Nice silver soldering. You should be OK but a bit more capillary area would have been safer.
Your napkin sketch wouldn't have worked because the force on the damper is asymmetric.
Viton is compatible with silicone grease, some butyl/neoprene rubbers don't much like it.

 

Well something is not right then. The warning against silicone grease, but the requirement for grease during installation came straight off the vendor engineering drawings.

 

RE: O-ring installation lube. I have always used vaseline when installing injectors, and did so both times I installed the injectors in this car - it works great. I use a Q-tip to put a very light coating on the outside of the O-rings before installation - and they slip right in!

Now, Here's a story and some new pics!

This morning, as I was driving to work, I began thinking that even though silver solder is very strong, I would have real problems if, for some reason, the solder suddenly failed and the bolt blew out of the rail dumping a stream of 70 psi fuel directly onto a very hot cylinder head and splattering all over the engine compartment! Ummmm, yeah... Probably not very pleasant results huh?

Tonight when I got brave and blocked off the first of two damper "cups" on the actual fuel rail that will go back on my car, I got to thinking again about devising a "keeper" to add a solid mechanical "safety-stop" to the capped off damper cup. Steve was undoubtedly correct when he surmised my dentist waiting room sketch would not work very well because it didn't apply even pressure. As I pondered a new design for a "clip type" of keeper, I looked at the pile of old Ebay injectors and clips from my research rail still setting on my workbench and BOOM! it hit me. I have what I needed right in front of me!!!

All I needed to do is get a ball-peen hammer and a punch then bend the spring steel "tangs" that used to slide into the side of an injector down just a little bit to apply pressure against the soldered "cap" when the clip was in position - and I had my solution...

There's NO way that bolt's blowing out now! AND the solder is solidly backed up with proven mechanical advantage!

How 'bout that guys?

Now all I have to do is solder up the other rail's damper cup, modify another clip and it's "reassembly time!"

 

... umm all very neat but ...

A mechanical backup isn't going to help you if a small gap develops.

How about just pinching the cup shut and silver soldering the seam?

Or cutting the cup off and patching the hole? If you have some slightly larger tubing than the rail and cut say 1/4 of it away, then it acts like a very wide circlip. Rotate the patch pipe/circlip over the hole and silver solder. Then the "circlip" is your mechanical strength and the silver solder is the sealant.

Then again, you could just cut the fuel rail slide the cut pieces into a proper sized pipe and have the whole works tig welded back together. Of course you have to jig it up properly to maintain alignment.

 

Petroleum grease is recommended for fuel based installations presumably because they worry about excess silicone grease getting downstream of the installation and damaging something else.
Maxwdg, like Plums I don't like your solution, beautifully crafted as it is. You've got a line contact between your bolt head and the tube. Think about a plumbing fitting where the pipe fits some way into the joint socket and the whole mating surface is filled with solder. What you want is a brass plug extending into the socket and silver soldered in place. It would take 5 minutes to make on a lathe - I'd make you a set but I'm not going to be around much for the next few weeks.

 

.. ok ...

lathe a plug for interference fit, preferably knurled at bottom but relieved at top for solder flow, put rail in oven because we don't want to melt such a valuable beast, put plug in freezer ... do the usual drill of mating them quickly ... then silver solder

.. or ...

as above, but after assembly drill through cup and plug and drive a retaining pin through the works and peen over the ends before the soldering step to avoid excess shock that ought to hold it

 

Why not just cut the cups of and tig weld it, easy, fast and secure (although I would still go for replacing the fuel dampers, but I’ll get my coat ;-))

 

Whoa! I'm feeling beat up a bit here! I suppose I opened myself up for it - and I DID ask for opinions - but Damn, I'm doing the best I can with the tools I have. I don't have a lathe - I wish I did. I have friends and a father in law that do, but they are as busy as me and my father in law lives 350 miles away. I guess it's the opinion of the masses here I'm "backyarding" it a little too much.

Plums and Avos: There's a reason I don't remove the cup or bend the crap out of it....I'm trying to seal the "cup" in a way that
they will (hopefully) never again leak by silver soldering - but I want to maintain the integrity of the rail and cups - so that if it becomes apparent that the car doesn't run right without the dampers, I can buy new ones and take my chances on getting a good seal with new O-rings.

AVOS, I'm not adverse to trying a new set of dampers and new O-rings - but since the new O-ring didn't work the first time I tried that, and I had to re-do all the work of taking the engine apart again - I thought I'd try eliminating them first...

Plums, Like your idea, my first thought was to get rid of the cup and tig weld the hole shut. But as I said above, I'd like to have the option of back tracking. Jaguar wont sell the dampers alone and wants nearly a thousand dollars for a new set of rails - so the LAST thing I want to do is massacre my rails, by cutting off the cups or by stretching out the metal of the cups by plugging them with an interference fit plug.

