ARP head studs & Re-torqueing after heat cycles (what spec do you use?)

[turboglenn]

Here's something i've pondered for years and have enver found a definitive answer (even from ARP )

With the ARP lube you are supposed to torque them to 80ft/lbs, but with motor oil you're told to go to 120 ft/lbs.

So, if you've assembled the motor and torqued the head with ARP lube, then put a few thousand miles on and want to re-torque the head, What torque spec do you use?

I ask because in theory there should be some ARP lube still on those threads, BUT, what about the oil from the engine that gets spalshed on the studs and makes it's way down the threads and what effect does it have on the value you should re-torque to?

TO be honest... I have always just done the 80 on first assembly, then when re-checking them after the engine has ran I use the 120 based on my thoughts of the engine oil washing away the ARP lube after some time. Now, I've never had them turn any more than MAYBE an extra ~2 degrees on the 2nd torque when using the 120ft/lb motor oil spec if it's been more than a few days since orignial torquing. But with this new built motor and my now very thin wallet, I don't want to take any chances and would like some input from others as to what spec you used and were there any negative results with either one?

It's not that i don't know what i'm doing, but this is something i've NEVER found a clear answer to. ARP can only suggest to completely clean the threads, apply either lube and torque correctly, but that eliminates the purpose behind "re-torquing" in the first place IMO. (but I have also thought of maybe doing it that way one bolt at a time, but still am unsure) If nothing else i'll just go 120 like i've always done and call it good.

The last time i re-torqued them was back in December '08, and i just checked them at 80 ft/lbs since there was only a few short cycles on the engine and i felt there was still ample moly in the threads. But by now I'm pretty sure the moly lube is probably diluted and washed away almost completely at this point.

 

[pboglio]

I torqued to 80 lb-ft, then still kept pushing a little coolant for a few days. Then retorqued and the head gasket to 85 lb-ft or so and it sealed up. I wouldn't torque to 120 lb-ft as that is 50% over the rated torque with molylube. I believe the 80 lb-ft is at 70-80% of the yield point of the bolts with molylube. Washing away of the molylube is an interesting theory, I personally wouldn't know, but I doubt the engine oil could displace the moly lube under that much load pressure.

 

[turboglenn]

Well, on the last engine i did them at 80 with molly lube, and then a few years after the initial retorque, i set the wrench to 120 lbs and they didn't even budge except like i mentioned a few of them MAYBE went a degree or 2 and the wrench clicked so in THAT case the molly had been washed away, and I did that one was because i was pushing coolant.

Right now everything is fine and it runs great, but i'm about to add laughing gas to the mix (already installed and programmed actually) but I don't want to spray it until i double check the head bolts since the motor is fairly fresh and i used a stock gasket on purpose as a "weak link" so it would pop rather than something else if it came down to it, and i just wanna be tripple sure that when i start juicin 'er up that i don't pop the gasket because of it settling in.

And honestly the only real reason I want to tripple check is because i feel the initila re-torque was done a bit early (only about 3 heat cycles and 15 miles on the engine), but i was in a rush to leave town to get married in TX and drive back to omaha and haven't checked them since and now have put maybe 4-5k miles on it, so i'm prety sure the gasket could have settled more, but it's not pushing any coolant or anything thankfully, and i've been beating her hard lately There's just something so cool about being able to roll on the gas at 60 in third and hear both tires scream and squeel as the tach heads for redline (like it use to do in 2nd)...and so everytime i pass some one on the interstate now i have to do it burning rubber, or at least let them start to sqeel then shift

God i love my car again now that i've put her back together from a 4 year spell of neglect after my injury in 2005 that left me unable to push the 2600lb clutch for over a year. So the car stayed parked and i had (past tense) lost interest until last year when i started building and fixing her up again....

