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Ok I there anything I can do I had a brand new set of ARP head bolt snap on me during my second pass I have already tried bolt extractors with no luck. Yes the treads were chased and blown out qith air. Is there anything strong enough to drill this out and maybe install a timesert I have the kit but the bit is not strong enough to drill through the metal
If you can find some left handed drill bits, they will grab and usually walk the broken bolt right out. Hopefully you haven't tightened it to much trying to drill it the normal way. It should not have been tight at all. Would have walked right out with left handed bits.
I had to order a left hand drill bit for a broken rocker arm bolt that snapped, check with a Industrial supply house in your area. Place like this should have them. https://michigandrill.com/catalog/
Here's a video that a buddy of mine sent me, around 4:20 is where he starts.
McMaster-Carr. Be to your house in no more than 2 days. Usually the next day.
A carbide bit will not drill an ARP bolt. It would have to be cobalt. But I would not drill it out like that. It will get hotter than hell and your drilling in aluminum. Left handed bits will only take a few revolutions before it bites and walks the bolt out. Works fantastic. If your worried about shavings, put some grease on the bit and it will collect it all.
I've removed a lot of broken bolts welding a nut on there like the video. Works good. Just wouldn't do it where they did for the obvious reason that you can see, he fucked up the rocker stand.
Did you use the ARP lube on them? (Just curious... )
+1 on the left handed bit, it needs to be about 2/3 the diameter of the bolt your trying to remove.
If you drill down through the bolt and it doesn't rotate out, use a can of Cold Shot from a electronics supplier and spray it in the hole,
Wear PPE it can spray all over.. its cold enough to frost bite. The cold will shrink the bolt and let it spin out.
Then use a bit 1 size up and redrill the hole again. If you have it dialed in eventually you get to a bit that barely fits through the threaded hole, then a tap will clean the remaining metal out of the threads, go slow go easy speed is not your friend. You usually do not have to drill the threads out and thread sert if your careful.
Did you use a flat bottom thread chaser or tap to chase the threads and did it bottom out? if not the bolt probably wedged in the bottom of the hole.
You didn't get bolts that were too long? Head bolts shouldn't bottom out.
Good advice here on getting the broken stud out. Shouldn’t be a problem with the right tools. My question is…where did you purchase the ARP kit from, and was it new? Lots of fake sets out there coming from across the pond. The fake sets show up in cases like this where there was a fastener failure under normal torquing numbers, and usually bought at a discounted price. Might not be the case here, just curious.
As mentioned in my earlier post it can be done, you might want to try welding a washer one size smaller than the bolt diameter or stud to extract. If the bolt or stud had bottomed out then the weld method probably would be best. Then weld a nut to the washer, the washer acts as a barrier to protect the surface. Let cool then try to remove. Try again if it fails the first time.
I started to drill out the bolt with a left hand drill near the center and tried to put the just right amount of pressure & drill speed with the tip greased. Keep a magnet handy to occasionally pickup the metal filings. After not much depth penetrated I took a new set of punches and a awl and tried to counterclockwise rotate the bolt out. Sharpied a line at 6:00 on the broken bolt and rocker boss. Then started to angle tap the bolt near the outer parts of the broken bolt with a short ball peen hammer . It started to move a bit. Boy was I happy!
I then replace all the rocker arm bolts with the BTR 12 pt. ones that came in the kit, torquing to 22 lbs slowly to avert another catastrophe.
Started to rotate and come out.
Pieces I had on hand before I started.
Jackpot! it felt like I had won the lottery since these are brand new LS3 heads.
Last edited by cula8r; 09-21-2021 at 07:53 PM.
Reason: added something
Welcome to ARP quality. I had 2 head bolts break in 2 different sets, back to back on my sons engine. Both under 65 lbs-ft.
But since the bolts never bottom out, they will thread right out. Especially if you used the thread lube like you're supposed to.
Also I have been building and machining engines for many years. Lets just say I have a good payout in scrap weight from broken fasteners of all brands. Strongest bolts I ever seen was Caterpillar and Donovan.
Don't over think it. They usually come out pretty easily.
09-17-2021, 08:38 PM
Arp stud snap in Iron block 
