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Engine Specific Info and Questions => IDI Engine => Topic started by: pyro7890 on February 05, 2011, 11:13:27 am
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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)
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How did the stud fail? Did it break, twist off, pull the threads out of the block, etc?
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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.
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I think 100 ft-lbs on a 12mm stud is okay but if you had 11mm that probably was too hard on it.
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an 81 rabbit engine would be 11mm..
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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?
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I did 110 ft/lbs on mine on my 1.6td. No issues here.
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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
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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.
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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(http://forums.turbobricks.com/images/smilies/ignore.gif)
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As importiant as it is to lube the threads, its even more so you lube under the nut also.
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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....
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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
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I think I just blew a head gasket because copper coat and perma-torque do not play well together.
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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?
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It's the stuff Fel-Pro makes their gaskets with.
I burned off a lot of water, and still had over a gallon in the crankcase.
Is this coolant still good? ::)
(http://i18.photobucket.com/albums/b126/SVOlvo/DVC01145.jpg)
It failed right where 6.2s always do, but reading up on it, that seemed to be one of the things to avoid, and Fel-Pro does say 'Install Dry'
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for what coolant cost i wouldn't use it
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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....
copper and aluminum have a bad reaction.. really bad corrosion..
i know im not using any copper spray on my aluminum headed engines..
my grandpa swears by silver floral paint.. and so do i. have used it before with great results..
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I have done and re done many HG on different stuff. I have never had a bad fel pro, but I never used any coating on them. I feel there coating works or has for me.
On my last VW in my build thread I used ARP torqued to 100ft/lbs, permatex aviation sealant on both sides of the MLS gasket, and have no issues yet 11,000 miles.
I would also say the ARP IIRC have the 12-1.75 on the block end for threads, but the head end is 12-1.25 and that to is way finer than stock. Unless raceware does super fine 1.0 thread pitch if they can do that I would think they are the same.
I say you have a bad heat treat on the stud. At the tensile strength these have, eventhough chromoly is more forgiving than carbon or stainless alloys, it should break at about the same point it stretches. If the heat treat didn't get in there far enough instead of the high ultimate tensile strength it will be more elastic and stretch sooner. It is just a guess, but for what ARP charges for this stuff they should stand behind it either way.
Something else I did with my head studs was put on an old whipped gasket and torque/retorque several times at 80ft/lbs. Since my studs were new I wanted to relieve the stress in them if possible. ARP tells you to do it with there rod bolts and all the circle track cars that we built would suck until we started hanging them for 2 years after welding them up. I went overboard/full retard on mine though as it was the first diesel I did and first daily driver. I didn't want to run into trouble so I went the extra on every step.
Good luck getting the oil out of your coolant system. I think Maxfax has a procedure down pat if you need help contact him :D
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I was mostly just surprised it wasn't all mixed together.
My block deck was eroded, so I put in another one.
I might take that one to the machine shop and see what they say, aside form the leak, that 6.2 was one of the cleanest diesels I've ever seen inside.