Exh manifold bolts

[Resto_1]

We all know old rusted exhaust manifold bolts can be a @$*^. These are on a '64 383. Wonder if anyone has tried remove them when the engine is hot? My reasoning is the head casting is hot and woud have expanded, maybe loosening its grip on the rusty manifold bolt. Wish I coud get to the with an impact, but the head is on the engine. Relly don't want to remove the head(s) to install the headers. No smart comments, just good thoughts, please. Thanks.

 

[toolmanmike]

We all know old rusted exhaust manifold bolts can be a @$*^. These are on a '64 383. Wonder if anyone has tried remove them when the engine is hot? My reasoning is the head casting is hot and woud have expanded, maybe loosening its grip on the rusty manifold bolt. Wish I coud get to the with an impact, but the head is on the engine. Relly don't want to remove the head(s) to install the headers. No smart comments, just good thoughts, please. Thanks.

They can be tough and you don't know the best method until something doesn't work and you twist a few off. I would run the engine to heat them up before I tried anything. May be spray them with Deep Creep or the like. Pull on the wrench or ratchet carefully and work it back and forth to brake it loose. Use finesse not force.

 

[Sam69sat]

Sprayed pb blaster (vile smelling stuff) everyday for several days on original 67 318 manifold bolts. Got them all out without breaking any. I wasn't too worried though since it was out of the car already.

 

[R413]

Wire brush the rust first, spray and soak, let it sit. They are 3/8" so they don't break off very easy

You,
can't remove the head until you get the manifold out of the way of the lower row of head bolts.

 

[Thunderdan]

PB Blaster works great as do a number of other good penetrating sprays, however I would first use a hand held propane torch and work over the very local areas where the bolts are stuck fast (stay aware from plug wires or anything flammable). Not red hot, but pretty warm, then douse with PB Blaster and let sit a few minutes. It'll smolder with the hot metal, but the heat/cold should suck the penetrant under the bolt heads and into the threads. Rinse and repeat a few times with this process and the bolt should come free.

 

[Don Frelier]

An induction heater is hard to beat.

 

[Don Frelier]

I would get a good fitting 6 point and I like to use a small breaker bar so you can feel what's happening.
(Nice to know the exact moment you snap it off) a 3/8" drive should be enough.

 

[Billccm]

I just bought a induction heater to do this job.