Stripped a head bold, WTF now?
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Pro
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From: Aliso Viejo CA
Stripped a head bold, WTF now?
Ok, so on my bro's 71 454 that we are building, one of the last bolts we were torquing gave way and stripped completely.
What's the best way to fix it? We are building a 550-ish hp engine. Nothing extreme. 10-1 comp...
drill it and use helicoils? Will those hold? It was one of the center ones toward the end of the head if it matters...
[Modified by Warlock, 11:40 PM 4/12/2002]
What's the best way to fix it? We are building a 550-ish hp engine. Nothing extreme. 10-1 comp...
drill it and use helicoils? Will those hold? It was one of the center ones toward the end of the head if it matters...
[Modified by Warlock, 11:40 PM 4/12/2002]
Safety Car
Joined: Jun 2001
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From: Severna Park Md
Re: Stripped a head bold, WTF now? (Warlock)
Pull the head and run a tap in all the threads. Check other headbolts for inperfections. If the bolt was the damaged item then you might get lucky and just need a new bolt. If all precautions were taken prior to assembly, its extreemly rare to have a head bolt strip off. It possibly may have bottomed out on gunk left in the hole before it was to its torqued spec. Excessive force placed on the bolt in this situation could cause stripping and or breakage of the bolt.
Melting Slicks
Joined: Aug 1999
Posts: 2,848
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From: Atlanta, Ga, Fulton
Re: Stripped a head bold, WTF now? (Jvette73)
You bet it is possible. I had Pontiac rocker arms in Chevy P/N boxes direct from TRW. Dopes had the correct Chevy nuts and ***** in the box with Pontiac rocker arms. Check EVERYTHING trust NOTHING to be correct these days.
Sometimes you can just get a longer head bolt if the threads are OK down deep in the hole. Buddy did that with a 455 pontiaac engine. Not sure what you did to the 454 so you might be out of luck.
Sometimes you can just get a longer head bolt if the threads are OK down deep in the hole. Buddy did that with a 455 pontiaac engine. Not sure what you did to the 454 so you might be out of luck.
Le Mans Master
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From: delmont pa
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Re: Stripped a head bold, WTF now? (Warlock)
heli coil will work fine. cover and tape off the top of the engine with a piece of cardboard to keep out the chips and work away. i would use some type of fixture to make sure that you drill and tap the hole straight. use a drill bit with a negative angle on the tip to prevent the drill from grabing in the cast iron. :chevy
Moderator
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From: Dove Mountain Arizona
Re: Stripped a head bold, WTF now? (Warlock)
I've done this before (helicoil that is) and my suggestion is to put a pencil magnet in one of the water jacket holes. Get it close to the hole you're working on on the bottom side. This will pick up most errant metal chips so they don't stay in your cooling system. Just pull it out a few times to clean off the chips. :cool:
Drifting
Joined: Jul 2001
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Re: Stripped a head bold, WTF now? (Warlock)
The big Chevy uses two tad bit shorter bolts on the upper row at each end.When you remove the head,lay them all out and you will note the difference.Have though seen the ARP's all equal lenght before.These must have a thick washer put under them.Suggest a good threaded insert with a locking agent like the green locktite over a heli coil though and you might want to think about leaving the head on and using it as a drill guide,,,with grease smeared all around the hole to catch the shavings.
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Le Mans Master
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From: delmont pa
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Re: Stripped a head bold, WTF now? (mountainmotor)
the only problem i have seen with BB chevy head bolts is that after market bolts are longer to allow for head bolt washers and they will bottom out in the bottom row on the passenger side,the front 2 holes. i am aware that SB have 3 different length head bolts but never saw it on BB. :chevy
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Pro
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From: Aliso Viejo CA
Re: Stripped a head bold, WTF now? (clem zahrobsky)
With the Edelbrock RPM heads we used, the correct bolt kit has three different length bolts. Anyway, we used a small square to keep the drill at the right angle and repaired it with a helicoil. It torqued to spec, so it looks good. :cheers:
Thanks
Thanks
Drifting
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Re: Stripped a head bold, WTF now? (Warlock)
Something that I did not know until I actually read the ARP box. It says that you are not supposed to run tap through the head bolt holes. They have a special chaser for the head bolt holes. I have alway run a tap through them but I thought that was very interesting. I have had to use a heli-coil before on a 406 that I built. It has 11.1's and it has held up just fine.
