LT1 Based Engine Tech 1993-1997 LT1/LT4 Engine Related

help.. helicoil spinning, how can I fix?

Thread Tools
 
Search this Thread
 
Old 11-20-2004, 01:38 PM
  #1  
Registered User
Thread Starter
 
Paul94Z's Avatar
 
Join Date: Jan 2000
Location: Ocean Springs, MS
Posts: 222
help.. helicoil spinning, how can I fix?

I'm hoping to get some good ideas on how I should go about fixing one of the helicoils in my head that wont hold the correct torque when I tighten down the intake. I've though of increasing the bolt/helicoil size or maybe using some jbweld and a new helicoil? what are my options? what would you do?
Paul94Z is offline  
Old 11-20-2004, 02:09 PM
  #2  
Registered User
 
Spinner's Avatar
 
Join Date: Jul 2003
Location: Fort Benning, GA
Posts: 2,947
Re: help.. helicoil spinning, how can I fix?

Just put in a new one.
Spinner is offline  
Old 11-20-2004, 02:23 PM
  #3  
Registered User
Thread Starter
 
Paul94Z's Avatar
 
Join Date: Jan 2000
Location: Ocean Springs, MS
Posts: 222
Re: help.. helicoil spinning, how can I fix?

I tried that last time I had the intake off.. still wouldn't hold full torque
Paul94Z is offline  
Old 11-20-2004, 04:19 PM
  #4  
Registered User
 
buelldevil's Avatar
 
Join Date: Nov 2002
Location: Pensacola, Fl
Posts: 117
Re: help.. helicoil spinning, how can I fix?

Try some locktite.
buelldevil is offline  
Old 11-21-2004, 08:17 AM
  #5  
Registered User
 
OldSStroker's Avatar
 
Join Date: Oct 2002
Location: Upstate NY
Posts: 2,931
Re: help.. helicoil spinning, how can I fix?

Originally Posted by Paul94Z
I'm hoping to get some good ideas on how I should go about fixing one of the helicoils in my head that wont hold the correct torque when I tighten down the intake. I've though of increasing the bolt/helicoil size or maybe using some jbweld and a new helicoil? what are my options? what would you do?
It sounds like the Helicoil tapped hole is oversize, or there is too much of the aluminum stripped out. You could go to the next larger standard thread size, but you might have to open up the hole in the manifold. I don't remember if the bolts ar 5/16 or 3/8. If they are 3/8 you could go to 10mm (about .015 in. larger), and put in a 10 mm Helicoil. You'd have one bastard bolt, but it wouldn't be much out of place.

Another option is a key-locking threaded insert. Try looking up this item in McMaster-Carr catalog: 93340A420

http://www.mcmaster.com/

This might be your best bet. Look back one page for the description.

Welding up the hole and remachining it is a real chore.

I'd stay away form the jbweld, etc.
OldSStroker is offline  
Old 11-21-2004, 09:29 AM
  #6  
Registered User
 
arnie's Avatar
 
Join Date: Oct 2001
Location: smog zone adjacent to a great lake
Posts: 1,462
Re: help.. helicoil spinning, how can I fix?

Going to a 10 mm thread (X 1.5) from a 3/8" X 16 tpi. would probably accomplish the dilemna of the O.D. slop in the hole (the extra 64th could do wonders) but a small amount of thread shaving, on one side of the thread (cross threading), caused from going to the 16.9 tpi. from the 16 tpi., would be experienced in addition to the 'major dia.' increase, but minor, and that option very workable, nonetheless. I agree, it's a good idea. How 'bout locking in a stud, in that location, as an option?

Last edited by arnie; 11-21-2004 at 09:58 AM.
arnie is offline  
Old 11-21-2004, 10:15 AM
  #7  
Registered User
 
drop top steve's Avatar
 
Join Date: Aug 2000
Location: Portland, OR
Posts: 504
Re: help.. helicoil spinning, how can I fix?

Look at this part # on mcmasters web site.
90240A003
I have used these with great resluts on holes that the helicoil threads have been pulled, leaving an over size hole.
drop top steve is offline  
Old 11-21-2004, 12:43 PM
  #8  
Registered User
Thread Starter
 
Paul94Z's Avatar
 
Join Date: Jan 2000
Location: Ocean Springs, MS
Posts: 222
Re: help.. helicoil spinning, how can I fix?

90240A003 looks interesting.. but damn $113 for the driver tool?! I found another key locking insert that has a 3/8-16 with a 9/16-12 external dia size.. what should I get? any way around that driver tool?
Paul94Z is offline  
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
ryanhilsgen
Drivetrain
9
09-21-2015 07:34 PM
GusarskiSS
Exhaust System
1
09-02-2015 03:51 PM
FredM
LT1 Based Engine Tech
1
08-14-2015 01:49 PM
jackpawt883
LT1 Based Engine Tech
8
07-31-2015 08:15 AM
Boss002
Autocross and Road Racing Technique
2
07-24-2015 10:47 AM



Quick Reply: help.. helicoil spinning, how can I fix?



All times are GMT -5. The time now is 12:23 AM.