On my '66 L-22 250 there is a flapper on the exhaust manifold. I understand that it heats the floor of the intake manifold.
What I'm wondering is what happens when the spring is missing. Is it in the cold or hot position when the flapper is horizontal and unloaded? What are the symptoms when it's not operating? How do you replace the spring?
The flapper looks to be permanently installed, so how do you replace and pre-load the spring? I'm assuming it's a bi-metal spring that is like the thermostat on my HVAC at home.
Thanks for the education
