Example of some fine Cummins work quality

So what about them overhead cams?

And are you suggesting a bolt will back off the 90 degrees and then also lower then 300????
Confusion aint on our end.

 

What I gathered from that post is you torqued it up to 300 ft-lbs in sequence, then ran it 3 heat cycles? Then re-checked the torque at 300 and then gave it the 90 degree turn on each bolt?

I'm amazed you didn't blow the headgasket out doing that. You had to have been at least 25-30% shy on headbolt clamping force.

 

there is new torque wrenches out that has a setting, where you torque to the ft.lb an it has light that lights up when you reach the degree it calls for after the torque setting. snap-on and mac. has them . even new cars require this way of torque procurer. I have never used them. a guy I know has one an showed it to me.

 

This is a reman engine, not a new one and not one with a new headgasket.

I am going to guess one of two things;

One is that the company that did the reman wasn't cummins.

two is that the engine was just one that was destined to be a problem.

We fleet owners have had number two a few times, I have one sitting right now in the shop for a week after it burned through another set of injectors. That engine is possessed.

 

coming from automotive engine machining
re -the 90 degree value IS a tongue measurement .All of Fords heads and mains are tightened to a torque in foot pounds THEN rotated a set # of degrees of rotation.
Long retired but thats how we did it stating in the late '90s.
It was found to have less variation : this was all done by machine all in the same instant.

 

I'm not seeing less variation when there's no gaurantee of exactly 90 degrees. And torque variances.

That was always a concern of mine when i did gasoline gaskets. Torque differences

 

Torque to spec ,say 50% of stretch required ,then any # of degrees found to give the rest of the 'stretch'
That is why we never ever reused bolts,they are stretched to max strength and do not completely return to original length

 

in mass production the issues could be different then shop work, but that is what we did about 1000 times a shift.

 

I have no clue and Cummins doesn't either, the truck is sitting there with some regional people looking at it. The injectors (2 and 3 and 5 and 6) go bad quickly and they can't come up with a legit reason at all, I rejected their "well the fuel filter hasn't been changed" crap, not only did I have the filters changed, I had the driver save them and send them to me for the last round of filter changes. They were handed over to them when I met them last week.