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Spitfire Spitfire Headbolt Problem

JKB1957

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I went to torque the head on my rebuilt engine. Ten of the eleven nuts were fine, the last one actually spun the bolt out of the head. Even when I was able to get everything tight the bolt actually wobbled. The engine is for an 1147cc from a Spitfire MK2. I suspect that I will need to pull the engine and have a helicoil insert done by a machine shop, but maybe there are other ways to fix this problem. So any suggestions?
 
Are you saying that the bolt just stripped right out of the threads in the block, or that the bolt broke?

I worry about some of those bolt holes that are so deep.

If the threads in the block are gone, I'd be curious how deep that bolt hole is with the head removed?

What I've been told that even a shallow hole may require a machine shop to be certain you're getting that helicoil in straight. Naturally, that bolt needs to have a precise alignment.

On my car I got lucky. A bolt broke, but it was very near the top of the block, and I removed it with an "easy out." You can imagine my relief.

Good luck on yours, and please give us more facts.
 
I don't think he broke one off. I think he was more curious if it would eventually break if he reused a bolt.


<span style="font-size: 23pt"> <span style="color: #CC0000">EDIT</span></span>

OOPS I just pulled a Paul 161 and answered this in the wrong thread somehow.This was suppose to be the answer to Kens 941 Rod Bolt question

Dang ,hate when that happens
 
No, didn't break the bolt off. The bolts are new ARP studs. I went out after my first post and tried to tighten the stud. Now it just turns freely. I think when the machine shop chased the threads they goofed, because right now the threads appear to be missing.
 
Let us know what you find out. If they goofed up, maybe a HeliCoil would work, but I wonder about the spacing around the stud. Wouldn't that leave a gap?

Did you have the block out and to a machine shop already?

What else did they do other than chase the threads? It makes me wonder if there has already been work in that stud boring.
 
Took the engine apart today and will take the block down to a machine shop Thursday. Hopefully they will be able to insert a helicoil and I'll be good to go. We'll see.
 
Something to think about when putting the engine back together. Back in the day racers used wheel nuts in place of the regular head nuts. The wheel nuts are a lot meatier and will take the torque much better. Bob
 
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