Broken Exhaust manifold stud

[Denis]

My brother called me yesterday. He has an old Power Wagon with a 251 flathead engine. While removing the exhaust manifold to make a repair, 3 of the 7/16" studs broke off flush with the block. We would appreciate any ideas on getting these studs out. The best solution so far is drilling and trying an "E-Z" out. If that does work keep drilling to size and retap. Only problem here is centering the drill bit on the stud and drilling with the engine still in the truck.

 

[Joe Mc]

Denis,



Old hot wrencher's trick # 243a. Goes like this: weld a flat washer to what's left of the stud (fill hole inside of washer with weld to the stud remnant), then weld a nut to the washer (inside the nut and a few places on the outside to the washer). Now that the old stud has been heated up by all this welding shoot some penetraiting oil at the threads and get an impact on the nut. Zap it right out! If it doesn't work try it again and heat area around the stud with a torch try again.



Worked for me on 8 broken studes on an old 440.



Joe Mc

 

[AKAMAC]

If you can get a set of reverse (LH) drill bits this could be very easy.



file flat any stud sticking out of block, center punch the stud and use an 1/8" drill bit to start the pilot hole, use a map gas torch to heat up the head, then use LH bit to remove stud.

Be sure to only go 3/4" in head. The thread depth is normally 7/8".

Good luck!