Re: Lever thingy on exhaust manifold?

Posted by Bob J On 2023/1/12 9:15:16

Yes, the counterweight on the heat riser valve holds it in the 'warm' position. This is a fail-safe so that the butterfly does not stay in the 'cold' position and allow the exhaust gases to rise continually as that would overheat the carb and possibly burn the valves. Drove my 261 Pontiac straight 6 for about 100,000 miles over 30 years with the heat riser valve rusted open with no issues. Winter and summer too, back when we had winter! No wire needed as gravity is your friend in this case!
Bob J.