Many of them going 100’s of 1000’s of Miles and not causing any trouble.

 

Maybe the factory install is done similarly to the shop manual requirement using the same or like tool.


OTC 6067 Injector Tool

 

Just for the heck of it, I did a few rough calculations, using the temperature coefficients of steel (for the injectors) and copper (for the washer). Assuming a length of 6 inches from the bottom of the cup to the surface where the injector meets the hold down clamp, and assuming a washer thickness of 0.06".

For a temperature rise of 120F (assuming 190F operating temperature), the injector would expand 3.6 mils (0.0036") in length. The copper would add another 0.048 mils, for a total of 3.65 mils.

Meanwhile, assuming a thread pitch of 0.4mm for the bolt, a quarter turn would account for about 4 mils, but you have to divide that in half, because the injector resides in the middle of a see-saw. So every quarter turn of the lower hold-down bolt moves the injector about two thousandths of an inch.

I'm only throwing this out there to give perspective to the tiny amounts of movement we're talking about. If you hot torque and gain another turn, you've only moved the injector down two thousandths of an inch.

BUT, these two things should be working against each other. If you gain a quarter turn during a hot torque, there has to be something else going on, because the expansion of the injector and the washer from the heat should have made everything tighter.

Everyone fee free to check my math. In fact, please do!

 

Regardless of the ideas and theories provided here, we cannot discount the millions of millions of miles that 7.3L engines have accumulated over the years without a hot torque check. That is not to say there isn't some benefit to to a hot torque, but it more than likely is completely unnecessary unless there are issues present that may be related.

What does Alliant say about injector torque? From the documents pictured and linked above, we know what Ford says.

There is a thought that makes sense...

 

That may very well be the case. Maybe Ford accounted for the settling when they published the spec. I agree with you that it's hard to argue against the millions of miles put on 7.3L engines with torque values of under 100 in-lbs.

That injector o-rings or cup failures can occur if the torque isn't adequate, although I don't remember what the threshold is off the top of my head.

 

I think that tool is required in E-series because you cannot smack the injector with a rubber mallet like in SD’s.

On that note, I smack a well-lubed injector until it bottoms out (noise changes). I don’t feel like I’m pulling the injectors down with the hold down bolt. Other than what it’s like to tighten a banjo bolt or similar with copper washers.

I have new and old copper washers here. I guess we could measure them and even install an injector and remeasure. To determine how much the washer has to do with it.

 

In my case, if just tightening them down to spec worked, that would have been the end of my involvement. I played Whack-A-Mole until I had a VC pop down to 5 minutes per side in a hotel parking lot, growing weary of those damn things coming loose enough to make engine knock videos. Hot-torquing them with thread locker ended the carnival game, and I finally got my prize. I've easily done about 50 rounds of torquing - I have a 2-quart jug half full of injector O-rings and Clay can confirm I spent plenty on injector hold-down bolts. With all that practice on the same two VCs, I can say hot-torquing is a critical step to that sewing machine sound on the highway. Other than that, I won't say there is anything to be gained from hot-torquing unless your injectors won't sit still.

 

The cylinder head also expands in height so it's going to counteract the injector getting longer. The head has more mass than an injector and is a different material, no idea which one will expand more. The injector bolts also expand which will make them looser. That might be enough to explain them being looser when hot instead of tighter.

 

All i know is the reading in that google docs link posted earlier and jasons book is pretty cool, anyone know if the 99.5-2003 book is much different, especially in rreferene to the injector torque.

https://www.powerstrokediesel.com/docs/00_73L_DIT_Coffe_Table_Book.pdf

I should add that page 34 of the pdf, (33 in book) is going to be very useful in my shop toolbox
I remember my 2002 i bought new sounding very similar to what my 03 does now, both in stock form, my wifes 2001 in comparison to my 2003 sounds like a 24v 5.9 cummins compared to a 5.9 common rail, lol

 

This link offers more of the Ford "Coffee Table Books" including the (few page) 1999.5 DIT Engine Update book to the previous one linked twice above.

https://www.forddoctorsdts.com/coffeetablebooks.html/

 

well deserved reps thank you, im having a few of those printed

 

Thanks, I've had the appropriate manuals for my needs saved on my PC for a couple years now, whenever I find something researching, I grab it fast. Maybe these should be saved to the tech folder as a direct PDF if possible instead of a point to link, in case the link changes in the future. I still haven't found a book for 99 and up.

 

Our file/attachment size limit here on the FTE is 10MB...

The best I can do is make a link to the "Coffee Table Books" in the Tech Folder, which I have done. The "1999.5 Update" book link was already there, but I added the others as a single link to the directory.

 

How woukd i add these to google docs? The site in that link is EXTREMELY slow to download? I left my computer at work on downloading them because it was going slow.
i plan to have the 98-99 and the 99.5-up printed and spiral bound together. And the 94-98 separate for my 97

 

I just downloaded both of those in seconds with our 9 MB connection speed. Try now...