Routing fuel lines when using USCartool Subframe Connectors?

[Dakota]

I am going to need to drill at least one hole in the chassis for the fuel lines.   I'd appreciate hearing some thoughts and experience on this before I actually do it.

I have a 70 Challenger with a 340 4 speed.  I added US Cartool Subframe Connectors (SBCs).   The front end of both SBCs overlapped about half of the rear-facing side of the 1" hole in the crossmember that's used as a pass-thru point for the fuel line(s).   At the time I put in the SBCs, I decided to weld over the entire hole on the rear side.


I'm going to have an AN6 (9/16") braided feed line for an FiTech injection system, a 3/16" return line (a repurposed feed line), and a 1/4" vent line needing to run from the fuel tank area to the engine compartment.   I think I'll need all of a 1" hole and maybe a little more to fit all 3 lines.  Since the original hole was dimpled, I'm a little concerned about losing some structural strength if I simply drill a new hole.


Should I reinforce the area around the new hole?   Drill 2 smaller holes?   Any suggestions and photos of approaches used would be appreciated.


I'll have the same issue on the driver's side with the brake line, but I only have one line to get through so it shouldn't be that big a deal.


Yes, I did leave a path for the emergency brake cable through the driver side SBC.

Thanks!

[Cuda Cody]

In a stock set up when adding subframe connectors, you only need to have a hole for the E-Brake. 

[jimynick]

An AN6 line is 6-16ths" or 3/8" so that might help when calculating the size of hole you'll need. As for structural issues, I wouldn't worry too much, remember the factory hole was that big originally. You should be good. Good luck! 

[GoodysGotaCuda]

Try to only make holes in the subframe where the section view is the largest. Not where it necks down at the back.

I ran my fuel line within the subframe connector. Are you still running a charcoal canister, for the 1/4" line?


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[Dakota]

I plan to add a charcoal canister but don't have one yet.   When I bought the car, there was a vent line running into the engine compartment but it was "sealed" with a piece of duct tape.

[dodj]

In a stock set up when adding subframe connectors, you only need to have a hole for the E-Brake. 

The lines just run down the passenger side and don't cross to the other side, so why do you need a hole? 

[Dakota]

Maybe this screenshot will help explain why I'm scratching my head.   I took a video of the fuel line routing before I started tearing everything apart.   The hole that the fuel line disappears into in the picture no longer exists.  It's partially covered by the subframe connector (SBC) and I welded up what was left open.  I didn't want the SBC to butt right up against the torsion bar socket as I didn't think there would be enough room to weld.

The hole on the other side of the crossmember is still there.   

If there's a different route the fuel line is supposed to take in this area, I'd appreciate being pointed towards a diagram or a picture.   If this screenshot shows the route I should take, then I'll drill the smallest hole I can adjacent to the old one to fit the combination of the new fuel line, return line and vent line.

Thanks.

[Dynamo]

this is my 72 with the frame connectors and it only partially covers the hole. hope this helps

[Dakota]

It seemed like a better choice to remove some of the extra stuff I added instead of putting a new hole into the existing crossmember.   I ended up using a 1" hole saw but fed through the existing hole in the front-facing side of the crossmember.  The remnants of the hole on the other side served as a guide for the drill bit.  I ended up drilling into the end of the subframe connector (SBC) which left a pair of slots in the SBC side.  Used the same hole saw to drill in perpendicular to the previous direction to completely open the hole.  It may be hard to tell from the pictures, but it seemed to work ok.  I still need to get rid of the sharp edges but I think this will work.

Just for laughs, I included a pic of what I pieced together to drill the hole (had to include a swivel because there wasn't enough room for the drill otherwise): drill to a 3/8" socket adapter to a swivel to to 3/8 x 1/4" reducer to a 9mm socket to the hole saw. 

Yes, it would've been SO much easier to make this hole before welding in the SBC. Lesson learned.   Not sure there's going to be another project car to apply this lesson to. 

[gzig5]

I don't know if it is an option for you, but I would tack in a piece of thin wall tube to connect the holes on each side.  Provides a nicely chamfered internal edge and if you fully weld the circumference or use sealer, it will keep any water from getting into the frame.  I think that method just looks cleaner too.