Other: Broken Bolt Removal from Cylinder Head

[jhicban]

For anyone out there that is battling a broken bolt/stud in a cylinder head... Here is what worked for me.

1. Removed the cylinder head in order to work on the bench to ensure I was drilling perfectly straight.
2. Used spring loaded center punch to help start the drill bit off straight and true.
3. Used left handed threaded bits to drill out the broken bolt (hoping that eventually it may catch and back itself out... it didn't). Lots of cutting oil, and compressed air to remove metal shavings as I drilled more and more.
4. Progressively went from smallest drill bit to 5/16 (bolt size is 3/8 - 16).
5. Used a 3/8 size bit to partially drill out the upper most top section of the bolt hole (no more than 1/4 inch deep) . This gave me a guide to re-tap the bolt hole perfectly straight.

Thank you for everyone who has chimed in on the previous threads (Popcorn Popping Sound Coming from Passenger Side of the Engine
and 55 Commander - Head Removal) offering advice on how to tackle this dilemma.

I hope this helps someone else down the road.

J

[jackb]

I have performed this exact procedure and it worked for me perfectly...patience!

[Studejohnn]

Well done. Good approach, and you got the result you wanted. I've done it slightly different with good results. After drilling out to 5/16, insert a reverse bolt extractor and see if what remains ofthestuck threads back out. Get good depth onthedrilled hole and use the CORRECT size extractor the size of the drilled hole. This way you might avoid having to put a drill bit close to the threads. Heli-coil might also save the day if it really goes wrong.