Exhaust Issues

[cgrantnavet]

What is the valve on my manifold used for and how do you replace it, or repair it. When ever the car accelerates there is a flapping sound from the valve I have turned it both ways and nothing it still flaps. Can someone give me a little help, oh yea where do you find a venturi vacuum amplifier?

Cedrick:banghead:

 

[demon seed]

What is the valve on my manifold used for and how do you replace it, or repair it. When ever the car accelerates there is a flapping sound from the valve I have turned it both ways and nothing it still flaps. Can someone give me a little help, oh yea where do you find a venturi vacuum amplifier?

Cedrick:banghead:

If this is the flapper where the exhaust manifold meets the exhaust pipe it's called the heat riser valve and it's for causing back pressure in the exhaust which forces the exhaust to travel up thru the transfer port, goes through the intake manifold and out through the other head. It's for carb heat and most have been removed long ago. I've never heard of a venturi vacuum amp unless you're referring to a engine driven vacuum pump that aids the vacuum booster on the power brakes (used with very high lift cams).

Terry

 

[sweatybetty]

it sounds like the spring is missing. there should be a bi-metallic spring that opens the flapper as the spring gets hot. they are for faster warm-up.
some folks take the flapper out and tap the holes in the manifod and screw in some plugs

 

[cgrantnavet]

Hey thanks I will complete this restore its just getting a little hard lol, thanks again

Cedrick

 

[Flatlander]

My riser was frozen shut when I bought my dart and the crossovers were plugged with carbon. Made 'er buck like a mule.

 

[cgrantnavet]

Yea that might be my issue as well, the car was sitting up for about 2 years and I had to tow it to the house. I had to change the fuel filter, rebuild the carb, put in another fuel line, change the oil, and flush the radiator just to get her to turn over. Now she is loping right on time with the exception of the flapping from that valve on the manifold. I might end up just redoing the whole exhaust system but well see. Thanks for all the help guys and Ms Betty.

Cedrick