37, 120 heat riser question

Posted by rvsls On 2012/7/23 20:56:18

While trying to solve my vapor lock problem on my 37, 120 coupe convertible, I realized that there is a heat riser on the exhaust manifold and it appears my car is missing parts.

All that exists on the outside of my exhaust manifold is the shaft extensions on both the front and the back. The front shaft has a slot for a spring and the lug exists on the manifold for the spring but no spring.

On the rear side all that exits is the shaft which has a pin running through it.

Obviously, I need parts to put everything back together but for now I just plan to wire the shaft open as the carb heat is not really required in 90+ weather.

My question is how do I determine the open position? The shaft was frozen when I found it but I have now freed it up but I am not sure of which way the shaft should be turned to open the valve.

Any help would be greatly appreciated before I have to take things apart!!!

Rod