Breaking head bolts every time

( dodgeram.org/tech/specs/bolts/M_bolts.html )
( www.fastenal.com/content/feds/pdf/Torque...tric%20Fasteners.pdf )

It's helpful to hear that the torque specs are wrong. I'll go up to 18 or so with the ones I have on the way in the mail.

Is it madness to torque the head nuts to 30? They seem to hold up to it pretty well...

Sounds like two passes for the nuts, 18 lb ft first pass, 29 lb ft second pass in sequence both torque settings, may be a good idea to recheck the 29 after a couple of warm-up and cool-down cycles so they don't loosen. Don't forget on the bolts, your going into aluminum, it pulls threads out easier then steel or iron, think i'd stay around 15 lb ft or a little less.

tinlizzie37 wrote: I would never replace any of the bolts with stainless. Most stainless steel is much softer than carbon steel ones. That's probably why they broke off. You can see the stretch that caused it. Bob

are we going there again? theres not a hardened bolt anywhere on these bikes from the factory,even the main cap bolts on a 900/1000 are like a grade 2 bolt! :woohoo:

staniel wrote: It's helpful to hear that the torque specs are wrong. I'll go up to 18 or so with the ones I have on the way in the mail.

Is it madness to torque the head nuts to 30? They seem to hold up to it pretty well...

i would stick to the specs for the nuts. 29 is not too much for them. i have APE heavy duty studs in my KZ1200, as do all guys who biuld big motors. they are speced at 42 ft lbs. and they do not pull out of the aluminum cases.
if u go light on them u may experiance head leaks.

mark1122 wrote:

staniel wrote: It's helpful to hear that the torque specs are wrong. I'll go up to 18 or so with the ones I have on the way in the mail.

Is it madness to torque the head nuts to 30? They seem to hold up to it pretty well...

i would stick to the specs for the nuts. 29 is not too much for them. i have APE heavy duty studs in my KZ1200, as do all guys who biuld big motors. they are speced at 42 ft lbs. and they do not pull out of the aluminum cases.
if u go light on them u may experiance head leaks.

Yeah and the studs get torqued to like 20-22 ft-lbs

Andy9802gt, What is the cause for the discrepancy between 29, the spec, and 22, the torque on the studs? That the friction of the nut on the washer adds an additional 8 ft-lbs?

staniel wrote: Andy9802gt, What is the cause for the discrepancy between 29, the spec, and 22, the torque on the studs? That the friction of the nut on the washer adds an additional 8 ft-lbs?

u are looking at 2 dif specs. 22 was for the bolts, 29 was for the nuts.2 dif sizes

K, I was confused by Andy's wording. He meant the head bolts are 22 and the head nuts are 29. My understanding is that the studs are the threaded rods that come up from the crank case and the head nuts tighten onto them.

staniel wrote: K, I was confused by Andy's wording. He meant the head bolts are 22 and the head nuts are 29. My understanding is that the studs are the threaded rods that come up from the crank case and the head nuts tighten onto them.

OK U HAVE ME CONFUSED NOW. LOL
when andy was replying to my post he meant the studs which thread into the cases are only torqued to 22ft. lbs. (because they go into an alum case). and the nuts that go onto the studs get torqued to a higher #. (29lbs.) in your motor. 42ft.lbs in mine.
i think thats where were at now

That's what I meant mark

I finally got a pair of replacement head bolts. I have a spare set sitting on my desk and more on the way. I will never reuse head bolts again. These things are clearly designed to be one-use.

I used my nice torque wrench to torque them up in 15 in-lbs increments, starting at about 100. The first one made it to 240 (20 ft-lbs). The second one got up to about 200, then when I turned the wrench up, it spun farther than it had on previous torque increases, so I stopped, landing somewhere around 216.