after much deliberation i plan on retorquing stock head bolts to 133lb-ft and then bumping timing to something around 16.5*. the question is though should i retorque on a cold motor or a hot motor, or does it matter?? is there any need to completely remove each bolt before retorquing or just put the wrench on and call it good?

 

Bump, I'd like to know this too please.

 

On retourqueing I have read cold motor, torque in increments to max.

mark position of bolt, if it turns more than 120 degrees, replace it.

No need to remove them if they reach torque before stretching too much.

Let some more advice roll in though, to be sure.

 

i have thru various inputs and research decided that torquing should b around room temperatures. not wit it hot and not when its -20 either. Wat do u mean by torquing in increments? also is there a torque sequence to following during retorquing or does it matter?

 

Upon cold start, I'd run the motor 2-4minutes as it doesn't take long to begin warming up-or- until the valve cover began to warm.Then retorque to spec based on the recommended tq sequence. Sorry I don't have that sequence but now that you know its 133ftlbs, you s/b able to find it. I'm @ 214k, I should probably do mine also. JMO.

 

..........Is retorquing, something thats recommended at certain mileage intervals.....would a guy be better off to change the bolts, or get studs.......thanks.......kim....

 

retorquing is probably not necessary on a stock truck (my opinion only) but it'll help hold the gasket down for a bit if ur increasing timing and/or boost, both of which i am. head studs would b ideal but not feasible for me right now so mild mods and retorquing it is.

 

stock torque is 66ft lbs on all bolts recheck 89ft lbs on just the long bolts recheck then turn all bolts 1/4 turn without torque wrench doing this in a circlier pattern from center out. Personally I have never retorqued but not against it but I don't think I would torque the short bolts to 133ft lbs.

 

many different takes on the actual spec. iv heard stock cummins spec is 115, chilton manual says 60/89 +90* turn, a diesel mag says they did 125 safely, while other ppl say theyv taken it up to 150 whatever u feel u wanna risk i guess lol

 

DC199512V87 , I think if when I was gonna modify from stock settings I would use a Cummins manual for torque specs and patterns/sequence only and not go by a magazines suggestions.

If you are gonna bump the power levels significantly I would get head studs first, followed by fire rings and then whatever breaks after that.

Some/ a lot of head bolts will not be within spec after thousands of miles and could probably use some cinching up, but taking a bolt to 133# that's spec'd at 90# may find you fishing out the broken end !!

I'd first check them to the spec'd max and see where they are, marking them beforehand to see if any were really loose, then pull and inspect/replace those.

 

well as u suggested cummins manual says 115 lbs so 18lbs over is not that much in all honesty. i don't like the 89 lbs over+ 1/4turn cause who really knows how many lbs a 1/4 turn gives? that sounds like guesswork to me personally lol a lot depends on the condition of the threads.if retorquing and the bolt doesn't move at all or keeps turning but not tightening (stretching) then removal and replacement or further inspection is necessary. but at a minimum replacing stock bolts is a sound idea

 

Torqueing is one of the least accurate ways of tensioning a fastener. The best is to measure the actual stretch. Using the torque turn method is more accurate than torqueing alone, as it eliminates any false tightness you'd get from a burred thread or poor/lack of lubrication on the threads.

 

True stuff - I have been seeing lots of newer stuff call for X ft-lbs + X degrees. Knowing that lube and burrs are less prominent effects at somewhat lower torques, it is very accurate to use a torque wrench to get part of the load, and then use the pitch of the thread and a known amount of rotation to get the desired stretch/clamping load.

There are even torque wrenches that measure the angle for you:
http://buy1.snapon.com/catalog/item....re&dir=catalog

That said, until Cummins re-writes their manual, I'm going to stick with the 115 ft-lbs in the manual.

 

Thanks for the Tq spec clarification...I was just going off of this thread!