Help me understand my dual snorkel diaphrams

[bobfist]

Hi!

I have a 383 71 with heated air system but want to know how it should work.

I looked in my mopar factory handbook.
I have it hooked up just like in the book, ever the original matching carburator.
When i start the engine the diaphram close the snorkel (the one without heated air)
And the other with heated air stays open.
Both diaprams works when i hook them up to direct vaccuum.
If i understand it correct in the book the snorkel without the heated air from the manifolds stays closed all the time
expt when accelerating or havey thottle and the vaccuum goes down.

Correct?

[A383Wing]

flappers should close when engine is cold and running. There should be a thermo valve inside the air cleaner to sense the heat and to open the valves when engine is warm enough.

The flappers will open when under full throttle or once engine warms up

[bobfist]

ok
one of my diaphrams stays closed all the time, it moves fine so its not stuck
its the one with the vaccuum t on it going to the carb

[A383Wing]

the vacuum pod nipples should not have a hose going directly to the carb...they should go to the thermal valve, then to intake vacuum. there should be a vacuum diagram under the hood to show routing.

[bobfist]

i have it installed just as in the factory book, thru the ATS
But one of the flappers stays closed all the time, is there different ATS sensors?

[A383Wing]

one sensor should operate both flappers if I'm not mistaken

[bobfist]

Looked at some dual snorkel restorations on the web.
Seems that the factory handbook hook up the lines the wrong way on the picture.
thats why my docent work.

[Nacho-RT74]

ok, I think I can post a diagram later, but here is how it goes:

on first start up, both are closed from a full unported vacuum tee on carb. With a T conector coming from carb tee, one goes straight to passenger side diaphragm pod, the other one to the temp sensor on air cleaner, then to driver side diaphragm pod

driver side opens when engine is warmed up. This is the one coming straight from temp sensor on cleaner

passenger side remains closed and just opens when no vacuum on system, so, when full throttle.

[bobfist]

So this one is wrong?

http://www.ebay.com/itm/70-MOPAR-DUAL-SNORKEL-AIR-CLEANER-383-440-CUDA-CHARGER-CHALLENGER-ROADRUNNER-R-T-/221454906883?pt=Motors_Car_Truck_Parts_Accessories&hash=item338fbdb603&vxp=mtr

[Nacho-RT74]

yes, is wrong. I had it just exactly like that untill checked the FSM

as stated, sensor gets two hoses, one from driver side pod, the other one from T conector. Passenger side goes straight to T conector. The last T conector Tee goes to Carburetor unported vacuum tee.

Same thing told but reversed LOL.

[Nacho-RT74]

to connect correctly the setup on the ebay air cleaner shown, need just to disconect the hose from middle tee of the T conector and run this hose to the sensor, where the short hose is... and use this short hose to feed the T conector from Carburetor

( in fact I'd relocate the passenger side pod hose to the middle T conector tee and use the outer tee to the hose to carburetor, saving that bend on hose... but that's just me )

[71 SE3834V]

Does this help?
The underside of my '71 before I pulled it apart to restore. Nacho is right on in how it operates.

[Nacho-RT74]

thats the way

[bobfist]

Ah thats whay i never see the other diaphram open, it opens when i drive
But then the snorkel at ebay i posted a link to is totally wrong.

[Nacho-RT74]

it opens at full throttle. that's the way it is

yes, ebay one is wrong...

[GreenMachine]

Here's some factory literature showing the cleaner air systems. There's some good info in these books, one day I'm gonna read them all.

http://www.imperialclub.com/Repair/Lit/Master/270/Page05.htm


http://www.imperialclub.com/Repair/Lit/Master/index.htm

[GreenMachine]

This section is more involved:

http://www.imperialclub.com/Repair/Lit/Master/271/index.htm

[GreenMachine]

more

[A383Wing]

one thing that I did not see mentioned is this: The vacuum line going to the carb from the air cleaner should go to constant manifold vacuum, not ported vacuum

[Nacho-RT74]

yeap, as I told, unported

[bobfist]

great info!
Thanks!

[billschroeder5842]

Random Factoid; My 75 dual snorkel with a 400 4bbl works identical.