That heated restrictor was a problem in the early Tiico engines.  It was not needed in South Africa due to climate.  Here in the northeast, it was needed, but did not come piped that way.  I ran into that problem, and it ended up blowing oil out my dipstick.  Took a bit of exploration to figure that one out.
Dave B.the Boston one

    On Monday, August 14, 2023 at 06:56:20 AM EDT, Dennis Haynes <d23haynes57@hotmail.com> wrote:  
 
 Yes I am aware of the rubber diaphragm. As passive device to help control flow during idle-low speed operation. There is also the restrictor which is heated to prevent it from being blocked by icing. 
I was just trying to explain the concept of a PCV system as used on other vehicles.

Dennis

-----Original Message-----
From: Alistair Bell <ragnarhairybreeks@icloud.com> 
Sent: Sunday, August 13, 2023 7:47 PM
To: Dennis Haynes <d23haynes57@hotmail.com>
Cc: vanagon@gerry.vanagon.com
Subject: Re: [VANAGON] Positive Crankcase Ventilation

There is a rubber diaphragm in the stock tower at the top.

Ab

> On Aug 13, 2023, at 9:44 AM, Dennis Haynes <d23haynes57@hotmail.com> wrote:
> 
> Looks like my repaly was blocked again. So here goes cut and paste.
> 
> 
> PCV=Positive Crankcase Ventilation.
> 
> This is the method of extracting piston blowby and other fumes from the crankcase for many vehicles. Note the Vanagon does not use a PCV system. It is basically an open vent leading to the engine intake between the air flow meter and throttle. The job of the tower is to let some of the liquid separate and return to the crankcase.
> 
> 
> 
> A PCV system usually consists of some type of metering device that connects under the throttle plate so that so that especially at low speeds the blow by and stuff is actually sucked out and fresh air pulled in.
> 
> 
> 
> Dennis