exhaust manifold spring question

Hi,<P>I couldn't find this in my shop manual so I thought I would post it here. On the bottom of my exhaust manifold, right where it meets the exhaust pipe, there is a small spring. It's hooked up to the "flap" (not sure of the term) that's inside that latter part of the exhaust manifold. (What's that thing called anyway - heat riser??) Anyway my question is where is that spring supposed to be hooked up to? Is it supposed to keep that flap open or closed. There is also a second spring on what would be the front side of the manifold which looks like a bi-metallic spring that would open as it warmed up. I just can't figure out where that small spring should be connected and I think that flap is free to move as I drive and it warms the car up. I'm pretty sure it will run cooler as soon as I fix this.<P>Thank you in advance.

There was originally a tab that attached to the exhaust pipe bolt . The little spring attached to the tab and its purpose was to keep the heat riser butterfly from rattling.

So in other words, the small spring should be pointing straight down toward the exhaust pipe? -Thanks.

Hi,<BR> Well it is called the heat riser or early fuel evaporation valve, yes the bimetal spring tends to open it. The valve's purpose is to be shut during cold start up to direct exhaust gas up under the base of the the intake manifold below the carb to help evaporate the fuel and keep it in the air/fuel stream until the engine heats the intake enough on its own, as the engine warms up the EFE valve opens as stays open at operating temp. If stays shut you may have some lack of power hard starting or both due to leaning out of mixture.<BR> According to my 48-49 shop manual page 3-13 fig 3-16 show the spring you are talking about as an anti rattle spring which connects to bracket off the valve shaft you bend the bracket to prevent chatter of the valve.<BR> One more thing if your bimetal spring is bad it is best to wire the valve open if you don't replace it, during the summer months you won't have much wram up trouble with ou the valve shut.

oops forgot to mention they show a bracket to which the bottom part of the spring hooks to as being attached to the pipe to manifold stud, you can pobably make one out of 18ga steel or a cabinet corner brace

Is there any way that you can tell what the open position is? I noticed that when I rev the car the flap moves but I am unsure of what the open and closed positions are. I should have written it down when I had the exhaust manifold off - but you know how that goes - I was convinced that I will remember. Ha!

Hi Crin,<BR> Just went out to look at a '50 Super engine I have, it appears the valve opens when the weight (above rattle spring) moves away from the block out toward fender.that would be CounterClockWise viewed from drivers seat.

Thanks Scott,<P>I was messin' around with it last night and with the help of a diagram and some detective work I kinda figured that out. I'm glad you verified what I thought was the correct position. I also found that the bi-metallic spring isn't quite working as it once was. It's not opening the valve at all so I'll just leave it in the open position as the car sits in a heated garage and I never have to start it 'cold'. Thanks again for all your help.<P>Cheers!