Heat Riser Removal

[Lunchbox]

What’s the best way to remove the heat riser from an 340 exhaust manifold? Currently it is seized closed can wiggle it slightly.

 

[Katfish]

Soak with PB Blaster and heat cycle it with a torch.
I cut mine out and tapped it for a bolts.
Not for the original guys, but my car is just a driver.

 

[Lunchbox]

Soak with PB Blaster and heat cycle it with a torch.
I cut mine out and tapped it for a bolts.
Not for the original guys, but my car is just a driver.

Worked like a charm! Had a hose clamp I put around the large diameter counterweight, allowed me to get a larger channel lock on it without messing it up. PB, heat, work it, repeat. Moves freely now.

Looking at the butterfly it appears to be welded to the shaft on the inside of the manifold. Thus the reason to cut it to remove it.

Is it safe to assume this isn’t needed for fair weather cars? Would like to remove the butterfly but still make it look stock on the outside.

 

[Katfish]

Yeah, that's probably what I should have done.
With a little patience, you should be able to cut away the butterfly and leave the shaft intact.