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Engine Specific Info and Questions => IDI Engine => Topic started by: chrischris on August 14, 2008, 09:42:09 am
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Currently, I am attempting to install head studs on my engine. I have an 11mm head and a recently acquired 12mm block that I am using.
I am having a heck of a time finding the proper sized ARP head studs. I had a mix up with Summit Racing (they sent me Mitsubishi bolts in a VW marked box) and the new head bolts are way too long.
Can someone tell me the correct part number for 12mm undercut head studs?
Here is a picture of the studs included with 204-4702 and an 11mm head bolt. I was told that these studs, which are for the 1.8/2l 16 v gas engine will fit my engine but they are extremly long.
(http://i37.tinypic.com/2w6857d.jpg)
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Try looking in the FAQ there is a good thread there with part #'s
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I got these ARP studs:
251-4701 Ford Cosworth Sierra/Escort head stud kit
Worked great.
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I got these ARP studs:
251-4701 Ford Cosworth Sierra/Escort head stud kit
Worked great.
But they are normal 12 mm studs, not undercut. You should just drill the head out to 12 mm and use the above mentioned studs.
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frick! i ordered head studs from a vw/import specialty shop in my town. i hope i didn't get the wrong ones? or do you think they would have thought of it? They know what head/block i have. how do you know if you need 11mm or 12mm
is 12mm for hydraulic head and 11mm is for mechanical?
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what is your engine code?
all td blocks regardless of lifter style are 12mm
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phew thanks i got 12
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I used a 11mm head on my 12mm block also. I took the head to a machine shop and had them drill out each of the bolt holes to the 12mm size.
Here is a tip: slide the studs you buy through the head to test and make sure they fit BEFORE you put everything together. I made the mistake of not checking and got the cylinder head stuck on the studs. I had to get ugly with a hammer and a block of wood to get it unstuck.
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There always Raceware if your not comfotable with the ARP P/N and multi-torqing debacle
http://www.raceware-fasteners.com/index.htm
You can call them, and they'll know exasctly what you need.
Works good, lasts long time.
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There always Raceware if your not comfotable with the ARP P/N and multi-torqing debacle
What do you mean by "Multi-torquing" ?
I don't believe there is a need to do any more than one torque sequence on any head stud..
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Someone posted the procedure here once supplied by ARP, they recomend doing multiple torqing to 70 ftlbs, then loosening, then going back to 70 ftlbs again for a few more times, then a final torque to 80 ftlbs. The spec sheet has something like 20 steps to tighten a freakin fastener.
I know ARP is cheeper, but the toqueing specs are nuts.
Raceware uses some type of proprietary antifriction coating on their fasteners and recomends using dino oil only and torquing in three steps to 50 ftlbs.
And, when you call Raceware and tell them you have a VW diesel, they know exactly what fastener you need.
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interesting for sure.
I just locked mine down to 80ft lbs and drove the piss out of it..
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Someone posted the procedure here once supplied by ARP, they recomend doing multiple torqing to 70 ftlbs, then loosening, then going back to 70 ftlbs again for a few more times, then a final torque to 80 ftlbs. The spec sheet has something like 20 steps to tighten a freakin fastener.
I know ARP is cheeper, but the toqueing specs are nuts.
Raceware uses some type of proprietary antifriction coating on their fasteners and recomends using dino oil only and torquing in three steps to 50 ftlbs.
And, when you call Raceware and tell them you have a VW diesel, they know exactly what fastener you need.
Huh. I called ARP, told the tech (Thirty six seconds for a tech to be on the line, it was awesome. :D) what I was doing and which part # studs I had, and asked if there was anything special I needed to do to torque them down. He said "Nope. Just thread the studs into your block, slide the gasket on, slide the head on, dab your lube packet on the stud ends and in the nuts, and torque them like you torque your head bolts, to the spec your engine calls for."
Straightforward as anything.
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sounds scary to me. I would NOT want to torque the studs as the bentley says to do the stretch bolts. I think the ARP tech is not what it should be. I could be wrong, but when the torque to yeild bolts start "yeilding" it sounds bad...if you did that with a 8740 chromemoly stud I think the head or gasket would be screaming instead. Probably wouldn't be good on the blocks threads either, but I as I am not the expert I would be more inclined to listen to the raceware people.
Sorry for not being more helpful on where to find the undercut stud in the original post.
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Huh. I called ARP, told the tech (Thirty six seconds for a tech to be on the line, it was awesome. :D) what I was doing and which part # studs I had, and asked if there was anything special I needed to do to torque them down. He said "Nope. Just thread the studs into your block, slide the gasket on, slide the head on, dab your lube packet on the stud ends and in the nuts, and torque them like you torque your head bolts, to the spec your engine calls for."
Straightforward as anything.
Wow, thats the third different torqing procedure they have given out.
Makes you go Hummmm.
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sounds scary to me. I would NOT want to torque the studs as the bentley says to do the stretch bolts. I think the ARP tech is not what it should be. I could be wrong, but when the torque to yeild bolts start "yeilding" it sounds bad...if you did that with a 8740 chromemoly stud I think the head or gasket would be screaming instead. Probably wouldn't be good on the blocks threads either, but I as I am not the expert I would be more inclined to listen to the raceware people.
