6.4 headstud torque?

[ghohouston]

Pulling the cab and studding a 6.4 one at a time tomorrow, at the owners request. I remember 6.4's were cracking the blocks under the studs, so what is a safe torque to acheive with no worries of cracking? He won't be pushing a ton of power, going to some single h&s turbo kit, and h&s tuner.

 

[powerstroked08]

It depends on the studs. Arp with the newest lube is 250 on all studs minus the top ones that are in positions 2 and 4 if you count studs 1-2-3-4-5 across the top. Those are 225. If that makes sense.

 

[ghohouston]

I just read EVERY page of that cracked block thread, and i know what youre talking about, the 2ND hole in from either side, right below the lifter galley, where the block has less material. I'm not sure which studs he got, I know they're arp's, but don't know which specific ones. I know it will have a torque value listed with them, I just wanted someone with 6.4 experience to give me an answer. I've yet to stud a 6.4.

 

[ghohouston]

How about the "sequence"? This isn't my first stud job, but it will be my first time doing 1 at a time. I've heard some say only take the studs to 150 or something like that, and do each one that way, then go to 250 once all studs are installed at the lower torque.

 

[webb06]

i agree with above. do 3 steps to 225 then do an additional step up to 250 on all studs except the two mentioned

 

[powerstroked08]

How about the "sequence"? This isn't my first stud job, but it will be my first time doing 1 at a time. I've heard some say only take the studs to 150 or something like that, and do each one that way, then go to 250 once all studs are installed at the lower torque.

I have the arp stud sheet somewhere. Ill look for it. But I'm positive its 90# in sequence(inner ones first then working to middle then outter ones) then 180# then 275#(but we knock them down to 250 on the good holes and 225 on the weak ones).

 

[powerstroked08]

Here is how I did my studs one at a time. And for the record this isn't what most would reccomend BUT I have over 30K miles with them in with no issues. I know I'm probably missing some stuff but this is the jist of it.


Head studs
Before attempting to do my studs i bought about 3-16mm impact sockets(kobalt) just in case as well as 4-13/16 12 point sockets (craftsman) only because i have heard of so many people breaking them. I would also suggest locating a torque wrench that goes to 275ft/lbs (as dumb as it sounds i had a hard time finding one, all of the 1/2" drive ones i found only went to 250ft/lbs so i had to use a 3/4" for my final torque) and if you have a 3/4 drive make sure you buy a decent adapter to go to 1/2 drive unless obviously you have a 13/16 12 point 3/4" drive.
First i disconnected the batteries and drained the coolant(i put a hose on the drain so it didn’t make such a mess) then removed the driver side battery and reservoir along with both inner fenders. On the driver side i also removed the one Y coolant line that connects to the timing cover 2-8mm bolts. I then removed the air box and intake tube going to the turbo. Then i unbolted the oil fill reservoir 4-8mm bolts. Next i disconnected the heater hose from the plastic line on the top of the valve cover. Be careful with this because its easy to break, this plastic line will be somewhat of a nuisance when torqueing the studs down later. Then disconnect the glow plug harness at the front of the valve cover and remove the glow plug connectors. Be sure not to pull on the wires when unplugging the glow plugs. I popped the rubber grommets out of the valve cover a little bit and then pinched the T connector and gently wiggled and it seemed to work pretty easy. Now finish up disconnecting the rest of the wiring on the valve cover there are 2 connectors on the glow plug control box on the back half of it and one small one for your egt sensor as well as one last connector on the fire wall above the A/C accumulator. Next thing to do is unbolt the A/C accumulator 2-10mm nuts. Now there is one bolt to remove from the heat shield under the turbo and then pry up the shield to remove the bolt that holds the bracket to the valve cover 4-8mm. Now you should be ready to remove the valve cover 10-12mm bolts.(the bolts don’t come out of the valve cover so you don’t need to mark where the studs and bolts go) Now you should have access to the head bolts.I had a 3" and a 6" 1/2" drive extension on hand and a standard 16mm 6 point impact socket. Some of the bolts you can get with an impact gun but the rest i used a 1/2" breaker bar and a 3 foot cheater bar. Obviously be extremely careful breaking these bolts loose because there isn’t a lot of clearance near your injectors. I removed the bolts in the same order as the arp torque sequence and then installed the stud and used a 3/16 Allen wrench to hand tighten the studs in the block.( i prepped all of the studs with a light coat of oil on the coarse block side threads and then the moly lube on the fine head side threads of the studs and i also put moly on both sides of the washers and on the nuts) take your time tightening the stud with the allen wrench because there is oil in the bolt holes and it can give you a false sense of being tight. Then i tightened the nut to the first torque torque setting 90ft/lbs ( remember to be careful to not break the heater line on the passenger side head)then i loosened it up and retorqued again to 90ft/lbs and then torqued to the second torque setting 175ft/lbs. For the back bolts i had to jack the back of the motor up( i had the transmission out already so you can probably loosen the transmission mount and jack up the back of the transmission) And to torque the back bolts down especially the passenger side back lower stud i moved the A/C accumulator and torqued it through the inner fender its tight but it seemed to work for my truck. Once i had all of the studs in i went and did my final torque 250ft/lbs(225 in the weak holes) in the recommended order. Now the worst one i had to do was the back lower passenger side, and like i said i did that one through the inner fender. The one A/C line was in the way for my 3/4 drive torque wrench but i was able to use a regular short socket and slide the wrench under the line and do my torque. Now your done!

