Jump to content


Photo
- - - - -

Brand New Minispares Cylinder Head Bolt Just Sheared! How Do I Get It Out?


  • Please log in to reply
50 replies to this topic

#31 gazza82

gazza82

    Up Into Fourth

  • Members
  • PipPipPipPipPipPipPipPipPip
  • 2,902 posts
  • Location: Bucks
  • Local Club: TMF+

Posted 20 March 2017 - 09:22 AM

3/8 UNC according to Minispares website https://www.minispar...sic/CAM151.aspx

 

You should be able to fit these by hand .. if they bind, take it out, clean the thread and hole and try again. I think these are dry-fit too.


Edited by gazza82, 20 March 2017 - 09:24 AM.


#32 carbon

carbon

    Up Into Fourth

  • Members
  • PipPipPipPipPipPipPipPipPip
  • 2,590 posts
  • Location: UK

Posted 20 March 2017 - 09:22 PM

I would avoid using a tap to clean up the thread in the block if possible. Try first with a 3/8 UNC bolt, but use some moly grease on it (starter motor or clutch slave cylinder bolts are 3/8 UNC).



#33 Northernpower

Northernpower

    Mr. 7-Port

  • Members
  • PipPipPipPipPipPipPipPipPip
  • 2,409 posts
  • Name: Graham
  • Location: North Yorkshire (God's County)
  • Local Club: Its out there somewhere

Posted 20 March 2017 - 09:38 PM

I would avoid using a tap to clean up the thread in the block if possible. Try first with a 3/8 UNC bolt, but use some moly grease on it (starter motor or clutch slave cylinder bolts are 3/8 UNC).

Whats the reason for not using a tap to clean up the thread?

#34 carbon

carbon

    Up Into Fourth

  • Members
  • PipPipPipPipPipPipPipPipPip
  • 2,590 posts
  • Location: UK

Posted 20 March 2017 - 09:55 PM

I like to leave as much metal as possible on highly stressed areas.

 

Also a lot of the cheap taps and die sets don't have particularly good thread forms, which can leave stress raisers. Try running a cheap die down a head stud, and you can often see where it has cut into the root of the thread leaving a sharp edge.



#35 Abbot

Abbot

    Stage One Kit Fitted

  • Noobies
  • PipPipPip
  • 62 posts
  • Location: Croissy sur Seine

Posted 20 March 2017 - 10:09 PM

Bin there and got the tee shirt.

I failed to use an extractor properly and left a bit of the extractor buried in the stud.

My expert was not impressed but he did manage to weld something on to my flush stud and then wind it out.

For reference when you start again on the re assembly

  1. check your toque wrench is set correctly and preferably calibrated (reason for my 1st stud shear) 
  2. make sure your new studs are degreased and dry, petrol works well (reason for second failure to achieve torque)


#36 minimans

minimans

    Speeding Along Now

  • Members
  • PipPipPipPipPip
  • 411 posts
  • Location: Bay Area San Fransico

Posted 20 March 2017 - 11:42 PM

If your drilling  the stud unless your very very good (or lucky) you will incur some damage to the original thread in the block, it may well pay to fit a helicoil  to that location, you really don't want to pull the thread out of the block.



#37 mkw

mkw

    One Carb Or Two?

  • TMF+ Member
  • PipPipPipPipPipPipPip
  • 1,001 posts
  • Location: Sheffield

Posted 21 March 2017 - 09:58 AM

If your drilling  the stud unless your very very good (or lucky) you will incur some damage to the original thread in the block, it may well pay to fit a helicoil  to that location, you really don't want to pull the thread out of the block.


I think this is the key to be honest, once I get the old stud out I'll buy a kit.

#38 Carlos W

Carlos W

    Mine is purple, but I have been told that's normal

  • TMF+ Member
  • PipPipPipPipPipPipPipPipPipPipPip
  • 10,110 posts
  • Location: Sittingbourne, Kent

Posted 21 March 2017 - 10:45 AM

Have you contacted the company?



#39 mkw

mkw

    One Carb Or Two?

