Nuther heat riser question

[Standing Elk]

What is the threaded stud that is just above the heat riser assembly on the manifold for? Is it just there to hold spring tension? 

[ggdad1951]

I believe you are correct.  A picture would help with what you are looking at JIC.

[Desotodav]

Does this answer your question S E?...

 

Desotodav

[Merle Coggins]

It also acts as a stopper for the counterweight for the heat riser, so that it can only swing so far.

[TodFitch]

And, as a point of trivia, for the first year this basic engine was used in Plymouth cars that stud was actually a tube with a small check ball. The assembly works as a manifold drain so if you flood the engine when trying to start it the gas has someplace to go. Check valve ball assembly was to keep you from having a large manifold vacuum leak when the engine was running. It was the first year for a down draft carburetor and they worried about that as the older updraft carburetors simply drained out the air intake if you flooded them. Didn't take long for them to decide that they did not need a drain there with a automatic check valve that might fail and they replaced it with a stud.

 

I haven't looked at a later intake manifold stripped down and up close, so I don't know if the stud hole goes through into the intake passages like they do on the '33 Plymouth or not.

Edited February 1, 2013 by TodFitch

[Dodgeb4ya]

There is a tech section up top showing excellent pictures and all your needed info. Check it out you will probably like it and get a full understanding of hoe the heat riser operates.