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Manifolds and flappers!

Kevin Bisgrove

Well-Known Member
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Sep 22, 2018
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Location
Victoria, BC
First off - Can I get the flapper out of the manifold? I have the pieces all off but didn't know how to get the flapper itself out.

How and what does this flapper unit do? There is a coil of some sort on one side with a spring and the other side has some type of flint or wire bunch piece almost like sos pad material maybe? They were not in the car when I got it.

I got the whole unit loosened up and moving freely!

Planning to blast the manifolds and finish. What thoughts do people have on finishing them? I'd like to leave them like factory but don't want the rust and unfinished look. A friend painted his black but I don't think I want to go that route... open to suggestions!

Kevin
 
If your not going for 100% original remove it with extreme prejudice, tap the holes for pipe plugs and be done with it. Those things were a horrible idea, they basically choked the exhaust so the manifold would heat up quickly sending heat to the air cleaner. From the factory it would have had a stamped metal shroud around the manifold then a hose going up to the cleaner.. usually under the snorkel.
 
I blasted and painted mine with Eastwood cast iron manifold paint. They have held up very well for almost 30 yrs. I also put anti-seize on the nuts, especially the sleeve nuts, and they all came off easily when I had to change the gasket after 20 yrs.
PB300003.JPG
 
From the factory it would have had a stamped metal shroud around the manifold then a hose going up to the cleaner.. usually under the snorkel.
The older cars didn't have the sheet metal scoop outside the manifolds.
I also wouldn't say it was a horrible idea either. Even with the newer style heat riser that was captured by the air cleaner
the early seventies small blocks were pretty bad for "icing" when the temperature was in the mid 30's and the air was damp.
Which happens frequently here in the Rochester NY area.
But since my cars aren't driven in this weather I removed the heat riser valve completely in my Charger.
I found a 3/8" tap and a longer bolt run right into the shoulder where it became an interference fit worked well.
Then I cut off the excess on both inside and outside.
 
Kevin, the "flapper", or valve, is welded to the shaft. You have to grind the weld off to get it out. This usually destroys the valve and shaft. There are rebuild kits available. The coil spring holds pressure to close off exhaust when it is cold and force exhaust up through a passage into the intake manifiold to warm the intake air for better and quicker warm up and driveability. When the spring heats up from manifold temp it allows exhaust pressure to open the valve above idle and let exhaust flow. The tiny coil spring and "pad" help keep it quiet (rarely),,,Back in the day when we were hanging out at the local burger joint we could tell a BB mopar was coming through by the "Chink-a chink" rattle of the heat riser!!!,,,Ed
 
I just tack the flapper wide open and return the spring and lever to make it look correct.
beerestoration2017 245.JPG
beerestoration2017 755.JPG
 
I have never seen that attachment. I did just remove the heat riser valve from my manifold, and tapped it and installed pipe plugs.

heat riser.jpg
 
I cut the GTX's flapper off with extreme prejudice. The last pic is a stock photo on how it's supposed to look from the factory

DSC01935.JPG
DSC01934.JPG
Exh. manifold heat riser.JPG
 
The older cars didn't have the sheet metal scoop outside the manifolds.
I also wouldn't say it was a horrible idea either. Even with the newer style heat riser that was captured by the air cleaner
the early seventies small blocks were pretty bad for "icing" when the temperature was in the mid 30's and the air was damp.
Which happens frequently here in the Rochester NY area.
But since my cars aren't driven in this weather I removed the heat riser valve completely in my Charger.
I found a 3/8" tap and a longer bolt run right into the shoulder where it became an interference fit worked well.
Then I cut off the excess on both inside and outside.
I don't doubt that it helps with warm ups one bit, I say it's a horrible idea for the simple fact that you have a moving part that can cause serious performance problems mounted in the most hostile environment you can think of. Everyone of them I've come across are seized.
 
Yes but they worked OK when the car was driven regularly.
At least for 10-15 years which is generally how long the cars lasted.
This was kind of the price to pay for having a "dry intake" arrangement.
Or would you rather run coolant through the intake?
 
I like this idea and think I'll do the same. Better to remove it completely out just weld it wide open?

What did you finish your manifold with? I like the look!
All depends what look you're going for. If you remove it, you have no shafts to replace the counterweight and bimetallic heat spring onto.

VHT manifold paint in cast iron colour and then heat baked per the directions. All in my restoration thread....
 
All depends what look you're going for. If you remove it, you have no shafts to replace the counterweight and bimetallic heat spring onto.

VHT manifold paint in cast iron colour and then heat baked per the directions. All in my restoration thread....
I'll search it on your thread, thank you!
I want to keep original look at I'm going to copy you
 
All depends what look you're going for. If you remove it, you have no shafts to replace the counterweight and bimetallic heat spring onto.

VHT manifold paint in cast iron colour and then heat baked per the directions. All in my restoration thread....

I searched on your page thread a fair bit. Could you point me in the direction of your manifold clean up?

It would be really nice to have your pages tagged like moparnation! I usually look to your stuff for ideas and know how
 
I searched on your page thread a fair bit. Could you point me in the direction of your manifold clean up?

It would be really nice to have your pages tagged like moparnation! I usually look to your stuff for ideas and know how

I found it... just need to learn how to use the search function better than I know how already!
 
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