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Damaged BB Head Bolt Repair #1465219
07/09/13 11:03 AM
07/09/13 11:03 AM
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Berwyn, IL
challenger70 Offline OP
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I noticed I have a damaged headbolt thread (7/16-14) on my block between #2 & #4 cylinder. I chased the threads with a tap and cleaned em up the best I can. I believe they will hold the 65ft/lb's they need to. They are just not as "sharp" as the other threads and I have a new bolt with perfect threads. This bolt had come loose before damaging the head gasket (it is why I have the head off). Should I just 1)go ahead don't worry about it, 2)use some thread locker on that thread, or 3)??. Anyway to fix this myself(I do not have a welder), without taking it somewhere, as I do not want to tow the entire car somwhere or pull the engine. Any such thing as a mobile thread repair service?

Re: Damaged BB Head Bolt Repair [Re: challenger70] #1465220
07/09/13 11:39 AM
07/09/13 11:39 AM
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Lincoln Nebraska
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RapidRobert Offline
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I lube head bolt threads/under bolt head with 30wt eng oil then blow it off with shop air leaving a thin coating. I'd do that & torque it to 65 with the head off & if it all feels good then go ahead & go together & I think you'll be OK


live every 24 hour block of time like it's your last day on earth
Re: Damaged BB Head Bolt Repair [Re: RapidRobert] #1465221
07/09/13 11:46 AM
07/09/13 11:46 AM
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pittsburghracer Offline
"Little"John
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Did you try using a bottom tap? If not give that a try and then as a band-aid maybe you can use a stud on that hole till you get a chance to fix it right on the next rebuild. DON"T use a cheap imported tap or a borrowed one that has been used way to many times.


1970 Duster
Edelbrock headed 408
5.984@112.52
422 Indy headed small block
5.982@112.56 mph
9.42@138.27

Livin and lovin life one day at a time




Re: Damaged BB Head Bolt Repair [Re: pittsburghracer] #1465222
07/09/13 12:56 PM
07/09/13 12:56 PM
Joined: Jan 2003
Posts: 21,080
Niles , Ohio
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therocks Offline
oh wait.but hey.lets see.oh yeah.
therocks  Offline
oh wait.but hey.lets see.oh yeah.
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Niles , Ohio
Actually you want to use a thread chaser.Taps cut the TC just cleans up the thread.Then install head and torque to what you need.If it holds remove install head gasket and go.Must be aluminum heads for 65 Ft pounds.Thats what mine are with ARP lube.Rocky


Chrysler Firepower
Re: Damaged BB Head Bolt Repair [Re: therocks] #1465223
07/09/13 02:16 PM
07/09/13 02:16 PM
Joined: Mar 2003
Posts: 3,358
Berwyn, IL
challenger70 Offline OP
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Quote:

Actually you want to use a thread chaser.Taps cut the TC just cleans up the thread.Then install head and torque to what you need.If it holds remove install head gasket and go.Must be aluminum heads for 65 Ft pounds.Thats what mine are with ARP lube.Rocky




My FSM says tighten them all to 50ft/lb first, then 65ft/lb

Re: Damaged BB Head Bolt Repair [Re: challenger70] #1465224
07/09/13 03:56 PM
07/09/13 03:56 PM
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Posts: 43,244
Bend,OR USA
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Cab_Burge Offline
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Quote:

Quote:

Actually you want to use a thread chaser.Taps cut the TC just cleans up the thread.Then install head and torque to what you need.If it holds remove install head gasket and go.Must be aluminum heads for 65 Ft pounds.Thats what mine are with ARP lube.Rocky




My FSM says tighten them all to 50ft/lb first, then 65ft/lb


I do 25 or 30 lbs, then 50 lbs and finally 70 Ft. lbs with a very thin coating of 5W20 WT oil on the bolts and a tiny bit in the head holes OP, if you decide to try and torque the bad hole make sure and make a spacer that will fit over the bolt and be very near the same length as the real bolt will be with the head on the motor Stick a bolt in the head and measure the amount of threads sticking out the bottom of the head and the make your spacer I bought several torque plates years ago and all of them came with spacers, it wouldn't suprise me that they started off as 1/2 inch I.D. black pipe


Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)
Re: Damaged BB Head Bolt Repair [Re: Cab_Burge] #1465225
07/09/13 04:01 PM
07/09/13 04:01 PM
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dogdays Offline
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You could put a HeliCoil in it if it doesn't torque down. They will absolutely hold. That's the safest route. They're not cheap. Probably cost about the same amount to buy a kit as it would to have a machinist do it.
R.

