braided line. It's not hard to use at all. We use it on all of our race cars. You just take the line and wrap tape around it and cut it with a hack saw or cut off wheel. Slide the colar down the line and push the fitting into the line and then tighten the colar onto the fitting. Its' a compression fit. And then you need the correct AN fittings for the carb and pumps and such. Will be An on one side and reg. thread on the other side.