[roroyal]

So, I contacted Martin last week. I sent him the readings. He offered to send the injectors to him so he could retest them on his testbench. He did that on Friday. An injector would be taken apart and cleaned. Now the injectors are on their way back to me. I hope they will arrive on Monday. In Germany are already again, stop still on the post. My opinion about BBI: top team, very competent, absolutely recommendable. Martin is top!

 

[roroyal]

Now I had this weekend. I've been looking at the injector wells and the xtube wells.
On cylinder 1,2,5,6 the holes for the xtubes are broken out on the front side just before the injector. More precisely where the cross hole for the return flow goes along. At cylinder 3,4 they are still completely round.
Has any of you ever seen this before? Is that from the production of the cylinder head or do I have a problem there?
Figure1, end bore xtube cyl1 cross bore return
Figure 2, end bore xtube cyl3 cross bore return
Figure 3, from above output xtube to injector 1
Figure 4, from above output xtube to injector 3

 

[rghavana]

Never really had to pay attention to that area, but hundreds of Cummins heads I have rebuilt never seen any issue with connector tube area, to me looks like machining of casting.:confused013:
As long as connector tube is in proper contact with injector, installed correctly, should get proper seal.

If your real curious and have time try and contact Cummins by location see what they say :wink2:
https://cumminseurope.com/locations

 

[nosympathy]

I don't see how it would matter since that part that looks like rough casting doesn't play any roles in sealing.

 

[roroyal]

Okay. Thanks for answering. I was afraid that those missing pieces of metal were hanging somewhere in the return duct. I removed the cascade overflow valve from the back of the head. Luckily, I couldn't find a blockage. Check the valve right away. The valve works.
So everything is fine so far.

 

[Grogg]

I have to say this is one of the more measured and data-driven threads I've seen as of late on this forum! Thanks for continuing to follow up with results and pictures. :thumbsup:

 

[roroyal]

Grogg Yeah man, thanks for that. Martin took apart, cleaned and adjusted an injector. Tuesday I put the injectors back in. Xtubes 40lbft. Everything kept extremely clean and blown out several times with compressed air. Everything double-checked. 4 hours I took my time. Then I started and warmed up in highidle. Sounds much better than before and also no more unpleasant smell. Put it out and let it cool down for 2 hours. Fuel lines and rail removed. Xtube nuts re-tightened with 40lbft. At #1 and #3 even 1/8 turn was still possible. Everything reassembled and test driven. RP fluctuation at idle is now 500psi.
But it feels much better already. Shifting on the 48re is smoother. Better balanced
I will flash Smarty sw3 back again tomorrow (I had put it back in stock) and pull a datalog.
Now to my "noise"
It's gotten a lot better. But unfortunately still perceptible. But now #4 is "loudest"
I'll leave it at that for now, though. If I am up for it in the near future, I could try the "cp3 timing" ??
But with this ......:stirpot:. ?..
First of all, thanks to all of you!! :worthy:
Really nice here

 

[rghavana]

Good to here, I would double check valve lash when possible:wink2:

 

[nosympathy]

BTW the updated spec for the crossover tubes is 44 ft-lbs.

Also hopefully you at least checked the exhaust valve lash when you reassembled the rockers.

 

[roroyal]

Oh yes :spank: I checked the valve clearance after installation. Then I ran it twice by hand. Valve clearance checked again. Let it warm up, let it cool down and checked again :nerd:
Since I have completely renewed all pushrods and rocker arm assembly, should I check the valve clearance again after 1000mile? It would not be bad!

 

[roroyal]

I thought the 44ft-lbs was the torque for reassembling used xtubes. Well, these are new. In my manual from 2006 it still says 37ftlbs. Then I heard something about 42ftlbs for new assembly. Can I really use the 44ftlbs without fear of damage to the injector or the xtube? Because this connection should be as tight as possible. You'd recommend the 44 already?!
I had secretly assumed that the "damage/ washout, which could also come from the manufacturing process" in the channel of the xtubes comes from a high pressure leak between the xtube and injectors. If fuel with 23000psi leaks out (the pressure will not be that high, it will be reduced very fast) and meets cast iron it could remove material? At my Injectors return Fuel Test the values in idle were top with 80ml. Only with FCA removed, i.e. at 23000psi the return fuel value climbed to 450ml in 15sec.
So, 44ftlbs are ok to follow? Engine completely cold or still lukewarm? I did not find any exact data. Up to now always with a cold engine.
But in the manual at the injectors return fuel test: measure, if up to 240ml then tighten xtube nuts and measure again. So in warm condition?
What's your experience. I don't have any yet.

 

[steelhead1]

Hope that was air from a compressor with a HEPA filter on the output to remove particles down to 0.3µ micron, 90% at 5µ.
Straight air compressor is as dirty or worse than the shop floor or gravel road

 

[nosympathy]

I just did BBI injectors couple weeks ago, all brand new crossover tubes, torqued injectors to 44 in-lbs then backed off bolts, then crossover tubes to 11 ft-lbs, then injectors to 89 in-lbs, then crossover tubes to 44 ft-lbs.

https://www.industrialinjection.com/media/downloadable/03-07-injectors.pdf

 

[roroyal]

My compressor is not a medical compressor with hepa filter, but there is a complete cleaning system installed for the paint shop. With air dryer, oil separator and highflow fine filter. How much ym this one has I can not say. But in this direction I am not worried. Steelhead, can you verify 44ftlbs On the xtubes for re-Tightening hot or cold engine?
Check my post-42 again. Could that be from a high-pressure leak?
Nosympathy, thanks for your industrial document. Then 44 is good to go. I want to double-check it anyway.

 

[rghavana]

If threads were clean no rust, I would not exceed 40 ft /lbs, thats + 10 % of Dodge value, +20% of Cummins value.
Cummins ISB spec is
Torque Value: Fuel Connector(Cylinder Head Mounted) 50 N•m [ 34 ft-lb ] :wink2:

 

[roroyal]

Yes I know the 2006 Specs.
But many companies that also sell injectors speak of 42ftlbs.
I think Todd wrote that somewhere around here. The question is just when you're trying to follow up, for example the return flow test, hot or cold. I think this makes a big difference. If I tightened 37ftlbs on a cold engine like in the manual and then tighten it on a warm engine like in the return flow test with 37ftlbs I will always be able to turn the nut with 37ftlbs.
If you would then check on the cold engine again, I think you could measure something between 40, 42, or more.
Am I completely wrong or...
How about the 6.7? Same xtubes? How much torque?
Didn't dodge/cummins even officially increase torque?

 

[roroyal]

Oh, holy Time. Tomorrow workshoptime. U-joints on frontaxle outside. They're only wobbly wobbly Loose.
Good Night at all.

 

[steelhead1]

Would not sweat the difference between 37lbs ft and 44lbs ft with new hand picked die besten Jungs BBI injector German high strength steel and the best HD Bosch 6.7 tubes.

Hell, English subs in WWII hit crush depth long before the German Uboats. It's the steel and construction. Favorite trick of the German U boat commanders, get the British sub in high speed pursuit, then head deep at steep dive angle. Horrible crunch sound on sonar

There's mathematical theoretical limits and then there is "Goddamn, I'm still alive" limits