  • TMF+ Member
  • PipPipPipPipPipPipPip
  • 1,001 posts
  • Location: Sheffield

Posted 21 March 2017 - 10:49 AM

Have you contacted the company?


Minispares? Yes, I sent them an email Sunday through their website but haven't had a response.

#40 Northernpower

Northernpower

    Mr. 7-Port

  • Members
  • PipPipPipPipPipPipPipPipPip
  • 2,409 posts
  • Name: Graham
  • Location: North Yorkshire (God's County)
  • Local Club: Its out there somewhere

Posted 21 March 2017 - 10:51 AM

 

Have you contacted the company?


Minispares? Yes, I sent them an email Sunday through their website but haven't had a response.

 

Simon is an active member on here, if you don't hear back quite soon I would suggest you contact him direct.


Edited by Northernpower, 21 March 2017 - 12:22 PM.


#41 nollyd

nollyd

    Super Mini Mad

  • Members
  • PipPipPipPipPipPip
  • 663 posts

Posted 21 March 2017 - 11:33 AM

Is there a small machine shop near you.i work in one in and it would be a simple job but im too far away or i would sort it for you.they would set it up on centre of the stud and accurately redrill it.be careful with the weld as it distorts stuff like mad.good luck with it.

#42 whistler

whistler

    Camshaft & Stage Two Head

  • TMF+ Member
  • PipPipPipPipPipPipPipPip
  • 1,699 posts
  • Location: Cardiff

Posted 21 March 2017 - 11:42 AM

 

Bin there and got the tee shirt.

I failed to use an extractor properly and left a bit of the extractor buried in the stud.

My expert was not impressed but he did manage to weld something on to my flush stud and then wind it out.

For reference when you start again on the re assembly

  1. check your toque wrench is set correctly and preferably calibrated (reason for my 1st stud shear) 
  2. make sure your new studs are degreased and dry, petrol works well (reason for second failure to achieve torque)

 

I am not an Engineer so I just ask from a DIY point of view......why do you degrease and insert dry studs?



#43 nollyd

nollyd

    Super Mini Mad

  • Members
  • PipPipPipPipPipPip
  • 663 posts

Posted 21 March 2017 - 11:51 AM

Diy point of view is take your time.you could try applying a little heat as cast iron will expand quicker than the steel bolt will.just an idea.

#44 tiger99

tiger99

    Crazy About Mini's

  • Members
  • PipPipPipPipPipPipPipPipPipPip
  • 8,584 posts
  • Location: Hemel Hempstead

Posted 22 March 2017 - 02:54 PM

The reason for degreasing and inserting dry studs is that the stud will be stressed correctly when it is torqued up, not grossly overdone as it might be with some fancy lubricant, or underdone. The threads need to be properly tight so they all share the load, cast iron not being nearly as strong as the HT stud. And yes, they should be torqued up, not just finger tight. It is easy to do with the double nut technique. Just do not exceed 30 lb ft as you tighten the two nuts (3/8" UNF ie head huts) back to back, and use the torque wrench on the top nut to get 20 lb ft between stud and block. Then the load will be distributed reasonably well between stud and block.

#45 whistler

whistler

    Camshaft & Stage Two Head

  • TMF+ Member
  • PipPipPipPipPipPipPipPip
  • 1,699 posts
  • Location: Cardiff

Posted 22 March 2017 - 04:28 PM

The reason for degreasing and inserting dry studs is that the stud will be stressed correctly when it is torqued up, not grossly overdone as it might be with some fancy lubricant, or underdone. The threads need to be properly tight so they all share the load, cast iron not being nearly as strong as the HT stud. And yes, they should be torqued up, not just finger tight. It is easy to do with the double nut technique. Just do not exceed 30 lb ft as you tighten the two nuts (3/8" UNF ie head huts) back to back, and use the torque wrench on the top nut to get 20 lb ft between stud and block. Then the load will be distributed reasonably well between stud and block.

Thanks for the answer. The rest I do as you describe anyway.






0 user(s) are reading this topic

0 members, 0 guests, 0 anonymous users