Re: Damaged BB Head Bolt Repair [Re: dogdays] #1465226
07/09/13 06:05 PM
07/09/13 06:05 PM
Joined: Mar 2003
Posts: 3,358
Berwyn, IL
challenger70 Offline OP
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Quote:

You could put a HeliCoil in it if it doesn't torque down. They will absolutely hold. That's the safest route. They're not cheap. Probably cost about the same amount to buy a kit as it would to have a machinist do it.
R.




Is a HeliCoil something I can do myself? I am more concerned with that bolt losing torque over time due to the less than stellar thread condition (why I am considering using some kind of threadlocker) than the threads failing there is still a descent amount of thread for the bolt to grab, there just beat up a little.

Thanks for all the replies

Re: Damaged BB Head Bolt Repair [Re: challenger70] #1465227
07/09/13 06:12 PM
07/09/13 06:12 PM
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dogdays Offline
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If that's the case, clean the threads as suggested elsewhere and torque the doggone thing up. If properly torqued it won't come loose.
No thread locker needed.

R.

Re: Damaged BB Head Bolt Repair [Re: dogdays] #1465228
07/09/13 10:49 PM
07/09/13 10:49 PM
Joined: Aug 2003
Posts: 43,244
Bend,OR USA
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Cab_Burge Offline
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Quote:

If that's the case, clean the threads as suggested elsewhere and torque the doggone thing up. If properly torqued it won't come loose.
No thread locker needed.

R.




Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)
Re: Damaged BB Head Bolt Repair [Re: Cab_Burge] #1465229
07/09/13 11:35 PM
07/09/13 11:35 PM
Joined: Mar 2003
Posts: 3,358
Berwyn, IL
challenger70 Offline OP
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Quote:

Quote:

If that's the case, clean the threads as suggested elsewhere and torque the doggone thing up. If properly torqued it won't come loose.
No thread locker needed.

R.







The only thing that concerns me is that this very bolt came lose, and I have no idea why, could have been not properly torqued by the builder. Would locktite hurt anything other than making bolt removal more difficult in the future? The helicoil idea is tempting too. I don't want to do any unnecessary work but want it fixed right. Thanks for the input.

Re: Damaged BB Head Bolt Repair [Re: challenger70] #1465230
07/09/13 11:48 PM
07/09/13 11:48 PM
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pittsburghracer Offline
"Little"John
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If this is going to keep you awake at night do yourself a favor and measure the head bolt. Now measure the head and the depth of the hole. See if there is anyway that you can use a longer bolt OR STUD to see if you can get down deep enough to hit the good threads at the bottom. Like I said earlier when you start a new build one of the first steps that you do is to chase the threads and thread the hole the whole way down to the bottom. That way you get proper torque on the bolt instead of trying to tap the hole with the bolt. Maybe your builder skipped that step, maybe he didn't. This is why I build my own engine so there is no second guessing. I know its done right. To many shoemakers out there. If you need a longer bolt check Summites site and buy a single LONGER bolt for that hole.


1970 Duster
Edelbrock headed 408
5.984@112.52
422 Indy headed small block
5.982@112.56 mph
9.42@138.27

Livin and lovin life one day at a time




Re: Damaged BB Head Bolt Repair [Re: pittsburghracer] #1465231
07/10/13 05:57 AM
07/10/13 05:57 AM
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colorado
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a12superbee Offline
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I too would look at a longer bolt or stud if possible.
Helicoils are great but if you haven't done a few, it's easy for the whole project to go from bad to worse.
I use them at work often enough but avoid them when there are other options.


I can't afford this. mark
Re: Damaged BB Head Bolt Repair [Re: a12superbee] #1465232
07/10/13 10:21 AM
07/10/13 10:21 AM
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U.S.S.A.
JohnRR Offline
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I would put a stud in the hole and forget it, it sounds like putting in the helicoil is above your skill level and if you do it wrong you are only going to make things worse. the hole has to be drilled and tapped straight, thread locker on the threads may give you a false torque reading.

Either tow it to a shop that can handle it or get a stud and nut from ARP.

