Injectors without o-rings... do any exist?

So I was looking a bit into how return lines work on other diesel engines of the same era.

On the Detroit 6.5L, the injectors have two metal nipples that a return line hose just slips onto. Some hoses are made that don't even require clamps. All injectors have two nipples, so a cap is placed on the injector(s) at the end the line. Leaks are reportedly pretty rare and easy to fix.

On the Cummins used in Dodge Ram, hard lines are used with banjo bolts. The attachment is at the back of engine and very hard to get to. Leaks are basically unheard of.

And of course the 7.3 uses this rinky-**** system of o-rings and plastic caps that will leak if you look at it funny or forget to sacrifice a chicken before installation.

So my question is: Would a detroit injector fit (and work) in a 7.3 (doubtful), or does anyone make an injector of the Detroit style that will fit in a 7.3?

If I could find such an injector I would gladly install them and never look back.

Chickens are cheap. Just don't forget. ;-)

danda said:

So my question is: Would a detroit injector fit (and work) in a 7.3 (doubtful), or does anyone make an injector of the Detroit style that will fit in a 7.3?

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No and extremely doubtful. The biggest with leaking o rings is that someone tries to get away without replacing all of them on one side at the same time. When they've been on for a while, once you disturb the seal, that o ring will leak. That includes just bumping the return line or cap.

The only upgrade I know of for return lines is billet return rails. They still use o-rings of course

There is also the Brass Caps from Dregs Garage, but they also use the Rubber O Rings.

I have a 82 Datsun Diesel 720 with the Nissan SD-22 engine. Here is a picture of the style they use. This is a Kabota listing but same thing.
I have never had a leaker in the 30 years I drove it.



And these are the Copper Washers for between the Injector and the Rails, and the Aluminum ones for the top.






Goat

I've been thinking about this recently as well. I really hate the plastic return caps and rings. I believe it would be possible to tap and thread a fitting into the return port on the side of the injector or otherwise solder a barb fitting or similar. But the amount of work and aggravation it would require just doesn't make sense to attempt. At least for me. And of course there would be additional complications like needing to reroute the return lines and teeing them together. And that hole won't line up cause it's at the mercy of where the injector stops turning after being torqued.

bumblebeer said:

I believe it would be possible to tap and thread a fitting into the return port on the side of the injector or otherwise solder a barb fitting or similar

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yeah, maybe enlarge the hole a wee bit and tap.

needing to reroute the return lines and teeing them together

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yeah, might be cleanest to have a barbed manifold for each side that all four lines go into.

And that hole won't line up cause it's at the mercy of where the injector stops turning after being torqued

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yeah, not optimal. maybe set the torque a few pounds light, then keep going enough to make it align, I dunno.


Perhaps could be a good little business for someone here.

anybody up for the challenge?

The other designs you mention, are still easily screwed up by the guy working on them. Though the hardline stuff is probably the longest lasting setup, crappy washers that don't squish correctly and bolts don't always stay tight do happen.
On the bosch style gm idi injector, hose quality has been poor the last few years, And finding the one style hose they used is difficult/expensive, and don't get me started on those clamps.
I dont like the idea of the plastic caps and orings and fuel line and clamps either......but, done correctly initially, this set up typically doesn't have problems.

That would be great to tap the return ports and screw in little barbed nip ples for rubber hose to connect each Injector together.
How would you then screw on the cap for the hard Line?

Leaving the Injector not torqued down to the required torque setting, and leaving a bit loose so the hole line up, will cause blow by (from Compression) past the Copper seal and Injector.
This will cause you a big head ache later on trying to remove the Injector.

It`s great coming up with new ideas...back to the drawing board.

There are better return systems on other diesel`s, but what we have, is what we have.

I haven`t had a leaker in a few year`s, but when I do, I pull that side off and replace all 8 O Rings, grease caps and snap back on.
And truck on.


Goat

Old Goat said:

How would you then screw on the cap for the hard Line?

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Well the hard line thread is well above the hole that would be tapped, so I guess I don't see the problem there.

I agree its not good to leave injectors untorqued. It might be better just to route hoses however they end up. wouldn't be so pretty.

Regarding leakers, I recently had two that just would not seal until I finally put an extra o-ring between the hard-line nut and the plastic cap to firmly hold the cap down. goofy.

Old Goat said:

I seem to remember reading, using a copper Oil Pan Drain Plug washer on top of the plastic cap.

Advance this video to 10:50 where he shows how he does it.

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Goat

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I've seen this done before and it looks like it works well, but it also deforms the top of the return cap. I'd be afraid if you have to crack an injector line for any reason that the nut or cap may get shifted and wouldn't seal properly again. Obviously this would happen anyway with old o rings, but a newer set should be able to otherwise withstand a bit of movement no?

I think the most realistic mod, and the one I'm currently running, is to put a flat rubber washer between the bottom of the return cap and the body of the injector where the flats are. Then put another smaller rubber washer between the top of the return cap and the fuel line nut. So that when you tighten the fuel line, it compresses the entire assembly. This seals the top and bottom of the return cap to the injector body that way if the o rings do leak the fuel would still be retained within the cap. Basically a double layered seal. I can try to get some pictures to upload if anyone is interested.

O-rings last a long time. I changed them on my motorhome 4 years ago and still going strong, even in the very cramped and hot van chassis engine bay with turbo.

Dregs Garage brass caps were expensive, and worth it. Not sure he's still in business?

Definitely use viton orings.

while I'm not the biggest fan of this system but if you install them right with properly fitting parts i haven't had any issues in 2 years its as simple as making sure your return lines aren't too long causing them to stress the o ring and making sure you get a nice click when putting them on sometimes i have to use a socket and a rubber mallet