Steve: Had I a lathe, I already would have machined a tight fitting plug with a top hat that had an inside groove in it on the underside of the top hat for the shoulders of the cup to fit into - the plug would also come back down on the outside of the shoulders a couple of millimeters in order to provide a nice deep well for the silver solder to really wrap around. And I'd solder it by turning the rail/cup assembly upside down. That would seal it for sure - AND be removable, If I wanted it to take it off.

I thought I had something good going on - but I may need to rethink this entire deal.

 

Not at all. Just trying to help by brainstorming.

My personal favourite so far is the plug+pin. A plus would be the above noted remote mount damper. That meets the goal of never going back in. But, drilling for the pin is going to change the cup permanently.

To backyard that one maybe some round bar stock of suitable size chucked in a drill held against emery paper or a file. The "stock" can be anything round, metal and of suitable size.

Of course there is the option of reinstalling as stock and crossing the fingers. On the one in the car, you don't know if the shop lubed the o-ring or not. It might be the entire problem.

edit: given the dimensions, your father-in-law could chuck in a piece of brass, lathe it, and mail it to you.

 

We're with you on this - no-one wants to see this s/c coming off again !!
A brass plug wants to be an easy fit for capillarity so your father-in-law could do it blind.
Like you I favour a reversible process with no damage to your rail.
Are there just two damper cups, one per rail ? If you're stuck give me the ID and I'l machine you up a couple of plugs.

 

Don't forget to wrap in bacon greased paper for corrosion protection during shipping!

 

Of course not!
If he'd only used your much vaunted Plums Cobra fuel rail damper snake oil assembly agent this wouldn't have happened.

 

Thanks guys, your critiques and concerns pushed me to make a call to Oklahoma City last night.

Dad-In-Law is going to make a couple of SS caps for the two damper cups on his lathe for me. I sent him the dimensions. We're going to go with the style I described above - where the caps are only a millimeter or so larger in diameter than the shoulders on the cups. With about 2-3mm overhang so that a nice full pool of silver-solder with lots of surface area will grip that cap tightly and provide a certain seal - without ruining the cup for the potential of future use.

Plums, I have found a source for an outboard HighPerformance damper that I can plumb into a tee cut into the the center of the flexible hose that connects the two rails - if it becomes apparent that a damper is required for this EFI system.

http://injectorfi.readyhosting.com/p...duct-sheet.pdf

You may be right in the speculation that the injector cleaning guy in Houston, TX didn't use grease when fitting the O-ring on the damper that was leaking - but I kinda doubt it (mostly because, when I got the cleaned injectors and supposedly fixed rail back from him, he included an instruction sheet specifically advising me to use a bit of lube when installing the injectors into the rail and into the engine.)

Hey, point of observation here: I did note that when I was testing the damper for leaks, I pushed the damper up into the cup as far as it would go with my finger and then, when I put the pressure to it, at about 50psi, I noticed an obvious (1-2mm) outward movement of the damper from the cup (eventually caught and prevented from blowing out of the cup by the integral clips). When I turned the pressure off the damper sucked about 1mm. I figured I was observing normal flexing of the O-ring... Perhaps I was seeing too much travel and that was precisely the cause of the leak?

I suppose I could have tightened the clips until there was no movement at all - and checked it like that.... Hmmmm, I hate thinking of things after the fact...!

 

That will work. Good luck!

 

Custom Machined Caps!

Received a little package from Oklahoma City yesterday - Guess what? It contained a couple of stainless steel caps that just happened to be exactly the right size to put a stopper on two fuel pulsation damper cups...

See the pics for the result: Pressure testing tomorrow night.

Cheers!

 

Hmmm ... nice fit ... I'd almost think they were custom made

 

To finally put an end to this story, I am happy to report that after a 24 hour pressure check of the rail at 125 psi and the final reassembly of my engine, my XKR started right up and ran very fine. There was no noticeable increase of injector noise at idle or at engine speeds of up to 3000 rpm… In the garage that is!

The morning after I got the engine restarted and pronounced it ready for a test drive; Kansas City received our first solid snow! My shop is in the basement of my home and the nearly twenty-degree incline to the shop entrance makes for an impossible exit while snow is on the ground. So I'll have to wait for a while to give her the full road-test.

But who wants to drive their pride and joy in this kind of weather anyhow - agree?

Also included: a few photos which I annotated - to give
those interested an idea just what was under all that induction
hardware on top of the supercharged V8s, and to illustrate why all
that hardware has to come off the engine before the fuel injectors
could be accessed.

Thanks for everyone's help with this project!

 

Great stuff - a battle well fought.
Let's hope you won't be seeing any of the stuff in your photos in 2013.
I bet you've got the World record for s/c removal now.
I'll add the pics to your s/c removal sticky.

 

Temperature outside hit 52 degrees today!

I got the Jag out of its winter prison last night and put 50 miles on her...

Whew Weeee!!!! Runs Great! I cant hear any injector noise from under the bonnet either. The only thing I hear is the S/C screaming!

Fuel trims all look perfect.

And no fuel smells.

Yessssss!

 

Now then, Barry, you know what happened last time you said everything was OK.
But, for MaxGawd's sake, you do deserve a break.