You'll be fine. I did the same as you when I installed my new injectors. After 2 weeks, I decided I wanted to hot torque them and got about 1/4 turn on each injector to re-achieve 120 in/lbs torque.

 

Retorques or, torque checks, are pretty much always required on any fastener. 50 does sound a little low though doesn't it? Assuming people want to use a torque wrench in the first place, lots of people don't seem to get the retorque part. Oops! Heat cycles, vibration, parts shifting around, whatever, it is very common and expected for parts to "loosen up" and must be planned for. After a few torque checks, after several hours/heat cycles etc, then the fastener will stabilize, and not move anymore.

 

‘It quieted the engine down’ is the most subjective, unscientific, non-repeatable, non-quantitative metric ever used to justify a mod.

Human nature dictates people will get the results they are looking for.

I have installed several dozen sets of injectors. (2) in the last month. I have never re-torqued an injector. The last truck had 380k miles on a set of injectors that never got a re-torque.

 

That gives me comfort. If my digital torque wrench is nearly as accurate as your calibrated wrist, and my Loctite holds, I should be good. Which would be great, because I really don't want to go back in there.
I will say that with Clay's stainless cups, which are considerably thicker, the engine sounded, uh, "different". Quieter, I would say. But I do agree, that can be highly subjective.

 

I actually have to counter this. When I had the "Stinky" problems, I knew I needed a retorque just by the sound of the engine. Even the instructions from the first post describes knocking as a symptom of loose injector bolts. I've had a document that looks like that for years, but maybe you can help me find the excerpt from above: https://drive.google.com/file/d/0B-n...ew?usp=sharing.

If you drive a grocery-gitter, the engine goes through so many acoustic gyrations as it warms up, that you might not even know what the engine is supposed to sound like. If you rock on to Mark Knopfler guitar solos while driving, the only engine noise you'll hear is drone. If you commute an hour each way on the highway like I used to (with the radio off), you know every tick and tock the engine makes.

A fellow member brought his rig to my house so we could do some glowplug maintenance. While we were in there, we tightened up the injector bolts - since I've always been obsessed with those. My friend had to drive home in excess of an hour away, over a mountain pass. He called back and mentioned how surprised he was that the engine was so much quieter - he didn't expect that.

I agree that thread locker makes a thread lube - if you buy the slow-set type. I have the advantage of having a warm-up tune (and an exhaust backpressure valve) to warm the engine up to full very fast. I torque, heat, and retorque with the valve covers off - all well withing the thread locker cure time.

 

just looking at what is being tighten I would say it has nothing to do with the bolt.

Seems to me that what is being compressed and adding the resistance which results in the torque reading is the injector cup deflection and the cup to washer to injector tip fitment.

the “relaxation” Ford mentions would be the cup and washer going through the process of plastic deformation and not a loosening of the bolt.

the cup-washer-tip assembly is acting like a spring washer that keeps the clamping bolts from loosening up.

if you want to retorque your bolts you will need to remove them and clean both threaded mating surfaces to remove the hardened sealant as it will affect torque value

 

Not that I have time or the desire to do it, but, it would be very interesting to set a datum and measure that distance (to a known repeatable point, say the solenoid) after initial assembly and then again after a few heat/compression cycles. I too, think it the copper washer collapsing.

 

I simple test too would be having a .0001 indicator on the injector while torquing or retorquing.
That would provide some real numbers.
Surprised no thought of that before.
Great idea.
Note: It would be much harder to just measure a before and after height, but anything could be done.
Temperature related expansion would be difficult to control.
Bob

 

I have driven my truck 350k miles, put 120k miles on my Excursion and have easily driven well over (100) 7.3’s.

I would argue that I have a great ear for what this engine can sound like. That said, there are (6) in my driveway right now and they all sound different. Quantifying the way they sound is futile - everyone would describe something different.

There are a few trendy mods that have no scientific data to support them, but they sure make people feel good! (Just read the reviews/posts) No harm in most of them, but I just refuse to be a lemming.

 

I don't necessarily disagree, but I do have two observations:

1.) The bottom of the cup should be bottomed out against the top of the cylinder head; that is what stops it during the insertion process. Of course there still may be a very slight gap.

