heat riser or manifold heat control valve...how to wire "open"???

[Steve W]

Climbed under the car today and I noticed that while the mainfold heat valve moves pretty freely...but the end of the spring is NOT connected to anything. So it just sort of stays wherever I leave it.There is a thing that looks like a nail connected to the  manifold..I am assuming that is where the spring should attach?

But...I live in Los Angeles, do I really need this thing to close?

And...what is the orientation of the lever when it is supposed to be fully open??? I would just like to try and wire the thing open, but which way is open???

Thanks for all the replies!

[R Schroeder]

I looked up a 68 heat riser. If yours looks like this, the weight needs to be in the up position.
No, you dont need them. I have mine held open on my car.
Roy

As you can see in the site, most of them the weight is out to the side when cold.

http://www.hamiltonmanufacturing.ca/hrv.htm

[Steve W]

Thank you Roy!! That's exactly what I was hoping to see.

I took a guess at it today and wired it so that the lever was in-line with the direction of the exhaust gasses.
Kind of like the natural gas line that feeds the water heater in my house...straight up is open...full left or full right is closed.

That picture really illustrates the point. Thanks again!

[cadillacmike68]

Has anyone ever welded it open (or replaced it with a spacer) and then welded up the crossover ports on the heads, intake and exhaust manifolds? in La and in FL it's never needed, and even Roy in WI doesn't seem to need it. Further, when the engine is hot, all it does is boil the fuel in the carburetor float. 

[R Schroeder]

Well Steve , you assumed correctly.
Heat risers are nothing more than a PITA. They are only on for a short period of time , while the engine warms up.
Usually when I need info on something , I just Google it. I then hit images and you will find the picture you need, or a web site will have a picture, such a NAPA.

  Mike, replacing it with a spacer is nice if you can find one. As the cars get older its hard to find these. My 78 did sell one at one time , but it is hard to find now.
Basically you just need to make sure they are open , if they don't function right.
Even though I am in Wisconsin , I don't drive the car in cold weather. If I did it would only mean I would wait a few minutes for it to warm up a bit anyway. These heat risers are not on that long anyway.
You don't need to weld up the cross over in the intake manifold either, because it isn't being directed to the manifold. I have repainted my engine, and it isn't burnt off the manifold where it crosses over, so I know mine is not closed.
Roy

[Jon S]

The advantage of the heat riser valve pertains to warming the climatic control on the automatic choke so the choke opens quicker; thereby, kicking the fast idle cam down sooner.  Mine had been wired open for years with no performance problems here in New York, but I just bought a new one (Studebaker is the same unit for 1/3 the cost) since I'm hearing a slight exhaust leak from the original heat riser valve.  The '58 had a long tube from the exhaust manifold to the climatic control on the carburator and the heat riser valve diverted all the exhaust gasses to the passenger side exhaust to provide greater pressure and heat to this tube.

[Steve W]

Thanks guys.

Well, when I first got under the car to inspect it, I noticed that the lever, with the weight on the end,  was indeed off to the side, or in the closed position. And there is a post that looks like a nail protuding from the unit with nothing on it. From the pic that Roy was kind enough to research and post, that is what the big "thermal coil spring thing" is supposed to attach to.
However, most of the thermal coil spring is actually missing on my car...(broken and fallen away over the years I suspect)...there was nothing to open the valve, so it has been in the closed position for I don't know how long! It does in fact move back and forth freely when I move it by hand, so thankfully it wasn't stuck closed.

I have now wired it in the open position and will be keeping a eye on it!

Thanks again!