HP Exhaust Manifold Heat Riser.....to REMOVE it or just Leave it in? Any better flow benefits?

[62maxx]

Is it worth it to grind out the heat riser butterfly and leave the "frozen" shaft intact? I was going to try a dremel cutting disc hooked up to a high speed drill and try to remove just the butterfly flaps. This is the "frozen" position that it is in. It does not look to be easy. Any helpful comments are greatly appreciated!

Thank you in advance,
R/T

 

[qkcuda]

If you're going to leave the shaft in I would think it won't make much difference. I cut the whole shaft out and plugged both sides.

 

[Jerry Hall]

Why take it out they are easy enough to get unstuck. Ofcourse you will need the heat spring and the anti rattle spring to make it operational.

 

[R413]

It makes no difference in performance. I was racing a consistent 14.0 440 and removing that did zero for ET and mph.

 

[pnora]

If I had it on the bench I would remove it and plug the holes.

 

[Jam72]

Why take it out they are easy enough to get unstuck. Ofcourse you will need the heat spring and the anti rattle spring to make it operational.

I had a similar stuck valve in a replacement for my 72 Charger. With penetrating oil and banging on the shaft periodically for a couple of weeks I freed up the shafts and valve movement. Only problem the external spring and parts are toast. Either I find and replace them or remove the valve, shafts and plug the holes or maybe just weld the shafts in the open valve position.