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Fabrication 101 Everyone has to start somewhere and for some, theOFN might be that somewhere.


Fabrication 101 Everyone has to start somewhere and for some, theOFN might be that somewhere.

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  #21  
Old 10-28-2013, 12:24 PM
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entropy entropy is offline
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Quote:
Originally Posted by 2Xtreme View Post
Thanks for the link.
I'll definitely give that a read.

Thinking I need to chase the threads. Bolts in question have several rounds of anti-seize and torquing on them. Well, the holes do. Bolts are new.

What's the best way to clean out a blind hole? Thread chaser and air, I would imagine. Right?
Blow it out.
Rinse it with Brakecleen or Acetone.
Blow it out.
In cast iron run a bottom tap full depth.
In Steel or Aluminum use a light coating of thread cutting oil then run the Tap.
Blow it out.
Rinse it with acetone.
Blow it out.

In something like a main bolt or head bolt in aluminum (mission critical application) the bolt hole should never see a cutting tap rather the threads should be cleaned then chased with a lubricated Forming Tap then cleaned and the bolt should be replaced with a stud.

Just because the factory does things does not make them right, rather they are the lowest permissible cost.
In aluminum castings things like exhaust bolts, spark plugs, etc, the threads should have been inserted or Heli-coil'd when the part was originally made!
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  #22  
Old 10-29-2013, 02:55 PM
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Chasing Bolt holes- I had some threads in my block that needed to be chased, but it was a weird metric thread size that my tap set didn't have. I cut 4 grooves in the threads of a used head bolt, worked great to clean up the blind holes.

To elaborate on what E said, you don't want to remove any of the thread material when chasing threads. Bolts and taps come in different classes that determine the amount of engagement that the internal and external threads have. I 100% agree that anything aluminum needs to be helicoiled or inserted, especially if you'll be removing the bolts numerous times or while it is hot. I rebuild old bag machines that have heater bars housed in a cast(old style) or billet alum body. These bodies see quite a few heat cycles at a max temp of 400 deg. Some of the cast bodies were made with a steel thread insert and still bolt up fine, even though they are probably 30-40 years old. Without an insert, I've pulled the threads out of a new billet piece that was hot, the first time a bolt was removed.

Torquing- Another note: I'll place a drop of oil on the underside of the bolt head to prevent it from galling the contacting surface and giving a false reading.
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  #23  
Old 11-13-2013, 10:59 AM
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ill probably get blasted for saying this, but over the years my best torque wrench has been my hands and a focused mind. just tighten every bolt from the middle out with great care, making sure they are all the same tightness. it takes a long time, because i go over each bolt about 20 times in a pattern, but i havent broken a bolt yet. the only 3 bolts ive busted were with torque wrenches.
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  #24  
Old 11-13-2013, 01:55 PM
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Resinis at what point do you consider the fastener torqued enough? I am not one to judge, but I think you are asking for trouble using that method on anything critical like rods, mains, or heads.
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  #25  
Old 11-13-2013, 04:56 PM
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Originally Posted by TheBandit View Post
Resinis at what point do you consider the fastener torqued enough? I am not one to judge, but I think you are asking for trouble using that method on anything critical like rods, mains, or heads.
its a touch. it cant be explained... i have used torque wrenches before and had a higher rate of failure when i do when i just tighten them by what i know is tight.

like i said, i know its not standard practice or what anyone should recommend, but i think anyone that has wrenched on cars for a long time doesnt really need torque wrenches because they can tighten by feel.

hell, manufacturers sure dont use them!! they just smash everything down as hard as their air ratchets go, or at least it seems like it, but dont get me started with that...
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  #26  
Old 11-14-2013, 08:05 AM
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...hell, manufacturers sure dont use them!! they just smash everything down as hard as their air ratchets go, or at least it seems like it, but dont get me started with that...
Really??

I'm not the most experienced on this site, but this is news to me.
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  #27  
Old 11-14-2013, 08:16 AM
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FWIW, this:

Quote:
Originally Posted by entropy View Post
Blow it out.
Rinse it with Brakecleen or Acetone.
Blow it out.
In cast iron run a bottom tap full depth.
Blow it out.
and this worked...

Quote:
Originally Posted by PDANKracing View Post
Chasing Bolt holes- I had some threads in my block that needed to be chased, but it was a weird metric thread size that my tap set didn't have. I cut 4 grooves in the threads of a used head bolt, worked great to clean up the blind holes.
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  #28  
Old 11-14-2013, 09:04 AM
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Originally Posted by 2Xtreme View Post
Really??

I'm not the most experienced on this site, but this is news to me.
No, not really. They use air powered tools on the lines, but they're supposed to be calibrated to tighten to the correct torque. When I was going to college, several friends had co-op positions at GM where the calibration was part of their responsibility.

I've also seen video from engine assembly plants where special tooling is used to torque all the bolts on a cylinder head, set of main caps, etc. at the same time.
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  #29  
Old 11-14-2013, 10:16 AM
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No, not really....
LOL... I was being sarcastic
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  #30  
Old 11-14-2013, 10:33 AM
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Graham08 Graham08 is offline
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LOL... I was being sarcastic
I figured as much...after I clicked "submit reply".
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  #31  
Old 10-06-2017, 06:53 PM
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jimmygarison jimmygarison is offline
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When I was going to college, several friends had co-op positions at GM where the calibration was part of their responsibility. I'm not experienced to this site difficult for me.
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