See the flapper valve with the counterweight. Apparently it is always in the closed position. I have attached the braided rubeer vacuum hose to the tube on the side of the oil filler square. But it never opens to fresh air. So wouldnt it being runing rich all the time. Does it ever open to fresh air. Should I remove the valve out of the air cleaner. Let me know.

Thanks all
Ted

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I don't have the answer, but you're a mind reader. I picked up one of these just yesterday and was musing over its exact function. Air control of some kind?

Probably some way to regulate air flow/pressure/vacuum. Either for drivability or emissions as those were both issues when these cars were new.

I always figure that the factory wouldn't have spent the money to engineer, purchase, and install these sort of things if they weren't needed for one reason or another, so if it's working and free, don't play with it.

I too would like to know the function as I have the same set up on my 71....

From what I have found this counter weight flap ensures that the engine works only with pre-heated air at idle, when the airflow increases the flap opens for non heated air.
In -72 this system was replaced with a more sofisticated one sensing both air temperature and intake air pressure and no counter weight any more.
I would guess that the main reason for having this is emission control, but it could also benefit to driveability.


/Lars S

Only the '72s had the hot air supply to the air cleaner, and it was operated by a thermostatic controlled vacuum valve.

The Cap'n

Mines is a 71 there is no plumbing for hot air. So is it safe to ASSUME that flapper will open up as I am driving ?

Yes the flap will open when you go driving (or rev it at neutral) as the intake aistream increases.
If there is no hot air connection my guess is that the flap is there to increase the crankcase ventilation at idle.

/Lars S