Now i am trying to get her fully tuned on the bottle so i can buy slicks and hit the track (and not wanting to break anything till i've made some passes at least).. i've already got it tuned out pretty well at 31 psi and WOW, that is real fun to drive, but WAY too much for the street... Even 25-27 is too much for the street (25 is the minimum starting point of boiling tires in 3rd gear) So i keep her around 22 or so which is right on the edge of traction in 3rd for most of my daily stuff.. The last free dyno pull day i went to I layed down 431/396 and was tuned as rich as you would on pump gas at like 11:1 (just because i hadn't finished the tune due to constantly changin parts out to increase air flow) Now i'm hoping that at 12:1 I can make a tad more, then the bottle is to ensure that on the rollers i can get a 500+ slip for bragging rights, and then i'll mainly use it for "insta-spool" in a race or as a "back up" if something starts pulling away from me

It's funny that when i was only making the 332/312 in my signature the quaiffe actually felt like it did a TON for traction in 1st and 2nd gears. But since i broke the 400 horse barrier it's lighting them both up like tere was never an LSD installed, leaving twin/equall length black marks and making smoke at any legal posted speed in my state with just a light rolling into wide open.... I can't even imagine if i was still on an open diff.. I'd probably run 14's at 130 MPH .... but now i got POSI BABY!!! and when i couple that with some fresh M&H slicks it should be a really intense ride then (for a FWD street car anyway) I know there's plenty of cars on here that are a lot faster, but mine is still a blast for me!

 

[oVaBoost]

I always do mine at like 95 ftlbs and then after 1500 miles I retorque them to 100 never had a problem.

 

[90rslaser]

so i just reassembled my motor with the cometic hg and arp studs with the moly. what exactly are the heat cycles and retorquing specs. start the car, let it run for 5 minutes, turn off, retorque? how exactly am i supposed to do it? and how many times? srry, not trying to hijack the thread, but just needed some helpful info since you guys were already on the same sort of track

 

[e85_4g63]

I have the standard ARP's (not the L19's). I int. torque them to 81 lb. ft. then after 2K miles I set the wrench to 84 lb. ft. I doubt the oil would wash the moly off completely though. Also, as a side note, I DO NOT use any moly lube on the threads that go into the block, just the tops where the actual ARP nut threads on. I've never had an issue with any of the ARP/ Mitsu MLS setup's I've torqued (then retorqued) to 81/84 respectively.

 

[PLYMOUTH TURBO]

Did a couple heat cycles on my freshly rebuilt head and wanted to know the correct procedure on what to do when I retorque my arp head studs, is there a special procedure I have to do,thanks

 

[donniekak]

Take a torque wrench set for whatever you torqued them to and make sure they haven't come loose. You don't want to loosen and tighten them that defeats the purpose of the heat cycles.

 

[Mitsu RacerX]

Torque them down the way you torque them down beforethe heat cycle. You should get a lil turn but not much if any..

 

[NHerron]

I reference MOLY LUBE with all the examples given:

This is old, yeah. But I recently talked to ARP several times about torquing in general. One reason for the 'steps' in torquing, besides having an even clamp load across the component, is to overcome STATIC friction. Example (ft lbs): 30-60-80. But if you later want to recheck the torque after a few heat cycles say with 80-85 ft lbs on the wrench, it won't do you any good. BECAUSE the fastener is already set at 80 ft lbs -it will take more torque INITIALLY to get the fastener moving again. (Like initial current draw from started motor to get rotating assembly to move, during cranking)

With static friction in mind, NEVER let your torque wrench go until it clicks! While torquing, if you start to come CLOSE to the intended value (say 80 ft lbs) and you let the pressure off the wrench -to ratchet back for more swinging room- you will notice the wrench will click right away after that. If this were to happen (just to get the idea) torque values could differ +/- 10 ft lbs between each fastener!