 

[madman1234509]

I'd torque them to whatever the sheet that came with the studs and lube says. Did both of my trucks to the spec With no issues. Biggest thing is to NOT OVER TIGHTEN, which means make sure you have a good torque wrench that is ment for the job, and is calibrated. Don't use one that makes out at 250-275 because they start to become inacurrate when they are maxed out. We bought a brand new one to do my job. Don't use a rented one that's been beaten/dropped/used as a hammer lol.

 

[powerstroked08]

I'd torque them to whatever the sheet that came with the studs and lube says. Did both of my trucks to the spec With no issues. Biggest thing is to NOT OVER TIGHTEN, which means make sure you have a good torque wrench that is ment for the job, and is calibrated. Don't use one that makes out at 250-275 because they start to become inacurrate when they are maxed out. We bought a brand new one to do my job. Don't use a rented one that's been beaten/dropped/used as a hammer lol.

I agree. That is a big part of it. I know when I did mine I did them to 275# and a year later the cracked block thread came up and I was like OH SH!T! what have I done! But I was VERY careful and I used a good calibrated torque wrench for my final torque.

 

[ghohouston]

So you actually bottomed the studs out in the holes? I thought that was a big no no?

 

[78f100]

you need a good tq wrench and the correct lube, but I think blocks cracking is luck of the draw , casting issues. Mine cracked with A1's at 190ft#. I did the same thing you are doing for a friend a whe back. We pulled them 1 at a time, torqued to 200iirc in 3 stages then final tq to 250 with the exception of the weak holes we brought them to 225. He beats the crap out of this truck with no issues so far.

 

[powerstroked08]

I threaded them in untill they bottomed out then I back them off 1/4 turn.

 

[powerstroked08]

you need a good tq wrench and the correct lube, but I think blocks cracking is luck of the draw , casting issues. Mine cracked with A1's at 190ft#. I did the same thing you are doing for a friend a whe back. We pulled them 1 at a time, torqued to 200iirc in 3 stages then final tq to 250 with the exception of the weak holes we brought them to 225. He beats the crap out of this truck with no issues so far.

I would really like to know what the clamping force is for each bolt. I say this because H11's are a harder bolt and therefore streach less than an ARP. So with that in mind, the H11's torqued to 190#'s could quite possibly have more clamping force applied to the block(since the bolt is "giving" less and pulling on the block more). So even though the H11's are torqued to a lower value they could very well be pulling on the block threads as much or more than an ARP at 275#'s.

 

[madman1234509]

^^^ exactly.... Also, if its done and you have no issues than you probably wont have a problem. If its going to crack, it'll do it on the install and you'll get symptoms right away.

 

[78f100]

I would really like to know what the clamping force is for each bolt. I say this because H11's are a harder bolt and therefore streach less than an ARP. So with that in mind, the H11's torqued to 190#'s could quite possibly have more clamping force applied to the block(since the bolt is "giving" less and pulling on the block more). So even though the H11's are torqued to a lower value they could very well be pulling on the block threads as much or more than an ARP at 275#'s.

Mine were Elite's A1 tech studs, in the beginning they were said to be better than ARP. It was later brought to light they were both made from 1722 steel not h11 tool steel. The stretch would be very close on both the big difference in tq was the lube. The a1 studs used the old ih compound 2 most old guys called peanut butter. I have studded many since mine with no issue, I really think it was a weak block from the start.

 

[4.0l sahara]

Arps do 250 and 225 on the weak holes.

 

[powerstroked08]

Mine were Elite's A1 tech studs, in the beginning they were said to be better than ARP. It was later brought to light they were both made from 1722 steel not h11 tool steel. The stretch would be very close on both the big difference in tq was the lube. The a1 studs used the old ih compound 2 most old guys called peanut butter. I have studded many since mine with no issue, I really think it was a weak block from the start.

Ah, I gotcha.

 

[78f100]

There was a big deal made about the elite studs being advertised as h11s back then. I thought they were h11 when I bought them, but found out later they are not. I think Elite does have some actual h11 studs out now. The tq on them should be less like you said because of stretch.
I won't lie every time I stud one I get nervous about cracking the block, because how easy mine did it.

 

[DWhite]

Just some info if people are looking. I bought some Extreme Studs from Mike @ No Limit and the final tq is 180-185 and at that tq they are suppose to have a better clamping force then ARP. So the 180-185 would be safer if you're worried about cracking a block.

 

[madman1234509]

Just because its torqued lower doesn't mean it's safer...