Question on Air Cleaner Flapper Valve

[J4GRAND]

On my rebuilt 360 in my 73 J4000, I have noticed that when I open the throttle, the flapper in the air cleaner snorkle will close. I have been following a thread on the FSJ-List that was dealing with oil in the filter housing which is a problem I'm having. I replaced the PCV valve and cleaned the oil cap thoroughly so I'm wondering if this flapper closing could cause extra suction on the cap and/or PCV to cause this oil in the housing? Is this flapper supposed to be open or closed upon acceleration or do I have some vacuum lines crossed? Or a bad controller to this flapper?

[joe]

It's supposed to open under acceleartion. It's only closed when the engine is cold drawing heated air up from the heat tube/stove and when it warms up to 115*F I think the flapper opens to draw air though the air cleaner snorkle and closes the heat tube off but hot or cold the flapper should open under heavy acceleration.

[rhamby]

With the engine off, can you move the flapper by hand? I mean, is it really loose, just flapping (no pun intended) like it's not connected to the vacuum pulley? If it is not connected to the pulley, the air flow under acceleration could suck the flap up, forcing all incoming air to come from the heat shroud.

[badaboom]

Ditto

joe
rhamby
Comments

What is it called TCI ?
Thermoswitch Controlled Induction

"this flapper closing could cause extra suction on the cap and/or PCV to cause this oil in the housing?"

Possible? Sure.
Just keep tabs on the air filter cansister
once you have the snorkel/flapper issue resolved.

Good Luck

[Zacko]

I had the same problem and wasn't interested in making it work right so I disabled both "flappers" as soon as I did the extra oil in the air cleaner went away. (I can live with a little longer warm up time!)

[mtn goat]

Sounds like your delay valve is broken or not hooked up. check your vacuum routing and see if everything is hooked up how it is supposed to be.

[J4GRAND]

I know that the flapper is working off of vacuum- it closes only a little when lightly bumping the throttle but if you go to WOT, it closes all the way and when you let off, slowly opens. I bet the delay valve is hooked up backwards or is bad- I'll check it tonight.