Slipping head bolts... better solution?
#1
Guys,
This has happened on both engines though the first one came into spec and I got it done. I ended up breaking one bolt and replaced the set.
I’m torquing bolts down in five pound increments after 50 pounds... at this point hoping the washers would stop spinning but a couple just won’t cooperative.
Using ARP’s lube, I’ve brushed some under the bolt head at the shoulder and on the threads. Per ARP’s suggestion, I have sanded the bottoms of the washers and a flat plane with 80-grit in a straight pattern to rough up the surface to catch the spot face on the head. I still have a few that slip... I don’t want to break bolts, or worse, pull threads. Almost wishing I had bought studs but the heads came with the ARP bolt sets.
Post-corona this is becoming a real b itch. I am wore out.
Would appreciate some suggestions.
This has happened on both engines though the first one came into spec and I got it done. I ended up breaking one bolt and replaced the set.
I’m torquing bolts down in five pound increments after 50 pounds... at this point hoping the washers would stop spinning but a couple just won’t cooperative.
Using ARP’s lube, I’ve brushed some under the bolt head at the shoulder and on the threads. Per ARP’s suggestion, I have sanded the bottoms of the washers and a flat plane with 80-grit in a straight pattern to rough up the surface to catch the spot face on the head. I still have a few that slip... I don’t want to break bolts, or worse, pull threads. Almost wishing I had bought studs but the heads came with the ARP bolt sets.
Post-corona this is becoming a real b itch. I am wore out.
Would appreciate some suggestions.
#2
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Joined: Nov 2004
Posts: 14,067
Likes: 3,667
From: On A Dirt Floor
Are sure the bolts aren’t bottoming out ? 502 blocks have blind head bolt holes.
And 5lb increments sounds odd. Sometimes it can take that or more extra to get the bolt to move over what the actual torque is.
And 5lb increments sounds odd. Sometimes it can take that or more extra to get the bolt to move over what the actual torque is.
Last edited by SB; 03-18-2021 at 05:33 PM.
#3
The increments were to avoid slippage. But I get what you mean.
The ARP head bolts I have are the ones for the 502 block. With exception of the long outside bolts, they’re the same length as the factory bolts. The long bolts aren’t slipping.
The ARP head bolts I have are the ones for the 502 block. With exception of the long outside bolts, they’re the same length as the factory bolts. The long bolts aren’t slipping.
#5
I have everything at 65 pound now. I’ll leave it over night and then back everything out and start again tomorrow evening. I did the same with the first engine and it was okay.
I made sure everything was clean on the heads (no lube between washer and head). This has been a new problem for me.
I made sure everything was clean on the heads (no lube between washer and head). This has been a new problem for me.
#8
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Joined: Oct 2020
Posts: 267
Likes: 142
What is ARP calling for on their specs? Not sure, but since you have torgued the bolts once already to 65lbs and say you are gonna pull them and start over, you may wanna check stretch and see if they already have before re-torquing them.