Sorry for not being more helpful on where to find the undercut stud in the original post.
Keep in mind I was using studs in a non torque-to-yield application, and said as much. That was part of my "what I'm doing with them" explanation.
Sorry, that was my fault for not including that here.
Basically, I said I had ARP # 204-4701 stud kit from a VW 8v that I'm putting in my 8v VW diesel, and "do I need to do anything special to torque them down, or do I just follow the 36-50-65 ft-lb torquing procedure in the book?"
I don't think my little arms would make it to the yield strength on a stud. My little 150 ft-lbs torque wrench certainly wouldn't! :D
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am i missing something here ???????
on my brothers 1.6 td in his samuria we used arp studs ( the ones marked ford cosworth )
and in the instructions included it said to torque them to 130 foot pounds , which we did in gradual steps . ( actually i had him take them up to 140 foot pounds , i forget why , but we had to take the head off after he torqued them the down the first time .....)
where are you guys getting 80 foot pounds from ?
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I just pulled out the installation instructions for my ARP Ford Cosworth Sierra/Escort Head Stud (251-4701). It says to torque the nuts to 80 ft. lbs. w/ ARP moly assembly lube and 120 ft. lbs. w/ 30wt motor oil.
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I don't think I would feel secure with only 50 ft. lbs holding my head on.
I torqued my ARP Ford Cosworth Sierra/Escort Head Studs to 30-50-65-80 ft lb increments.
Any head stud or and head bolt needs to be torqued down gradually to prevent the aluminum cylinder head from warping. That is what I thought "multi-torquing" meant anyway. Sometimes you can loosen and re-torque to break any friction that messes up the final torque value.
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When useing ARP or Raceware studs do you hand thread them in to the block and thats it or are the torqued?
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When useing ARP or Raceware studs do you hand thread them in to the block and thats it or are the torqued?
I hand-threaded the studs and torqued the nuts.
... that sounds painful!
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Clean the threads in the block with a tap or chaser, install the studs hand tight, torque the nuts down as ARP says to and then do a hot torque. A hot torque is done after the engine has been ran and heated up to normal driving temps, shut it off and let it cool down to around 140* and retorque one at a time (break it loose and retorque). I usually add about 10ftlbs of tq over what ARP suggests.
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I don't think I would feel secure with only 50 ft. lbs holding my head on.
I torqued my ARP Ford Cosworth Sierra/Escort Head Studs to 30-50-65-80 ft lb increments.
Any head stud or and head bolt needs to be torqued down gradually to prevent the aluminum cylinder head from warping. That is what I thought "multi-torquing" meant anyway. Sometimes you can loosen and re-torque to break any friction that messes up the final torque value.
"multi-torquing" is my word for tightening/loosining/retightening that was specified in one of the myriad of ARP torqueing procedures.
The raceware studs are torqued in 3 or 4 progressive stages too, with an optional retorque after cooldown from the first run. I have the sheet somewere if anyone is interested.
The Raceware studs and fasteners have a proprietary anti friction coating on them. People have overtorqued them thinking that 50 ftlbs wasn't enough too and warped heads and/or stripped the studs.
Torq value only loosly relates to clamping force. The Raceware studs need less torq to achieve the same clamping force that the ARP studs need (choose one) 70, 80, 90, 100, 110, 120, 130, 140 ftlbs to achieve.
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I just pulled out the installation instructions for my ARP Ford Cosworth Sierra/Escort Head Stud (251-4701). It says to torque the nuts to 80 ft. lbs. w/ ARP moly assembly lube and 120 ft. lbs. w/ 30wt motor oil.
That makes a lot of sense. There has been SO much speculation on this thread but i think this is the most feasible route to follow.
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Ok guys, I have the studs and I am going to get my head drilled to allow the larger 12mm studs.
Now I am faced with the problem of finding washers to fit the new 12mm bolt recess holes. I lost my old washers and my new arp washers are too large. I found a spare washer that fits in but seems a little too small.
Are tight fitting washers important?
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sounds scary to me. I would NOT want to torque the studs as the bentley says to do the stretch bolts. I think the ARP tech is not what it should be. I could be wrong, but when the torque to yeild bolts start "yeilding" it sounds bad...if you did that with a 8740 chromemoly stud I think the head or gasket would be screaming instead. Probably wouldn't be good on the blocks threads either, but I as I am not the expert I would be more inclined to listen to the raceware people.
Sorry for not being more helpful on where to find the undercut stud in the original post.
To shed some more light on this....
Provided the thread pitch is the same, 30ftlbs is 30ftlbs regardless of the material of the bolt or stud is made from.
Also, that is why studs are resuable. They do not exceed the yeild of the material therfore they do not stretch.
You are applying slightly more clamping force on a stud, when using a torque wrench at the same setting for a bolt. Some of the torque actually goes into twisting the bolt, where as in a stud you do not get that. (thats why you get the difference in values when using different lubes)
As for ARP and different torque values. When part numbers are called out from a different vehicle and you apply them to your vw, why would you expect to get a straight anwser?
