Intake manifold bolt removal

[MikeS]

The four bolts that attach the intake to exhaust manifold, all broken.  Plan to heat w/oxy/acetylene.  How much heat can intake take w/o damaging the casting.  Plan also to use candle wax and kroil. Thanks guys.

[Sniper]

It's cast iron.  You can get it red

[MikeS]

Thank you!

[47 dodge 1.5 ton]

 Recommend drilling those out if you are saving the manifold. Note: The bolt hole side walls are very thin, and brittle. Remember, you don’t need to split for removal, can do those four on a bench. 

Edited January 17, 2022 by 47 dodge 1.5 ton

[sidevalvepete]

Good advice above. Others probably have more wisdom to add. My first attempt at this was a fail.......bet a few others have done the same.

Good luck ?

[Young Ed]

If you have any sticking above the surface you can cut a slot and hopefully use the heat to get it lose and then remove with a screw driver

[Dodgeb4ya]

I have done a lot of these broken off 23"  intake manifold bolts.

They can be tough to get out whether drilling out, soaking for a day etc.

I have the best luck mig welding a nut to the broken off bolt.

Letting it sit a bit with acetone and thinner mix then un-screwing the  broken off bolt and welded nut.

Sometimes still the bolt won't come out so I use the blue tip to carefully heat the manifold in the area the bolt threads are to a orange color fairly quick....the bolt will come right out.