retorque head bolts?

[Oskar]

Hi, just got my truck running again, i've torqued the head bolts as described in service manual, 1'st step 90Nm 2:nd step 120Nm (checking the torque after each step) and then additional 90deg. i saw in another thread that some of you recommend retorquing the bolts after some miles, well, the engine has been running 10-15 hours after assembly now, so i will recheck the valve play, and if necessary, retorque my bolts, but what torque should i use? someone says "135" but do you mean Nm or ftlbs? please give me some advice here thanks

[Deathrod]

Stock bolts? I've heard 115-125 ft lbs for stock bolts. I wouldn't go much over that especially if there well used. Just my 2 cents.

[Oskar]

hi! yes they're stock reused bolts.

[PToombs]

A retorque is a good idea, especially if you plan on hot rodding with it. Retorque before you readjust the valves.

[Tacoclaw]

Alex was saying somewhere a while ago that he did the normal torque routine and it took more than 125ft/lbs to break them back loose again.

[CumminsPower59]

I'm fixin to do a re-torque too, should I do it with the engine stone cold or could it be done slightly warm? The reason I as is where all my tools and work area is about five blocks away...so I have to run The Pile over there to work on it...

[Tacoclaw]

Mine was done cold, the only recommendation I have is to wire wheel the bolt threads spotless, then give them a light coat of 15/40.

[CumminsPower59]

The ones in the 91 have never been out as far as I know...so should I pull them up to 125, or pull them out, one at a time and clean/lubricate/torque?

[Tacoclaw]

Pull them one at a time in the torque sequence, clean, lube, then retorque.

If you just try to retorque them I doubt you'll get anywhere. The ones along the exhaust side of the head get super rusty.

[CumminsPower59]

Right on. Gives me something else to do before S.O.P....swap injection pumps again, injectors again, finally install a clutch, and re-torque headbolts

[Oskar]

hi. tried to do the re-torque today, first i took out the #1 bolt (between cyl3&4) cleaned and lubed it, but when i was about to drop it back i saw that coolant was seeping out of the bolt hole, so i took the vacuum cleaner and a 10mm hose tpo suck the coolant out, then i mounted the bolt quickly and torqued it, set the torque wrench to 170Nm first, but it felt like i was going to break it, i lowered the torque to 160Nm and the wrench clicked, then i set it to 165, and i did turn the bolt almost a 1/4 turn without reaching the set torque, so i gave up, i just dont want to snap a bolt..
i did torque the other bolts to 170Nm without removing them, some of them (in the middle) could be turned up to a 1/4 turn before reaching to that value, and some of them reached it immediately.

[CumminsPower59]

I tried to do a full re-torque...got to bolt #22...snap. New gasket and bolts will be in Monday sometime, I'm just gonna go to 115lb ft this time and not 125. Also, I had a bolt stretch in almost the same location, (between cylinder 2 and 3), acted the same as you described...

[Diesel]

Sorry but retorquing used stock bolts is a horrid idea. They have already yielded. Ideally you would use studs so the torque is actually even but if not then new bolts are the minimum. Running a head that has bolts at different torque could cause warpage...

[RCCUMMINS89]

I agree that "on paper" it is a horrible idea.

But a LOT of people do it and have good luck with it. I think most do their own little voo doo dance and are fortunate.

[Diesel]

I'll concede with the voodoo dance tangent added. I've made a lot of things work that shouldn't have until the voodoo addition.