To the OP's question, this will sound funny but hang in there! Don't use 120ft lbs. Don't use 80ft lbs. Simply unbolt ONE FASTENER AT A TIME, reapply moly, and retorque to 80ft lbs. Reason being, is that the head gasket is what loosens things up. After you torque the bolts the first time, everything is pretty close to 80ft lbs. Now throw in a few heat cycles, TIME, and the constant strain on the HG and you get a drop from 80 to say 75 ft lbs torque. Now, people with OHC heads that block access to head bolts will do it a little differently to avoid all the hassle of removing cams. They torque everything down to final torque and LEAVE it for 12+ hours. Then come back, loosen up, retorque fasteners and continue with setting in the cams.

Also, when this is done: Make sure engine is completely cold, as in sitting for AT LEAST a few hours. DO NOT loosen all head bolts at once otherwise the timing belt pulling down can upset head gasket positioning and sealing quality and also interfere with the REAL torque being applied. So loosen the fasteners one at a time, reapply molt, and torque straight to 80 ft lbs.

If you got the time and ambitious enough, take off the timing belt and loosen all fasteners so you don't have to worry about the head gasket shifting and go in to correct torque sequence with the 3 steps.

The ultra torque lube sold today is actually really good at getting an even set torque the FIRST time and the 10th time. So no need to pre-torque UNLESS SPECIFIED BY ARP. Otherwise, coat everything with moly ultra torque and torque away those bolts one time. The theory of torque being more accurate after many times of torqueing holds true, especially with standard 30 weight oil, but not so much with the new advanced lube such as APR ultra torque moly lube. It certainly won't hurt anything but can you imagine torquing-loosening-torquing-loosening..etc, on a set of V8 heads?!

I hope this helps someone, and please correct anything explicitly wrong here, I don't want spread wrong schuttttuff here.

 

[ulitka]

I asked ARP tech support on how to properly re-torque the head studs/nuts. The key is to loose a nut about 45degs and torque it back to spec. Re-torque one nut at the time (follow the pattern documented in the service manual).

I do not think there is any need to remove nuts to apply ARP moly on threads of the studs/nuts/washer. There is no way oil will wash the moly lube off the studs/nuts threads which are torqued down to 80ft/lbs.

 

[josh1095]

i asked my machinist who just built mine. he looked up the arp specs and said with the moly lube 85lbs. he said i most def did not need to retorque them but i could for peace of mind. i did. not one budged a mm. after nearly 200 miles. the first 50 was the motoman breakin. im not pushing any coolant, burning any oil, or any other abnormalities. also using cometic mls hg.

 

[turboglenn]

i asked my machinist who just built mine. he looked up the arp specs and said with the moly lube 85lbs. he said i most def did not need to retorque them but i could for peace of mind. i did. not one budged a mm. after nearly 200 miles. the first 50 was the motoman breakin. im not pushing any coolant, burning any oil, or any other abnormalities. also using cometic mls hg.

motoman break in FTMFW!!!!!!! break em in easy if they're for your grandma, if a real driver's gonna own it seat it like it's gonna be driven

I retorque mine to 80-85psi now days when i am servicing things in the area of the head.

 

[josh1095]

glenn, i had to look that up: FTMFW hahahaha. yeah, ya know what? it sure as hell seated the rings quick. i can tell it has great compression without testing yet. its pull 21 at idle and runs very strong compared to other stock gst's ive riden in.

 

[TSIfreek]

I asked ARP tech support on how to properly re-torque the head studs/nuts. The key is to loose a nut about 45degs and torque it back to spec. Re-torque one nut at the time (follow the pattern documented in the service manual).

I do not think there is any need to remove nuts to apply ARP moly on threads of the studs/nuts/washer. There is no way oil will wash the moly lube off the studs/nuts threads which are torqued down to 80ft/lbs.

 

[JBDdsmer610]

i always torque mine to 100 ft lbs and use a torque to angle gauge...runs for a few hundred miles then torque to 100 again never had any problems.

 

[Josh97eclipse]

I did mine at 80 then after a few heat cycles went to 110