Repairing stripped headbolt threads in the block (B series)
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Repairing stripped headbolt threads in the block (B series)
Disclaimer: I am not a machinist. The Ideas here are just to help. There maybe other and better ways to do this. I have had great success doing this in these steps. I have tried to give as much detail as possible, so hopefully you can take from this to draw your own conclusions on doing the repair. please no flaming. IMO this is a ONE SHOT DEAL. THREAD REPAIR CAN ONLY BE DONE ONCE THIS WAY. This is a fairly easy repair, just time consuming. Attention to detail is key to success in doing this repair.
The kit. Some of the parts are modified and others will not be used. The 30mm sleeves have to be ordered seperate from the kit. The kit is availible from Wurth USA 1 800 987 8487. The inserts are 11mm (bolt diameter) 1.5mm pitch 30mm long.
On the right is the stock insert. I have ground off the lip with a dremel tool (the sleeve on the left) to allow this to be counter-sunk into the block. ** make sure the lip is completely gone and has a nice taper to it and the threads clear or it will not go all of the way into the block. If it stops short there may not be enough thread contact to ensure this repair will work**
optional view: NOTICE THE TAPER (shiny area)
Here, I have welded a 9mm deep socket 1/4 drive to the top of the tap. This will allow the tap to go down into the block. If there is a manufacturer who makes a tap with a longer shank, this will eliminate the need to do this welding modification.
Using a caliper, measure the maximum depth of the threads. it will be different from block to block.
Mark the tap to the desired depth with tape.
Before the tapping is done, I recommend taping off the entire block to ensure no shaving fall into the casting. (assembled block)
This is how I used the tap. At this point tap the block. I recomend using a sticky grease (Swepco 101 or another moly grease) on the tap to help remove the shavings and to cut easier. Run the tap into the block to the marked depth a couple of times to make sure the threads are clean. Then carb cleaner out the remaining grease and shavings.
I then marked the ARP headstud (factory bolts can be used) to the desired depth as well.
I then hand tighten the the insert onto the headstud. (there is a tool used to install the sleeves, but it too isn't long enough to reach into the block) I use the headstud to istall the sleeve into the block.
the sleeve will not go all of the way onto the stud. The last two coils are smaller than the others. When the sleeve is tightened all of the way, these last coils will expand locking the sleeve in place. Red thread lock can be used as well.
By tightening two of the nuts together, this will alow you to run the head stud all of the way until it stops snug. It is very important to make sure that the sleeve is installed all of the way, so it can lock in place. Constant measuring and attention to how deep the inserts go is critical. This should be near the marked depth. 1mm to 3mm difference in depth is acceptable.
remove the head stud (or bolt) to ensure that the sleeve has locked into place.
When using head studs, it is dificult to hand tighten the studs, so wrenching them into place is a must. Just make sure that all of the studs are in deep enough and equal in height.
[Modified by 2point6, 7:53 PM 7/5/2002]
The kit. Some of the parts are modified and others will not be used. The 30mm sleeves have to be ordered seperate from the kit. The kit is availible from Wurth USA 1 800 987 8487. The inserts are 11mm (bolt diameter) 1.5mm pitch 30mm long.
On the right is the stock insert. I have ground off the lip with a dremel tool (the sleeve on the left) to allow this to be counter-sunk into the block. ** make sure the lip is completely gone and has a nice taper to it and the threads clear or it will not go all of the way into the block. If it stops short there may not be enough thread contact to ensure this repair will work**
optional view: NOTICE THE TAPER (shiny area)
Here, I have welded a 9mm deep socket 1/4 drive to the top of the tap. This will allow the tap to go down into the block. If there is a manufacturer who makes a tap with a longer shank, this will eliminate the need to do this welding modification.
Using a caliper, measure the maximum depth of the threads. it will be different from block to block.
Mark the tap to the desired depth with tape.
Before the tapping is done, I recommend taping off the entire block to ensure no shaving fall into the casting. (assembled block)
This is how I used the tap. At this point tap the block. I recomend using a sticky grease (Swepco 101 or another moly grease) on the tap to help remove the shavings and to cut easier. Run the tap into the block to the marked depth a couple of times to make sure the threads are clean. Then carb cleaner out the remaining grease and shavings.
I then marked the ARP headstud (factory bolts can be used) to the desired depth as well.
I then hand tighten the the insert onto the headstud. (there is a tool used to install the sleeves, but it too isn't long enough to reach into the block) I use the headstud to istall the sleeve into the block.
the sleeve will not go all of the way onto the stud. The last two coils are smaller than the others. When the sleeve is tightened all of the way, these last coils will expand locking the sleeve in place. Red thread lock can be used as well.
By tightening two of the nuts together, this will alow you to run the head stud all of the way until it stops snug. It is very important to make sure that the sleeve is installed all of the way, so it can lock in place. Constant measuring and attention to how deep the inserts go is critical. This should be near the marked depth. 1mm to 3mm difference in depth is acceptable.
remove the head stud (or bolt) to ensure that the sleeve has locked into place.
When using head studs, it is dificult to hand tighten the studs, so wrenching them into place is a must. Just make sure that all of the studs are in deep enough and equal in height.
[Modified by 2point6, 7:53 PM 7/5/2002]
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Thread Starter
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From: Tucson, AZ, USA
Re: Repairing stripped headbolt threads in the block (BigMoose)
I will have it on my site soon. I am going to add a section just for this purpose.
Great Job Scott! 
Too Bad there is not a separate Tech Archive to put stuff like this in for posterity.
Regards,
BigMoose
Too Bad there is not a separate Tech Archive to put stuff like this in for posterity.
Regards,
BigMoose
Thread Starter
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From: Tucson, AZ, USA
Re: Repairing stripped headbolt threads in the block (aeolus)
little off the subject,what kind of sleeves are those???
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From: Tampa, FL
Re: Repairing stripped headbolt threads in the block (sgT)
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From: Tucson, AZ, USA
Re: Repairing stripped headbolt threads in the block (sgT)
My machinist has a tap for the timeserts which is about as long as your "modified"
one. neeed to find out where he got it from.
one. neeed to find out where he got it from.
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From: Tampa, FL
Re: Repairing stripped headbolt threads in the block (non-VTEC)
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Joined: May 2001
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From: Trinidad, W.I.
Re: Repairing stripped headbolt threads in the block (Honda4CX-R)
Would this be superior or similiar to helicoiling ? How would this hold up to boost or high CR all motor cylnder pressures ?
Very good stuff
X2
Very good stuff
X2
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From: so cali
Re: Repairing stripped headbolt threads in the block (X2BOARD)
Can the bolt be tightened and lossened over time such as reinstalling the head stud? Lets say ie, you have to pull the head off and replace the head gasket?