bolts snapped off in exhaust manifold

[wazooz2424]

when separating my exhaust manifold from the intake manifold on my inline 250, 2 of the bolts snapped off inside the exhaust manifold. any ideas? should i drill them out or just replace the exhaust manifold? any idea where i can find a manifold, besides a junk yard? thanks

[shifty]

good luck getting them out. i've broken more bolt extraction bits removing frozen bolts from rusty manifolds than i care to remember. i hear using a torch to heat up the bolt is a good way to aid in the extraction.

i bet some of the old timers around here have some good feedback.

[Fred T]

I've successfully removed more than my share. Start by mounting the manifold securely in a vise. If there is any bolt shank protruding, grind it square. Then take a center punch and mark as close to the center as you can. Drill for an easy-out. You need to heat the area and let it cool several times. Also apply Kroil or PBlaster when cool. Sometimes paraffin will seep into the threads. Then heat the manifold flange until it's orange and try the easy-out. Like Shifty said, it's easy to break them, so don't get too hamhanded.

If that doesn't work, finish drilling the bolt out. Iirc, it's a 5/16-18 thread. Tap drill size is F, but since you don't have an F drill, use a 1/4" as the final size. Next step will be to run a tap into the hole, which is why it's important to hit the center.

You can buy new studs at the hardware or parts store.

[Fred T]

The old mechanics (pre-70s) had their own way. With the manifold in the vehicle take a cutting torch and blast a hole through the broken stud. While the iron is still soft, drive the new stud into the hole with a hammer.

I was never that good with a torch. But it worked, and was fast. But when your getting paid book rate, you did what you had to to maximize your paycheck.

[wazooz2424]

i was looking at this more and it appears that the bolts were actually part of the exhaust manifold and went through holes in the intake manifold and were tightened together with nuts?????? does this sound right, or is it possible that there is so much rust it just appears to be all one piece?

thanks for the help so far.

[shifty]

If they were holding the intake/exhaust together, i can't recall, but you may be correct. Have you simply tried pounding the little buggers out?