Arp stud snap in Iron block
https://michigandrill.com/catalog/
Here's a video that a buddy of mine sent me, around 4:20 is where he starts.
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.
+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.
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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; Sep 21, 2021 at 07:53 PM. Reason: added something
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.











