ARP head studs

[timupdike]

I am installing a set of BB-3 Xtra on a BBC BOWTIE block. I purchased ARP head studs part # ARP 235-4702. Bolt holes are clean and have been chased. None of the studs will not seat all the way down. I called ARP the tech said it should be fine. Run it are not???

[amc fan]

I had a problem years ago with B&B main studs. You could screw a nut all The way up and down ,but when you threaded them in the block they would go in so far and lock up tight. They sent me new ones and I sent the old ones back.I am guessing something wrong with the thread chaser/roller and pitch got streched,not enough when you used a nut but it would not screw in the block.

[BillK]

I am installing a set of BB-3 Xtra on a BBC BOWTIE block. I purchased ARP head studs part # ARP 235-4702. Bolt holes are clean and have been chased. None of the studs will not seat all the way down. I called ARP the tech said it should be fine. Run it are not???

I would have to try a different set of studs before making a decision. If the threads are not correct the force might not be applied to all of the threads when you tighten it.

[FC-Pilot]

Are they bottoming out in the bolt holes? Have had to use a bottoming tap to get the threads run further down in the holes before. Also have bull nosed the end of the stud that screws into the block to get it to thread down into the block enough. Might want to contact the manufacturer and verify what should be done.

Paul

[6.50camaro]

Are they bottoming out in the bolt holes? Have had to use a bottoming tap to get the threads run further down in the holes before. Also have bull nosed the end of the stud that screws into the block to get it to thread down into the block enough. Might want to contact the manufacturer and verify what should be done.

Paul

That was my first thought also . I have also had studs in holes that weren't blind that were close to the cylinder walls on the water jacket side bottom out on the cylinder wall because the normal head bolt only went 2 or 3 threads thru the deck and not 6 or 7 theads like the studs I had . Looking down the bolt hole with a light I could see a few threads on the cut into the edge off the cylinder wall but not enough to fully seat the stud. I figured it was from a litte core shift . Dan

[af2]

The holes are blind. You need to put a ball bearing in the hole then the stud has the correct stopping point.

[Walter R. Malik]

I remember following the directions perfectly for the use of big block Chevy head studs from ARP.
It would pull the threads out of the block when torquing to what they wanted.
That torque was correct to stretch the stud the right amount but, with absolutely no regard for the material that the stud went into.

I hope they have changed their recommendations for that.

[FC-Pilot]

The holes are blind. You need to put a ball bearing in the hole then the stud has the correct stopping point.

That is why I would bull-nose the block end of the stud. That way it could properly “bottom out” in the blind head bolt hole without getting jammed in the incomplete threads near the bottom of the hole. I have had a few blocks where the threading did not go near deep enough, so I used a bottoming tap to finish the threads and then did not have to do either of these two goofy tricks. I prefer not to use the tap if I don’t have to.

I have had a few times where without the bottoming tap or bull-nose trick, the top of the threads sticking through the head ran out of threading for the nut before placing any torque on the head. I like it because it also ensures the most amount of thread engagement. Just my opinion though. Lots of ways to skin this cat.

Paul

[BillK]

None of the studs will seat all the way down.

Is it because they are bottoming out or because something is wrong with the threads on the studs ?? I had some main studs (not ARP) a while back that were just plain cut wrong. The thread pitch was off just enough that when you started threading them into the block they would go about 3/4 of the way and just stop turning It drove me crazy till I figured out what the deal was. I got a set of ARP studs and they were fine.

Try putting one of your studs into a different block and see what happens.

If they are just bottoming out then they should be ok.

[digger]

And if they don’t bottom out but have enough engagement then it doesn’t matter either unless they stick up too high or the nuts bottom out on the unthreaded part

[curtis reed]

Easy enough to have a shop run a thread ring gage on the threads of the stud to rule out thread pitch issues as someone stated they had.