Head bolt retorque?

J

jdog56

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Nov 22, 2007
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Hey guys i figured i'd ask you guys before i tear into the mighty dodge again. My question is should i retorque my headbolts, and if so what should i torque them to? I run about 40 psi daily with it on a stock gasket and bolts. I do have a 21 cm2 exhaust housing on it from a 1st gen to help keep the drive pressures down, the pressure is roughly 55psi at 40 psi boost. thanks,jesse
 
jdog56 said:
Hey guys i figured i'd ask you guys before i tear into the mighty dodge again. My question is should i retorque my headbolts, and if so what should i torque them to? I run about 40 psi daily with it on a stock gasket and bolts. I do have a 21 cm2 exhaust housing on it from a 1st gen to help keep the drive pressures down, the pressure is roughly 55psi at 40 psi boost. thanks,jesse
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We run stock head bolts to 95 lbs. Never hurt to give them a check or retorque here and there
 
21cm!!! Dang that's big. Anyway, I don't see a problem with a retorque. I followed the factory torque specs on my headbolts (new) and haven't had any problems yet - knock on wood(three times)
 
I have retorqued a couple to 120, and it seemed to hold the 50 PSI no problem.
 
Not to HJ but how is that housing? I'm guessing it dropped EGTs a bit, how bad did it hurt spoolup?
 
Ken in AZ said:
21cm!!! Dang that's big. Anyway, I don't see a problem with a retorque. I followed the factory torque specs on my headbolts (new) and haven't had any problems yet - knock on wood(three times)
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21 :eek: I wonder on spool as well?
Brandon
 
I was wondering if anyone was going to mention that housing, lol. The spoolup isn't that bad, it'll wait till roughly 1700 rpm then lite like crazy. The truck smokes like mad and will dim the brightest of highbeams behind ya! Thats mainly due to the freebie full cut delivery valves i have :doh:. The EGT's will bury the 1500* pyro pretty quickly even with the large housing, i did the housing to help bring down my drive pressures that were hovering at about 80 psi at 40 psi boost.
 
what are your drive pressures now?
you should fill out your sig so we know whatcha got goin.

I retorqued my stockers to 115 so far. someday I will probably go up to 120 or 125. I marked them before I started and at 95 some of them didn't even make it to the original mark. at 115 they are all about a 1/4 turn past what they were at before.
 
When retorqing stock bolts are you guys breaking them loose first one at a time then torquing them to 120 or do you just start from the center of the head & work your way out tightening in 5 lb increments.Could somebody please explain the exact procedure as ive read several differant methods.Thanks.

Kurt
 
Stop being cheap and buy headstuds. When you end up breaking a head bolt off in the block its gonna end up costing more than if you had just done studs to begin with. Just my opinion though.
 
Stock head bolts are Torq To Yield . This is the reason Cummins gives you a head bolt length go no go gauge , this is if you are reusing the bolts. I never reuse them , and if the customer does not want to spend the money on studs we buy new bolts. Then torq them to in three incriments. 75,95,120 then 90 degrees past that.
 
I torqued a set of stock new bolts to 120 and it felt like they were stretching, then I went to do a warm torque and broke the first one I put the torque wrench on and that was just to 120. I could feel at least half of the bolts stretching, so I pulled them all out and put studs in it and torqued them to 140.
 
so how is it done again? break the nut loose then tighten to 75. repeat on each, one at a time. then do 90. then do 120? or should i just break it loose and go straight to 120?

Garrett
 
SSpeeDEMONSS said:
so how is it done again? break the nut loose then tighten to 75. repeat on each, one at a time. then do 90. then do 120? or should i just break it loose and go straight to 120?

Garrett
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I go in the cummins pattern. Break one loose, lube it, then retorque to spec and go on to the next. I went to 125 with my stock headbolts no problem, others have gone much higher.

Another common practice is to not back them off just pull on them. But then you get into the breakaway vs static debate. Both have been successfully done, both have failed, take your pick.


If you only go to 75 with them you will likely compromise the headgasket, trust me.

:Cheer:
 
a friend of mine had darren in ga torque his to 130 and he pins a 60 lb gauge not knowing wat hes boosting and it holds! stock bolts and gasket! make sure you let them settle between torques.
 
Ask 17people you get 17diff answers on this.
Diesel power magizine website has a pretty good write up about this under the tech section part. It goes over 2 diff ways got pics ect.

I took each headbolt out one at a time and oiled them in 30wt oil. cold moter
Tightened it back to 85 or 90 dont remember exactly now
After all were oiled and at 85/90 i started going in 5lbs inc by in the middle working out like the repair manual says
Once I got to 100 or 105 I took a paint marker and drew a line so I could tell if one was turning further (streching ). They all stayed in line till 120 and a couple were wanting to turn more than the others so I did a few at 125 and fiqured I would quit while I was ahead.

So far its been holding 38-41psi fine
 
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