Head Studs Won't Torque

Q

quickmfg

Junior Member
All,
I'm putting together a 59A I've just gone through, and I have reused the original head studs, replacing a few damaged ones with other spare used ones so that all are in excellent shape with good threads. Stock 59AB iron heads.
I cannot get most of the studs to more than 52 ft-lbs without the studs feeling like they are stretching/yielding. I tried a few in a cracked block, and 60 ft-lbs will break them clear off.
I am using new plated nuts from Mac's and 10W-30 on the threads and nut faces. Has anyone else seen this?
I have one head on and all the studs took a solid 50-52 ft-lbs. I have yet to do the other side. Should I pull it back apart and replace all the studs?

Who do you recommend getting studs from?
 
totally a guess, but perhaps your studs were once subject to so much heat that they lost their temper? Did you use loc-tite on your studs? Another possibility is that at some time your stud holes filled with debris or rust. Mayhaps a stiff wire and air pressure would tell if that were the case.
Perry in Idaho
 
Everything is perfectly clean.

I was trying to get to 55. Wrenches are good. I borrowed another today that is calibrated as well to check. Right on. Thanks for the replies guys.
 
I ran into this when I rebuilt my 59AB that is in my 37 coupe. I thought that no one today made the head studs as good as the originals and they looked good to me so I cleaned them all up and even bought one of those kits from Eastwood to refinish them (blacken). When I got the engine back from machine shop and assembled studs in the block everything still fine until I was torquing the original heads down,most held up fine but a few would not torque correctly and I could tell they were stretching,I think one at least twisted off below the head and I had to remove the head to get to the stud, lucky ,broke on the threads for the nut,not threads in block but looking at a couple others you could see stretching or distortion. The studs all came out of this block very easy when tearing down,nothing tough or snapping off, for some reason they may have been anealled or never heat treated to begin with. I removed all and put in a set from Roy Nacewicz,fit and torqued up fine. Again I really wasn't trying to go cheap I figured the original ones would be the best.
 
Mine on the 8BA in my '36 pickup are the same way. I figured it was because I chased the threads with a regular tap when I was cleaning everything up. That was before I learned not to do that on this forum's predecessor. And yes, I run studs on my 8BA because I want to.

I put shoulder washers on my builds and torque to 50. Re-check annually.
 
I torque ALL my head bolts/studs to 45 ft/lbs for 3 heat cycles. This produces more clamping force than a blown 392 Hemi on 100% nitro.
 
Not sure if the threads want to be oiled or dry when torque-ing, or if that is even a factor, but it seems like that may affect it. Maybe someone here has better information on this.
 
Bishop Welding said:
Not sure if the threads want to be oiled or dry when torque-ing, or if that is even a factor, but it seems like that may affect it. Maybe someone here has better information on this.
Click to expand...

Hmm, never saw anyone 'oil' the threads...where the nut clamps down on the head. I use never seize on the lower portion on the stud hand threaded into block (to prevent studs from rusting in place).
I would think that the oil would change the originally intended (torque)twisting/tightening force..to who knows what effect:confused:
BTW why use used/questionable studs on an expensive job otherwise?
I may be overly cautious, but use the best new set of studs that I can get. I consider the wear/tear between the old stud and the block threads. I figure that some of that wear is taken up by use of new studs..no?
 
I think that to torque something correctly it should be "lightly oiled". I must have read it somewhere, I'm not clever enough to make stuff up.

Mart.
 
I have seen different torque specification's DRY would be a little lower.
WET ( lightly oiled ) a little higher.
If I remember correct on a Mack truck they wanted you to put the stud into the block dry & tighten hand tight then back it out 1/4 of a turn and then lightly oil the top thread and torque it wet in 3 steps to get it to max. tourque.
(But then again that may have been a bad dream I had after I ate a Burrito just before bed.) LOL LOL
 
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