Head bolts broke through?

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NHscamp

NHscamp

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I just installed my 360 indy/IMM heads with the ARP bolts supplied by Brian . I used the mr g 1121 gasket . No decking of the block or heads. I used the arp lube that came with the bolts and toured in three steps. I was on the 100ft pounds ( and in the final turns) and felt like a couple of the bolts broke through they were tight then a little slack then down to tourque. I read threads on here about using thread sealers on them but I checked all holes and the were blind and opted to follow the arp directions and used there lube on the threads. My question is can I take out the bolts and add tread sealer to them and retourqe? Or is everything junk and I have to start over?
Thanks Chris
 
I think disassembly and inspection is in order. Is that 100 LB FT with aluminum heads? At any rate, no way to know without tearing it back apart.
 
No they are cast iron. Is this common? Have you heard of it happening before?
 
No. That's why I recommended disassembly. What difference does it make whether anyone has heard of it? You've got a problem and you need to see what it is.
 
The blind bolt holes are usually drilled deeper than they are threaded. Unless someone has bottom tapped them, then you should not have broke through, but maybe just bottomed out on the thread and the hole is a bit deeper...


I agree with RRR, tear it down and look into it.
 
Did you clean the bolt holes before you assembled the engine? Could be trash in the bolt holes.
 
Does not sound good to me. Any disclaimer on the Indy site about what bolts or STUDS to use? Hope for the best.
 
67cudafb said:
Did you clean the bolt holes before you assembled the engine? Could be trash in the bolt holes.
Click to expand...
Agreed !!!
Tapping and cleaning before torque is the only way to get a true torque reading !!!
 
NHscamp said:
I just installed my 360 indy/IMM heads with the ARP bolts supplied by Brian . I used the mr g 1121 gasket . No decking of the block or heads. I used the arp lube that came with the bolts and toured in three steps. I was on the 100ft pounds ( and in the final turns) and felt like a couple of the bolts broke through they were tight then a little slack then down to tourque. I read threads on here about using thread sealers on them but I checked all holes and the were blind and opted to follow the arp directions and used there lube on the threads. My question is can I take out the bolts and add tread sealer to them and retourqe? Or is everything junk and I have to start over?
Thanks Chris
Click to expand...

When torqueing head bolts with washers, you will sometimes get a bolt almost to TQ, and then it frees up just a bit and then torques...this is usually due to no lube between the head of the bolt and washer and lube between the washer and the head itself...so the friction from the washer and bolt momentarily fee up and then back to tight...it happens.
If you feel better you can remove and inspect but I don't think it's possible to break into the block with our ARP bolts...they are only about .500-.600 out of the head deck when installed and most blocks have a min. of .750 deep holes.
 
I thought you broke a bolt...Did not read your post correctly...
 
Thank you gentlemen for your time, I had "surgically " cleaned and tapped all holes, and used the arp lube on threads and washers as directed. I have been scratching my head over this all afternoon when my son came in and was admiring my tourqe wrench and says hey you know this socket has a crack in it". Sure enough there was a small split in the socket so I believe/hoping it was just spreading and slipping at full tourque. I will investigate further and let you know if I find anything different.
 
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