Re: Damaged BB Head Bolt Repair [Re: JohnRR] #1465233
07/10/13 11:26 AM
07/10/13 11:26 AM
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Posts: 3,358
Berwyn, IL
challenger70 Offline OP
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Quote:

I would put a stud in the hole and forget it, it sounds like putting in the helicoil is above your skill level and if you do it wrong you are only going to make things worse. the hole has to be drilled and tapped straight, thread locker on the threads may give you a false torque reading.

Either tow it to a shop that can handle it or get a stud and nut from ARP.




I am liking the stud idea the most, any idea how much "virgin" thread I would pick-up? Thanks

Re: Damaged BB Head Bolt Repair [Re: challenger70] #1465234
07/10/13 11:34 AM
07/10/13 11:34 AM
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JohnRR Offline
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Quote:

Quote:

I would put a stud in the hole and forget it, it sounds like putting in the helicoil is above your skill level and if you do it wrong you are only going to make things worse. the hole has to be drilled and tapped straight, thread locker on the threads may give you a false torque reading.

Either tow it to a shop that can handle it or get a stud and nut from ARP.




I am liking the stud idea the most, any idea how much "virgin" thread I would pick-up? Thanks




can you cut the block down thru the damaged hole and post a picture of it along with showing the amount of bolt engagement ??



Without knowing how much of the original thread got disturbed by running a tap in the hole that is going to be a little tough to even guess at .

I'll make your head spin a little more , putting in a stud that grabs more thread LOWER in the hole is going to distort the bore differently than whatever fastner was used when the bore was originally honed , assuming it was done wit ha torque plate , then add in any wear from the amount of time it was run wit hthat head bolt flopping around in the valvetrain.

Now that I think of it

Re: Damaged BB Head Bolt Repair [Re: JohnRR] #1465235
07/10/13 12:22 PM
07/10/13 12:22 PM
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pittsburghracer Offline
"Little"John
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We are not talking about a Pro-stock engine here guys. Fix the dog-gone thing and run it. Cheese and rice.


1970 Duster
Edelbrock headed 408
5.984@112.52
422 Indy headed small block
5.982@112.56 mph
9.42@138.27

Livin and lovin life one day at a time




Re: Damaged BB Head Bolt Repair [Re: pittsburghracer] #1465236
07/10/13 01:33 PM
07/10/13 01:33 PM
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U.S.S.A.
JohnRR Offline
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Quote:

We are not talking about a Pro-stock engine here guys. Fix the dog-gone thing and run it. Cheese and rice.




all i did was answer the question he asked ...


Re: Damaged BB Head Bolt Repair [Re: JohnRR] #1465237
07/10/13 01:41 PM
07/10/13 01:41 PM
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pittsburghracer Offline
"Little"John
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Quote:

Quote:

We are not talking about a Pro-stock engine here guys. Fix the dog-gone thing and run it. Cheese and rice.




all i did was answer the question he asked ...






Sorry John that wasn't really pointed toward you. It just that some guys get so book crazy on every little issue their cars never hit the road. I personally would NEVER use a helicoil on anything after working with keenserts in the mill. Helicoils would fail everytime we used them and this is why we started using keenserts. For what he is doing going deeper and using a stud would last forever. Destort a cylinder. To the guy that is worried about this come-on now.


1970 Duster
Edelbrock headed 408
5.984@112.52
422 Indy headed small block
5.982@112.56 mph
9.42@138.27

Livin and lovin life one day at a time




Re: Damaged BB Head Bolt Repair [Re: pittsburghracer] #1465238
07/10/13 03:09 PM
07/10/13 03:09 PM
Joined: Mar 2003
Posts: 3,358
Berwyn, IL
challenger70 Offline OP
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challenger70  Offline OP
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Berwyn, IL
Quote:

Quote:

Quote:

We are not talking about a Pro-stock engine here guys. Fix the dog-gone thing and run it. Cheese and rice.




all i did was answer the question he asked ...






Sorry John that wasn't really pointed toward you. It just that some guys get so book crazy on every little issue their cars never hit the road. I personally would NEVER use a helicoil on anything after working with keenserts in the mill. Helicoils would fail everytime we used them and this is why we started using keenserts. For what he is doing going deeper and using a stud would last forever. Destort a cylinder. To the guy that is worried about this come-on now.




I appreciate the opinions and your expertise

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