318 Heat riser rattle/tapping

[cogaussie]

I have a 72 Barracuda 318. The heat riser on the exhaust manifold has consistent rattling, I am under the understanding that it should go away once the engine heats up to optimum. Mine seems to keep going, its rather embarrassing. I heard you can weld/tap it open or you can remove the riser completely.

What is the best option / easiest and can someone guide me through.

thanks

jc

 

[moparleo]

The best thing would be to repair it. It helps keep the fuel atomized when the car is not up to running temperature. In other words, its job is to channel the exhuast back through the intake manifold under the carburetor to warm the fuel up until the car warms up then it opens to allow maximum exhaust flow. If it rattles, the thermal spring is probably broken and needs replaced. It is a lot easier to repair with the manifold on the work bench. Not expensive but depending on corrosion, tools available to you it can take a while.

 

[Chryco Psycho]

SO you are in OZ where the coldest temp you ever see in winter is what 70* ??
I would remove the plate

 

[moparleo]

Chryco is right if you are not interested in keeping it all stock.

 

[Chryco Psycho]

it can still look stock , you can leave the shaft & spring in place

 

[cogaussie]

Gets to about 32 at the lowest maybe a little lower. I am not really keen on taking off the manifold to take out the plate.. would rather wire it open or tack weld it open, not sure if the cast iron will take to the weld though.

 

[moparleo]

For safety, you should remove the manifold if you plan on trying to weld cast iron. Brazing can be done easily as brass melts at a lot lower temp than cast iron and will provide a very strong bond if done properly. Also cast iron requires preheating before attempting to weld and if you don't have experience welding cast iron you will probably ruin your manifold.

 

[cogaussie]

Clockwise or counter clockwise?? Open or closed?

For safety, you should remove the manifold if you plan on trying to weld cast iron. Brazing can be done easily as brass melts at a lot lower temp than cast iron and will provide a very strong bond if done properly. Also cast iron requires preheating before attempting to weld and if you don't have experience welding cast iron you will probably ruin your manifold.

I want to wire it open, is it counter clockwise CLOSED and clockwise OPEN?

thanks

 

[burdar]

There is a steel bushing that's pressed into the manifold. You can easily weld the shaft to that bushing.