How many guys have used the ARP Studs?

[sle2115]

2115,

The "one guy" was the Tech at Hypermax that has done hundreds of turbo installations on 6.9-7.3 IDI's. I would consider his information much more credible than the typical self appointed internet expert you see that has a opinion on everything. Not to say the guys you got that information from were wrong but there is a lot of difference in the experience level of the information providers we are treated to. Regarding head bolts, he said used head bolts did not need to be replaced with new ones. They do not wear out.

Well one of the guys I talked to has probably built as many engines as anyone, including the Hypermax tech. Has been an engine builder/machinist for about 35 years and one of the others has been building hiperformance engines for about as long, including many 6.9/7/3 IDI pulling trucks when those were the "hot" diesel engine - pre cummins/dodge and ford/powerstroke. The other pulls trucks and tractors and has ARP's in the 3 - 6.9 engines he pulls with. Personally, the techs I talked to at Hypermax were just that, Hypermax techs that had limited if any real world experience. They could read the books, and had installed a turbo or two, but did not have the experience the guys I talked to in the last year (planned to do my head gaskets as well so I inquired from them), so maybe you got one with real world experience. The guys I spoke to were also my mentor's throughout my career and I pretty much take what they say as gospel. I just talked to one today, I will spare you what he said about the Hypermax techs information regarding 6.9 head gaskets!

Honestly, I am not trying to argue, but I have seen these three guys in action, I am assuming you are just talking to a guy that "says" he has done this work. I should also mention that I never mentioned turbo on my truck, cause while I would like to have one, I just never planned on spending the money. This was all discussed as on an NA motor, which is what I have.

 

[The Warden]

And you did yours up to 90?!!

I'm thinking more like my torque wrenches are way soft, so that I'm setting them to 85, but they're only clamping to 50 or so. That still doesn't make much sense, because you'd think the studs to 50 would probably still hold the heads down better than the bolts at 80.

That was (sort of) based on ARP's recommendation, and was actually a compromise. The ARP installation sheet states:

Torque vales are based on 75% of the fasteners yield strength. Use the manufacturers torque sequence but do not use the engine manufacturers torque specs. Torque the nuts to 70 ft lbs for ARP MOLY ASSEMBLY LUBRICANT (or ARP THREAD SEALER) or torque to 85 ft-lbs with 30wt motor oil. {emphasis in original}

I used 30 weight oil on mine.

As to how I got the 90 number...that was based on ATS's instructions to add 10 ft-lbs to the torque already being applied. I felt uncomfortable with putting 95 ft-lbs on the stud nuts, so I called a technical type at ARP and we discussed the issue, and determined that 90 would be a good compromise between the two. Then, I brought the torque to 90 in a total of 8 steps...following the 4 steps outlined in the FSM to get up to 75 ft-lbs, then torqued and re-torqued to 85 in the line sequence, then torqued and re-torqued to 90 in the line sequence. I was REAL careful...and used a brand-new Snap-On torque wrench that my auto mechanic buddy hadn't had occasion to use yet.

I can't wait to hear what happened, but, yeah, I really don't think the studs were the problem...

BTW, in response to a comment about "self appointed internet experts"...based on what I have seen and heard from some professionals (and, note that I said "some" and not "all"), there are many times when I personally would trust a group of "internet" experts over what a professional has to say. Specifically, with this site, many of the people here have been there and done that...learned lessons, ON THESE ENGINES, the hard way. To me, that counts for a lot, particularly considering that there are very few professionals who can legitimately claim that they know the IDI engine inside-and-out and specialize on these engines alone. That said, again personally speaking, I generally don't act on the word of one person alone...prefer to get a general consensus from people before taking any action.

JMHO...

 

[RLDSL]

Warden

Thanks for that info, and



You're absolutely correct. I pulled 3 separate studs this morning, one at a time, and did measurements. I measured the depth of the holes, the length of thread etc to compare the 2. What I found, is that the bolts don't bottom out in the holes. If they have a washer on(I can't remember if they do), then they're about 1/2" short of the bottom of the holes. If not a washer, then yest, 5/16ths, and turns out, the studs run out of thread before they hit bottom too, but they also have about 1/4" left.

I can't imagine in any way that the studs could be responsible for these symptoms. The only thing I can think of, is that if somehow both of the torque wrenches I've got (one is a snap on, one is a proto-professional)were out by a lot, then I might not have got the torque right. I just can't make sense of that, but I guess I'll have to see about getting one of them calibrated to be sure.

Since the clamping force of the studs is much more than the bolts, could it be that studs torqued to 85 is so much more force on the heads that it could crack the heads? I just can't see it. And you did yours up to 90?!!

I'm thinking more like my torque wrenches are way soft, so that I'm setting them to 85, but they're only clamping to 50 or so. That still doesn't make much sense, because you'd think the studs to 50 would probably still hold the heads down better than the bolts at 80.

Heck, I dunno, now I'm just rambling....

Zigg

Hey Zigg, something just came to mind.
How cold was it where you were when you initially torqued the studs down?
When it gets cold out clicker torque wrenches go buggy and generally take a lot more pull to get the cold spring to click over than they do at room temp. I learned that the hard way after twisting some bolts off a bunch of years ago, and always put the torque wrenches in the house and get them up to room temp when it's cold out, and if it's real cold, I'll take my time and make a few trips back to the house to warm them ( and me up
Even at 35-40 deg f the things will read off.

Just a thought-------------Robert