Cummings can supply you with a go no gauge to see if you should reuse the bolt..
Being that when they loose their elasticity and or break...it is not worth the even considering using a old bolt ..unless you like redoing a job
The final torque . is 90 deg from the last given number value with no specific foot lb given.
If that is done, and the stretch is gone ..every time a cylinder fires the head will jump up and off the block creating a gasket leak.
Yes they "say" you can reuse the bolt so technically it can be done...But as for me it is too risky
I remember the old 855 series with 3 heads..kept having bolt problems . The shop would pull the head reuse some of the bolts and a 1000 bucks latter it would be fixed.
after the 3 time I took it home R and R the heads with a real proper clean job, installed new bolts at 8 bucks ea. Never had the problem again. In fact as of a few months ago saw it , asked about it and still trucking ! (I did this like 10 years ago )
So.. were just having coffee and a discussion here..and every one has a opinion and can do what they like

 

you guys that want to reuse cummins head bolts can use any thing you want, even rubber bands, but i for one will not have premature HG failures

 

Ditto Johnh
When one considers that the head would like to leave the block and go to the moon...The clamping force is a big issue

 

The sad thing is, you will never know. If I had a nickel for every time I saw a mechanic keep pulling on a spongy bolt, I could have a couple of head gaskets replaced. I had a brand new set of "super" head bolts that were junk right out of the box, tried to get the MFG. to listen, they said run them, they won't break.

Needless to say, I was pulling the heads and they paid to have another Mfgs. bolts put in.

Unless you watched the Mechanic gauge the bolts, inspect the head for flat, and torque the head down, you have to assume his competency, which we all know varies greatly.

What we do know is the B series head bolts are not torque to yield, and if they fall within the stretch gauge, Cummins has no issues with us using them ( assuming reasonably close to stock pressures.).

If I had reason to worry about using bolts that fell within the use range, I wouldn't buy new head bolts, I would head straight to studs.

As they say, to each his own.

 

Hi,
My 1998 12V has 286K on it and runs great (hope it stays that way)
anyways... I am no expert,but my guess is that with a diesel's high compression,it very well may be a head gasket. Especially since you have smoke from the valve cover area.
I wonder if you could disable the fuel solenoid and have an assistant crank it over and you watch/feel for air leakage during the cranking.
This is my 2cents worth....
again, I am no expert..
Good luck!!

 

I believe he has the problem solved...Just wondering the whys ,,so we were all discussing some possibilities, and a out break of head bolts ensued.
Like some one posted earlier lots of bolts ( and applications )are one time use only...
Being Cummings has a cardboard go / no go gauge some feel that they can be reused, pt is they can be,( if they pass the length guide jig) .Pt is would you want to ?
Lots and lots of parts where a extra safety of margin is employed "New Bolts " are specified . Fly wheel bolts,
Rod bolts, and the like .
These examples I am siting are not just for the C.T.D.
I could go on and on but is pointless as the example stands.
So "Do you feel Lucky" Go a head use the old bolts is basically the thought here ...........LOL

 

Thumper, MANY high performance engines reuse rod bolts for multiple rebuild cycles. They are carefully measured, recorded and measured for stretch at a given torque figure. Only if they stretch past the specification are they discarded.

There is NOTHING about "Do you feel lucky" in monitoring fastener life.

There appear to be many who fear the sky is falling though.

And there is no extra margin of safety with a "new" bolt, they have the same Kips rating as the old equivalent bolt, the bolt would only be derated for subsequent use if the Yield strength is reached.

 

I see that...
I am not accustomed to the way the threads are set up... I didn't notice that I was at the beginning of the series... I followed it up to the end and see ... I guess my suspicions were correct....
Glad he got it fixed....Cheap I hope

 

Thanks.

Cost around $1200. That included parts/labor. Parts included...NEW Head bolts and a new lift pump as well.

Also, included O-Ringing the block (while still in the truck).

Mechanic also blocked off the Waste gate and slid the AFC housing full forward. The truck already has 100HP injectors and a #10 fuel plate.

It was hitting upwards of 32psi boost before all this mess. Now it runs upwards of 44psi and NO real EGT issues.

Only real issue now is that it's overpowering the clutch! I guess I need to stick some $$ aside for an upgrade.

 

Your experience in life has been different then mine.
In my world I have had way too many bolt failures
As far as High Performance bolts we would have to get in a long debate as to what that includes
In race engines rarely will you reuse a rod bolt or a flywheel bolt.
In the Cummings Engines way too many head bolt failures
You are welcome to disagree with this..I do not want to get into Internet Rambo who is right / wrong
This has been my experience,yours may be different