2.) I don't think of the copper washer so much as a "crush" or a "spring" washer, as some have described it. Copper expands with heat at a significantly higher rate than iron and steel. I think that is why they used copper in that location. Higher temperature makes it seal better, similar to copper exhaust gaskets. Of course it is softer, too. So there is maybe an initial crush of the washer during assembly, then further deformation of the washer due to expansion during temperature cycles. It could also be that the initial expansion of the copper pushes the injector up slightly, then it shrinks back, and that's why the hot retorque results in further movement of the bolts. However, I think that every time the copper reheats, it's going to seal again. Just a hunch though, really. Copper was selected for that location for a reason.

 

I found a pdf of the same book here: https://www.powerstrokediesel.com/do...Table_Book.pdf

Todd

 

I dunno....torque or don't torque. If this causes owners to get under their valve covers other than for changing glow plugs, good deal. I don't see how tightening up tolerances can hurt anything, so I doubt there is a placebo effect with this maintenance. I don't really consider it a "mod" anymore than changing oil.

Whatever makes us feel good regarding our trucks, then do it. It's why we own them to begin with.

 

Wow this thread is messing me up!! lol My initial plan when doing the injector O-rings was to use denatured alcohol to clean all threads And have them as dry as possible. Based on what I read in the first post my plan doesn’t seem as right as I thought...

 

I think this post has been a great point of discussion and brought a lot of suspicions and ideas about injector torque specifications and methods to the table.

Even after reading this thread and all of the posts over the years about cold torque, hot torque, loctite, cleaning methods, etc I can tell you that if/when I need to install new Alliant AC code 160/0 injectors I will clean the threads of the hold down bolt holes. I will then use new bolts from Riffraff and loctite 243 and cold torque the bolts to 120-130 in/lbs. I will then ensure the loctite has plenty of time to cure and button everything up. I will not remove the valve covers after a certain amount of mileage or heat cycles on the engine to check the torque of the bolts. I know that my OEM injectors are still running strong and could last another 100 or 200 thousand miles. I see no reason why to mess with the torque specification upon installation of the 160/0 if/when I ever install them. I don't know how long I will own this truck, but I can tell you that if the 160/0 get me another 250,000 miles then I would be glad not to have to remove the valve covers ever again...

The way I see it is that the OEM 255,000 mile injectors are still running strong and I have not checked or hot torqued the bolts in anyway. The loctite 243 on the new Alliant AC 160/0 will act as a lubricant as spelled out by the documentation posted by SkySkiJason and ztodd377. This method (in my mind) will not only satisfy the Ford specification, but will also satisfy the OCD specification.

This is just my chosen path to success based on what I have read, seen or heard in person and what I know about my 255,000 OEM AD injectors that are running strong.

We bought this truck to haul the 5th wheel camper around the country, not to work on it and worry about it all the time. I do a "modfest" every winter and each winter since buying the truck 6.5 years ago the list has gotten shorter and shorter. This year was silly things like a kill switch, on-board battery charger, etc... We believe that the truck is fully capable of taking us anywhere we desire in this great nation and we are grateful for the FTE, the 7.3L diesel and a nation that allows us to be who we want and aspire to be.

 

Set it and forget it?!?!?!? Insanity! You gotta tinker with everything frequently or it'll blow the F up! Haven't you learned anything in your time here?!?

I think your plan makes sense for covering the Ford and OCD specs assuming the loctite has a similar friction to oil which I don't know, I would investigate that. Or just do the hot torque thing which should also make it so you never have to go back in there. I seriously doubt that the bolts back out over time so the loctite might be pointless. It makes a lot more sense that the loosening over time is because of things settling, if the bolts were backing out they should keep backing out and become totally loose....in my theory. Or maybe they do and that's what leads to o-ring failures and people just don't bother checking the torque since they're removing the injectors to do a re-seal.

Between cold and hot re-torque I got about another 1/4 turn on mine. Normally I would never add 1/4 turn to the factory torque setting of something, but so many people have done the hot torque and I could't find any examples of failures so I went for it.