41 Buick Heat Risers, Which way is the heat off position?

[Guest Earl]

This may be kind of a dumb question, but I'm not sure which direction would shut the heat off on the heat riser. Would it be when the weight it towards the engine? Or when it's more or less in the upright position? The rear one is stuck and I need to get that one loosened up and then wire them both in the "heat off" position. I don't want to have to remove the manifold just yet, this fall I'll probably pull the engine for a rebuild, but figure I might as well get some use out of it this summer yet the way it is. Thanks now.

[Guest Straight eight]

Is this a dual carb job? IF so the rear carb also has a valve that opens allowing the back carb to feed the engine.

Cliff

[Joseph P. Indusi]

From all I have seen of these, the "heat off" or exhaust directly out to the exhaust pipe and muffler is when the weight on the shaft moves down due to gravity. This is when the manifold is hot and the spring on the other side of the valve shaft relaxes and allows the weight to drop. When cold, the spring is tighter and holds the valve in a position to direct some exhaust gases through the plenum under the carburetor of the intake manifold to improve cold running.

Joe, BCA 33493