H-11 headstuds breaking!!!!!

Ether Man

Ether Man

The Racer Formerly Known as ConcreteBlockHead, who
Joined
Jun 26, 2006
Messages
414
anybody have bad luck with haisley h-11 12mm headstuds breaking? i just found my second headstud laying underneath the truck!!:nail:m Both that have broke have been on the exhaust manifold side, first was at the number 2 cylinder and today walked by and seen one laying under the truck and it is at number 4. Both broke right in the middle of the stud, the studs have less than 2k miles on them. Just wanted to see if anybody else has had this trouble. Everything was lubed properly and bottom tapped and blah,blah, blah.
 
I hardly made any power compared to you when I had my 12mm H-11's, only about 750hp but I never broke one. I haven't had a chance to try out my 14mm H-11's yet though.
 
little6cylinder said:
I hardly made any power compared to you when I had my 12mm H-11's, only about 750hp but I never broke one. I haven't had a chance to try out my 14mm H-11's yet though.
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sorry, i should have stated this is on my 350 horse 1/2 ton conversion. i am debating each time one breaks putting a head bolt in it's place. the studs are breaking in the middle not in a thread. the truck hadn't been drove for a couple of days and then this was under it, are these things under so much strain when they break it is popping up and falling off the motor?
 
I had 2 H11's break and 1 ARP(not 625) break.
 
I had 4 break only torqued to 135ftlb over about 6 month span. I took the rest to the scrap yard and went with arp625.
 
had two break on my last truck. not positive now of final torque but somewhere around yours. funny thing was, stuck two stockers in its place to get it mobile and they were fine using the 5lb garmon method
 
H-11 is very brittle when cold. Also might want to check your TQ wrench.

ARP makes a stud similar to the H-11, IIRC it's the 625 space age stud, never had one of those break.

Just a thought.
 
well damn. This kinda sucks, I hope none of mine break. I've torqued them twice so far, one hot, one cold at 140 I think. I'm kinda scared to pull on em more now?
 
BC847 said:
Call Vann Haisley. He'll get you straight.

Haisley Machine, Cummins diesel performance for Dodge trucks, everything for your project, a little or a lot - Haisley Machine

Haisley Machine
8231 S 200 W
Fairmount, IN 46928
Phone 877-948-3164
Fax 765-948-3163
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oh i will be tomorrow, first one i figured no since in arguing over whether i done the procedure right. i have done this multiple times, but 2 to break and i haven't torqued them for 2 months and now i just walk out to drive the truck and a stud just happens to be laying underneath the truck.
 
not to get off topic, but has anyone tried the DNR Customs head studs? They claim to be the exact same thing as the ARP 625 studs, but almost half the price.
 
I know it's a big difference but, I've torqued my 14mm's to 150 many times and never had a problem.
 
Subscribing. I've got a set fixing to go into a 6.7
 
hopefully i will get ahold of somebody today, just wondering if the heat has anything to do with it? just funny that the only ones that have broke have been the ones along the exhaust side.
 
I know the studs in the water jacket are prone to rusting..... maybe that's what happen ? I completely coat those studs with ARP lube which I think has help keep the rust at bay on those studs.
 
i was kind of thinking the same thing, but with only 2k miles on them and they are breaking.................might not be a good choice to leave them in there.
 
ok, so i got ahold of bryce this morning at haisley's and we started diagnosing with van. my instructions from about 2-3 years ago said torque to 140, now the instructions say to torque to 130. needless to say they are going to send me a new stud and i am gonna send the two broken ones back and they will send them on to A1. so my thinking is to back them off 1 at a time and set at 130 but van thought they would be ok but i am not feeling so lucky.
 
Ether Man said:
needless to say they are going to send me a new stud and i am gonna send the two broken ones back and they will send them on to A1.
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Good deal. I knew Vann would fix you up. They do try to keep the quality control up to par.
 
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