word to the wise do not over torque your arp studs - page 1 - IDI Engine - VWDiesel.net The IDI, TDI, and mTDI source.

• word to the wise do not over torque your arp studs by pyro7890 on 05 Feb, 2011 11:13
• i have a 81 rabbit 1.6 na and i bought studs to remedy the problem of the block cracking. i was having problems with a coolant leak and everyone told me just up you torque, up your torque(i used arp ultra torque which is also very important) so i got them up around 100 ft lbs which is 20 over what arp says and it stretched on of my studs rendering it to be a failed stud email arp and they said dont that since i over torqued it they would not replace it.
  
  now the story may be different if you do not use arp ultra torque because the ultra torque makes it so you only have to do two torque sequences
  (obviously a tourqe after first warm up)  
• #1 by RustyCaddy on 05 Feb, 2011 11:59
• How did the stud fail?  Did it break, twist off, pull the threads out of the block, etc?
• #2 by Quantum TD on 05 Feb, 2011 14:51
• Well, this has always been my problem with A) the VW torque sequence, and B) Aftermarket Stud torque values. The aftermarket manufacturers aren't explicit about the % difference in torque values.
  
  If you use simple oil on the studs, then you can torque like the factory guidelines, and finish about what they finish at (100-120 ftlbs).
  
  Compound this with an absolutely stupid torque procedure provided by the manufacturer for the head. I'm really at a loss as to why the Germans, who are so anal retentive about everything, outline a torque procedure that is so imprecise. There are so many factors that will affect toque values, so why would you make it even more imprecise by having so many steps.
• #3 by rabbitman on 05 Feb, 2011 16:01
• I think 100 ft-lbs on a 12mm stud is okay but if you had 11mm that probably was too hard on it.
• #4 by R.O.R-2.0 on 05 Feb, 2011 16:13
• an 81 rabbit engine would be 11mm..
• #5 by RustyCaddy on 05 Feb, 2011 16:37
• Quote from: rabbitman on 05 Feb, 2011 16:01

  I think 100 ft-lbs on a 12mm stud is okay but if you had 11mm that probably was too hard on it.
  

  
  i have 11mm ARP studs at 100 ft/lbs and retighten them every couple of months lately when i start getting pressure in the coolant expansion tank...loosen them a 1/4 turn but then go about 1/2 turn to get back to 100 ft/lbs...stretching?
• #6 by kaneb on 05 Feb, 2011 18:02
• I did 110 ft/lbs on mine on my 1.6td.  No issues here.
• #7 by pyro7890 on 05 Feb, 2011 20:01
• i wish i could say the same for mine. i will try to get a picture on here but it probably wont happen. it stretched is what it did. your 1.6 td has 12 mm studs so they could take more torque. the biggest problem was the ultra torque if i would have used oil 100 ft lbs probably would'nt have been enough
• #8 by RustyCaddy on 05 Feb, 2011 20:21
• Oh...you said right off it had stretched it at the beginning of the thread...my dumb.
  
  it is hard to understand these things.  ARP and Race Ware are basically the same grade steel with the same pitch thread...ARP has 80 ft/lbs with ultra torque, or around 115 with 10w/30 oil but Race Ware is only 50 ft/lbs with 20W/50.
  
  Maybe ARP sent a stud that was substandard in the lot you got....that said the head comes off of mine next time after what happened to you.
  
  Sorry that happened to you about that.
• #9 by 745 turbogreasel on 06 Feb, 2011 01:09
• I'm pretty sure my Raceware are way finer pitch than stock, and will crush the head if you go to 100.
  They also warn against extra slippy lube.
  Now I leak fuel instead of boost
• #10 by sdwarf36 on 06 Feb, 2011 05:20
• As importiant as it is to lube the threads, its even more so you lube under the nut also.
• #11 by arb on 11 Feb, 2011 22:06
• You know ? For the past 30 years, every time I read something like this I think - wouldn't the use of Peratex Copper head gasket spray on our head gasket solve this problem like it does on a small block  Chevy ?  Have not tried it yet....
• #12 by truckinwagen on 11 Feb, 2011 22:12
• the last headgasket I did I used permatex aviation sealer which worked great.
  
  previous to that I used the copper spray on a MLS and had no issues.
  
  some say they have to be dry, but I dunno...
  
  -Owen
• #13 by 745 turbogreasel on 11 Feb, 2011 23:57
• I think I just blew a head gasket because copper coat and perma-torque  do not play well together.
• #14 by rabbitman on 12 Feb, 2011 00:33
• Quote from: 745 turbogreasel on 11 Feb, 2011 23:57

  I think I just blew a head gasket because copper coat and perma-torque  do not play well together.

  
  What's perma-torque and how did it react with the copper coat?