Comparing apples to apples, if the thread pitch is the same on the arp vs the raceware. the torque values should be the same.
Best procedure i have seen for studs....bottom tap your block. clean the holes. screw in the stud to bottom. back out 1 revolution. install gasket and block. using 3 or 4 steps, torque the head. warm it up, let it cool a bit, and retorque.
Try to lift the head....(its the skinny pedal)
Im running ARP studs in a truck making over 700 rwhp....so i am a little biased.
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Ok guys, I have the studs and I am going to get my head drilled to allow the larger 12mm studs.
Now I am faced with the problem of finding washers to fit the new 12mm bolt recess holes. I lost my old washers and my new arp washers are too large. I found a spare washer that fits in but seems a little too small.
Are tight fitting washers important?
Not as important as the correct alloy.
Dont be subsituting grade 2 hardware in there..... :shock:
Phone call to arp is probably the correct approach.
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I guess to maybe shed some light to what I meant was....
The head bolts for the vw are torqued then torqued and then through the series of 1/4 turn and 1/2 turn and 1/4 turn then the 1,000 mile 1/4 turn ...... I don't have my bentley in front of me but just from my memory that is something like it, I might have an extra 1/4 turn in there but the point is.....
That is what the manufacturer calls for on their head bolts, to my knowledge there is no torque value for the head bolts. If there is let me know. If ARP or whoever says " just do what the manufacturer does for the head bolts " I think it would be too much. After the 1/2 turn I think things would start to get difficult and ugly. This is what I was thinking in my response earlier, no offense to anyone, but just the way I was thinking. The 8740 chromemoly wouldn't yeild and the aluminum head or head gasket probably would or the threads in the block might not like it.
Like everything else I am probably overthinking and wrong, but I hope I am a little more clear on what I meant earlier is that ARP probably shouldn't say just do what the stock bolts call for. Lucas
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I guess to maybe shed some light to what I meant was....
The head bolts for the vw are torqued then torqued and then through the series of 1/4 turn and 1/2 turn and 1/4 turn then the 1,000 mile 1/4 turn ...... I don't have my bentley in front of me but just from my memory that is something like it, I might have an extra 1/4 turn in there but the point is.....
That is what the manufacturer calls for on their head bolts, to my knowledge there is no torque value for the head bolts. If there is let me know. If ARP or whoever says " just do what the manufacturer does for the head bolts " I think it would be too much. After the 1/2 turn I think things would start to get difficult and ugly. This is what I was thinking in my response earlier, no offense to anyone, but just the way I was thinking. The 8740 chromemoly wouldn't yeild and the aluminum head or head gasket probably would or the threads in the block might not like it.
Like everything else I am probably overthinking and wrong, but I hope I am a little more clear on what I meant earlier is that ARP probably shouldn't say just do what the stock bolts call for. Lucas
Got ya.
Probably best to get a straight reasonable anwser from arp.
Actually, maybe i will sit down with a calculator tommrow and just figure it out. anybody have the thread pitch of the arp studs? are they the same as the block threads?
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My so called VW head bolts have a sholder before the captive washer. THis causes a problem as when you try to incert them, the washer hits the cam bearing cap,,,
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Like everything else I am probably overthinking and wrong, but I hope I am a little more clear on what I meant earlier is that ARP probably shouldn't say just do what the stock bolts call for. Lucas
Like I said, he didn't say that right off, I told him the factory procedure and he said to do that. In my case, I have a 1.5, so factory procedure was a three-step torque sequence, rather than extra quarter and half turns and warmups and cooldowns and retorques for stretch bolts.
Supposedly my headbolts were reusable, but I wasn't gonna use those crapped out old rusting things.
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Actually, maybe i will sit down with a calculator tommrow and just figure it out. anybody have the thread pitch of the arp studs? are they the same as the block threads?
The block end is 1.75 and the head end is 1.25
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I just received this back from ARP in responce to my question.
"Hi there Daniel the torque specs for kit # 251-4701 is going to be 80ft lbs using ARP moly lube or 120ft lbs using 30wt motor oil. As for the sequence you're going to use the manufactures sequence and for torque it will be in three equal steps to our recommended torque specs.
The studs will be going into the block hand tight with lube being applied to both ends of threads and on both sides of the washers.
Thanks
John"
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Comparing apples to apples, if the thread pitch is the same on the arp vs the raceware. the torque values should be the same.
Yes, if the friction of the threads and washer are the same. It is not, so you have different torque values between Raceware and ARP.
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one thing that i dont get... why put the moly lube on the block end threads??? surely it doesn't really matter? just use regular engine oil?
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Comparing apples to apples, if the thread pitch is the same on the arp vs the raceware. the torque values should be the same.
Yes, if the friction of the threads and washer are the same. It is not, so you have different torque values between Raceware and ARP.
surface finish maybe different between manufacturers.
I ordered a full ARP kit from headbolts.com. TOTAL was $390 shipped (mains studs, head studs, con rod bolts)