I picked up a nice 216 exh. and intake manifold set with a functioning heat riser and just got it back from the media blaster. I want to change the spring now so I have a new replacement. Now my question: Does the spring expand as it heats up? Then it should pull the flapper closed to reduce the warm air going to the intake under the carb. right? What position do I have the flapper in when I put the end of the new spring onto the pin? I think it should be in the 'flap open' so then as the spring warms up and expands it should rotate the flap to the closed position.
