Are the three bolts holding the heat riser in place supposed to come out once the nuts are removed? I took the nuts off of mine but the bolts/studs ain't moving. Can't see crap in there my work light is dead. Also I'm assuming once the bolts are removed the heat riser can then be tooken out? Or do I need to remove the entire exhaust manifold? The car is a 63 chevy impala.
The studs don't need to come out. The heat riser should slide down off of the studs. If it is rusted a few taps may get it off. If not it may need heat and heavy persuasion.
Bit of a pain getting a good exhaust seal if you remove it. Better off to cut the butterfly out and weld up the shaft holes if you're dead set on getting rid of the heat riser.
The heat riser don't look like it would slide out as the exhaust pipe is below it. I'm trying to remove it so I can see what size i have on there (not sure if 2" or 2.5")to replace it with a heat riser delete plate.
^^^ Used to be able to buy the flanges. 1" thick, came in 2'' or 2 1/2" sizes. You have 2'' unless it's a 300 horse or bigger. I'd keep the heat riser in No. Cal. - that kind of weather you need it.
I've heard from some old timers it has very little if any significance. Idk, I'm kind of leaning toward getting rid of it. My car from the factory had a wee little 283 small block. It now has a 350 as it's had since I bought it years ago. I'm not 100% sure but I think the manifolds were from the original smaller block but I'm just guessing.
As has been suggested, just cut the heat riser shaft so the butterfly drops out. Then weld up the shaft holes if they weren't sealed when you cut the shaft. Done. You can also just wire the butterfly in the "open" position if you don't want to go to the trouble of dropping the exhaust on the right side. Not high tech but it works just as well and is easily reversed if you ever want to make the heat riser operational again.
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