-
ARP studs; to retorque or not to retorque?
by
rayrayworldwide
on 12 Oct, 2007 13:47
-
OK. I've done thorough searches on this and other vw diesel sites and can not seem to get a solid answer to this question.
I have a rebuilt and machined head, ARP headstuds, and metal HG.
Do you need to retorque ARP headstuds? After running the engine warm the first time? Or, after 1000 miles?
ARP instructions that come with the studs says to torque to 80 ft/lb. And thats it! There website offers the technique mentioned in earlier posts of torqueing, loosening, and retorqueing 5 times to achieve proper tightening.
So, what have all you ARP headstud users done?
Why no mention of the retorque method on the instructions included with the studs.
-
#1
by
Audi80
on 12 Oct, 2007 14:05
-
No retorque
-
#2
by
rallydiesel
on 12 Oct, 2007 14:23
-
I would also like to know. I will not retorque until shown a reason to.
-
#3
by
Black Smokin' Diesel
on 12 Oct, 2007 16:40
-
Retorquing is for stretch bolts, when they stretch you have to retorque the bolts to compensate for the difference in lenght. I replaced the head on my TD, after 1000 miles it had a slight oil leak which fixed itself when I retorqued the bolts (OEM stuff).
-
#4
by
Wolfsbur
on 13 Oct, 2007 10:26
-
So far, I've never had to re-torque TTY headbolts.
ARP headstuds are undercut, so you don't need to re-torque.
Raceware headstuds (at least the sets I have from 10 years ago) need to be re-torqued after a full heat-up cycle-not under cut.
TTYs are indeed stretched, and when at the correct yield rate should not require any additional turning for their service life.
-
#5
by
subsonic
on 13 Oct, 2007 17:52
-
From what I remember about the ARP studs, as well as from talking to one of thier tech's is that they reccomend a stretch guage or the tighten / loosen method to get proper setting / fastening strength. The studs will stretch a bit on first and second torque sequence. The 3rd and final torque sequence should be the most accurate. All of this is dependent on the lube you use as well. If you do not use the ARP supplied, then the friction value increases. Increasing needed torque. If the stretch guage or multiple tighten loosen method is used, you should not have to re-torque. Stretch has already been achieved.
-
#6
by
stopping
on 13 Oct, 2007 18:10
-
I was told stretch bolts were invented to replace normal bolts to eliminate the re-torquing required at the dealership after 3000km or 15 cycles of full hot to full cold. I think you still need to run the engine to max temp and re-torque.
I might be mistaken but you should not have to re-torque if you follow the stretch bolt tightening sequence and (apparently) the right greese.
BTW what specifically is the grease they supply for the bolts?
-
#7
by
subsonic
on 13 Oct, 2007 19:00
-
BTW what specifically is the grease they supply for the bolts?
This has some info on it.
Also from my instruction directions:
"Use the manufactorers torque sequence but do not use the engine manufactorers torque specs. Torque the nuts to 80ft. lbs for ARP moly lube, or torque to 120ft. lbs with 30wt motor oil.
Do not use other moly lube. Use only ARP moly lube or head gasket failure may result"
http://www.arp-bolts.com/Catalog/Catalog.PDF/ARPCatalog_0086.pdf
-
#8
by
stopping
on 15 Oct, 2007 16:11
-
That makes sense. I have a question, in my interest, though when bentley wrote the manual and quoted torque specs what lube were they using?
I am not using ARP stretch bolts (yet) so I am following the typical sequence. 30-40-50ftlbs-90deg-hot-180deg.... I think that's how it goes.... so in the interest of those of us not lucky enough to be using stretch bolts..... I am wondering out loud what the best lube is to get the results of the Bentley. I have been using regular hydraulic grease, threads and btw head and washer. (how much air pressure do you think is in there every time?)
-
#9
by
zukgod1
on 15 Oct, 2007 17:48
-
That makes sense. I have a question, in my interest, though when bentley wrote the manual and quoted torque specs what lube were they using?
I am not using ARP stretch bolts (yet) so I am following the typical sequence. 30-40-50ftlbs-90deg-hot-180deg.... I think that's how it goes.... so in the interest of those of us not lucky enough to be using stretch bolts..... I am wondering out loud what the best lube is to get the results of the Bentley. I have been using regular hydraulic grease, threads and btw head and washer. (how much air pressure do you think is in there every time?)
ARP's are
not stretch bolt, that's the whole point....
Using ARP lube will work, I think it says something about 30w oil in the instruction (not sure dont have them right here).
-
#10
by
TPW
on 16 Oct, 2007 05:12
-
What happens if you use moly lube with stock stretch bolts?
-
#11
by
rabbit GTI/GTD
on 17 Oct, 2007 15:47
-
I'm in ontario canada, Where can i order ARP head studs from, and what application/part # do i order, thanx, for a 1.6TD
-
#12
by
Slave2School
on 17 Oct, 2007 16:14
-
summit racing, and Ford Cosworth (works in a AAZ and TDI, not sure about the 1.6TD)
-
#13
by
stopping
on 30 Oct, 2007 19:22
-
I thought you were talking about stretch bolts called ARP... never heard of em.
As usual folks hear are light years ahead of me!
what's the difference btwn ARP and regular (non-stretch) bolts.... besides not needing to re-torque?
-
#14
by
cowboybootlegger
on 30 Oct, 2007 22:45
-
I thought you were talking about stretch bolts called ARP... never heard of em.
ARP is a manufacturer of high performance bolts, studs, and other fastners. They offer dozens of kits for a wide range of engines, and everything from rod bolts and head studs to oil pump bolts. The difference is the bolt material and tensile strength (ARP's is ultra high). Alot of racers use them for high horspower and high boost applications.
In my '83 Rabbit 1.6TD I have a set of ARP head studs formulated for the Ford Cosworth (as mentioned above, they just happen to be the same thread pitch and length, and there are 10 in a set, so it works out)
I've actually installed and removed the head 3 times since i put them in, using stock 3 notch head gaskets every time, thank God i wasn't buying bolts every time, those studs almost paid for themselves already (i had an obstruction in #2 intake valve chamber, couldn't figure out why i wasn't making compression, took 3 installs to figure it out, it's a long story :oops: )
The first install I used ARP's moly lube, and only did 80 ft/lbs torque,
but i noticed a fairly immediate coolant system pressurization, beyond what is normal, and as i was driving the last 5 miles of an 800 mile trip to Albuquerque NM, i blew up a brand new expansion tank bottle, (couldn't have been the 23psi of boost for a mile while racing a cummins truck, ; ) luckily i packed a spare) and so i replaced the head gasket, and torqued those little buggers to 130ft/lbs, using 15w-40 oil (all i had in my grandpa's driveway) It's worked great ever since, and i hit 25psi regularly. 
:twisted:
I do install the studs in the 4 torque stages, something like 25, 55, 120, 130. Then i go over them again just for good measure. I don't like leaks. :wink: From my experience, I'm not sure a retorque is necessary.