As the title implies, I can't let it go in it's present condition. Another ARP stud broke while driving. This one is near number three cylinder exhaust flange. Both studs that have broken are the short studs near the exhaust manifold. I extracted the part remaining in the block and lucky for me the piece that broke off landed on the engine mount. I found it by accident when I was starting to change the heater blower motor. I saw steam climbing up around the passenger side of the head gasket. So, now I need to do another head gasket after I express my total lack of faith to ARP. The first stud that broke in 2018 was do to lithium stress corrosion according to the fellow I talked too in CA. They replaced it for free. The head gasket didn't leak on that incident. This time it is different do to the leak. I torqued the studs to ARP's specs and used their ARP 2000 lube. Needles to say, I am not a happy camper.

 

That sucks! What fasteners are you going to use this time then?

 

Is this a common thing? I don’t hear/read of studs breaking.

 

Apparently it is a more common thing than they want to admit. In conversation with the gentleman from tech support he mentioned that the studs closest to the exhaust manifold tend to fail more often do to hydrogen embrittlement accelerated by high temperature swings. I sent the broken parts to California yesterday. They should arrive on 2/22/2022. I will let you all know the outcome then. As far as what to use next........any suggestions.
ARP kit number 247-4203 is NOT my first choice. Thinking maybe 247-4205. They are twice the cost but maybe they can handle a little coolant. But I have seen the diesel guys on U-Tube break them too.

 

ARP got back with me today after they received the broken stud. Corrosion causing hydrogen stress fracture seems to be the cause of failure. Sam made me an offer I couldn't refuse. They are sending me the high end stud kit for a very reasonable price. I should be getting the new studs in about a month. He told me that the kit that I bought are not much stronger than the stock bolts. Their advantage is they are reusable whereas the OEM bolts are not. When torqued to 125 ft:lbs they give only marginal more clamping force than original. Not being able to calculate total lift at 43 pounds boost and timing to the head he figures I overworked the studs allowing the head gasket to leak coolant into the cavity where the studs pass through the head thus contaminating the bolts allowing for corrosion.
Bottom line. Don't go with the less expensive studs if you are planning on serious horsepower. Unless you really enjoy tearing down your engine more often.

 

I am changing the thread after this. I plan on taking my time and redoing the head gasket along with some other mods to increase horsepower and drivability.

 

Of course they won’t advertise this. Had I of known they are not much better than stock for clamping pressure, I would have either stuck with stock or opted for something that is a bit better than marginal.

 

I'm looking at a better solution vs cost also for a mild build. I don't want to use stock TTY headbolts, but alternatives are few and far between it seems.

Socket head cap screws from McMaster are available in correct lengths and 12.9 hardness. I may use them with a hardened washer under the head.