Fuel injection conduit

[FastWoman]

Hi all,

I'm going to be replacing my 78's injectors and connectors before too long. I have all the parts in. As I contemplate this job, I see how I can clean up almost all of the exposed wiring ontop of the engine by creating a wiring conduit for the injectors and some of the sensor wires. I envision fabricating it out of soldered copper piping (painted), with T-joints where each injector wire comes off. I can heat shrink between a nipple on each T and the barb on the corresponding connector. The conduit would be bracketed just beneath and to the right of the fuel rail (between the rail and the valve cover) and would be integral with the fuel rail system. A harness would exit between the #3 and #4, beneath the fuel rail, and would terminate in a large Molex (?) connector, where it would plug into the existing harness (which would be clamped to the left side of the engine, per stock. The idea of the connector is that the fuel rail and electricals could be disconnected, unplugged, and removed as one unit. Anyway, that's the plan so far.

Has anyone done anything like this? If so, what solution did you come to? Do you have any pics?

Any suggestions as to a better connector to use? Maybe one that's weather proof?

Thanks!

Sarah

[Curtis240Z]

The only downside to your design in my opinion is that copper is very heat conductive and I would want the wires to be away from heat as much as possible. On my aftermarket setup I used flexible plastic wire loom. You can see it in my Photo Gallery.

[Walter Moore]

I have used these connectors in the past for industrial connections:

http://www.newark.com/jsp/level5/module.jsp?moduleId=en_US/8173.xml

There is a version of the back-shell that is a heat-shrink and is waterproof.

(Also nearly impossible to remove, so be careful.)

They might be overkill for a car, but I personally think they are way more durable than the typical Molex connector.

[TomoHawk]

Why not a plastic box tube like newer cars use? I'm not too keen on Molex connectors, because they get loose after you plug & unplug a few times (like r/c car batteries) so I would go wit the blade connectors, like you've on the taillights.

[kenz240z]

Please don't interpret my response as a buzzkill, I simply am playing devil's advocate. While the idea of placing the wiring in a conduit would look neat and make for a clean install, it would be a pain if the wiring inside needed to be repaired... Tape & wire loom would be a lot easier to open up if repairs are ever needed. And any additional connector is also an additional potential point of failure. Moisture, hot/cold, etc... could potentially cause a break in the path.

[TomoHawk]

IMO, it just wouldn't look right. Properly wrapped and routed, the few wires that are there shouldn't be unsightly. The vacuum hoses and fuel tubes are more significant than the injector and sensor wires.

Edited December 4, 2009 by TomoHawk

[FastWoman]

Interesting thoughts and perspectives! Thanks!

The heat conductivity issue is something I hadn't considered. Fortunately I have a 1000 ft spool of some nice mil spec wire with Teflon insulation. If I keep the pigtails from the injector connectors short, and patch directly into the high temp wire, I won't have any vinyl-to-copper contact. That should work, I think.

I had thought about the wire loom material; however, I just don't like the stuff. I had it all over my Mustang, and I don't think it worked all that well. I eventually replaced a lot of it with colored electrical tape wrappings, which I think looked much better. Part of the reason I want to do this is that I think there is a beauty to the intake and fuel rail systems. (I know, I'm weird that way.) My objective is to camouflage the wiring in with the tubing and perhaps even to accentuate that tubing look. Wire loom material just wouldn't do the job, as it wouldn't look like tubing.

Walter, I had thought about the style of connectors you referenced, but would the connections be heavy enough? It would certainly be the neatest sort of connector to use.

Tomo, a box tube is worth considering, but where would I find one?

I admit I haven't had the same bad luck with Molex connectors. I find them more reliable than the spade style. In fact I have a bunch of gel pack batteries for my photographic work that I've wired through 2-conductor Molex connectors. They're rugged and stand up to a surprising amount of abuse.

Kenny, I hear your concerns, particularly with the connector. I had thought about (and am still considering) going connector-less -- nothing but solder/shrink joints between the injector connector and the main harness.

I appreciate your input, guys!

[TomoHawk]

For a plastic box conduit, you'd probably have to either build it yourself (from DIY store plastic parts?) or borrow one from another car... I once made something similar using carbon tube that was heated & pressed to form an oval shape. How about an aluminum tube ( polished, of course?) When I see polished copper in a car, it makes me think of those old Builcks & Oldsmobiles with the wooden-spoke wheels...

As for the connector, that's something you'd need when you plan on disconnecting things periodically. I don't think you'll be pulling the engine on the weekends, so leaving the wiring as-is sounds best to me, IMO. As long as it's just the right lengths, routed in nice straight lines (spectators like straight lines on the engine) and wrapped well.

thxZ

Edited December 4, 2009 by TomoHawk

[FastWoman]

Hi Tomo,

No, not BARE copper! Ick! No, I'd be painting it with black epoxy. I've fabricated a couple of other pipes this way, and they look quite OK.

I like your idea of polished aluminum. The only problem is that it's harder to fabricate (e.g. attaching mounting brackets). I'll be thinking about that one.

I had yet another idea that I think has promise and would look pretty cool. Maybe I can use some small dia tubing (1/4" ID?) to run individual lines to the injectors. Then I could bend them neatly at right angles, bundle them neatly together, and bracket them. The end of each tube would end with a 90 deg turn and a length of heat shrink tubing shrunk onto the end, extending to the connector. I could do this with painted copper tubing, with brackets soldered on, and with the bundle soldered together for strength. I might also be able to do it with polished stainless steel brake line. I'd have to figure out the bracketing, but that might not be too hard. (I wish I had the capability to weld. Soldering is something I do very well.)

I know I'm sounding pathologically O/C about this thing, but to me, this is the prettiest part of the engine, and I'd like to make it even prettier.

[TomoHawk]

That one might work!

[Zedyone_kenobi]

IF you can solder, then you can braze. And a brazed joint is Plenty strong

[FastWoman]

Brazing... Hmmmm...

Is that something I could do with SS and a propane torch? I've never brazed anything (unless you consider soldering a form of brazing). What sort of filler alloy could I use?