Posted by Bruce B. on Monday, September 05, 2005 at 10:41PM :
In Reply to: Chris posted by Clint Dixon on Monday, September 05, 2005 at 6:16PM :
Since my engine is being put back together and is accessible, I thought I'd check out the "Donaldson" valve. (1958 engine) I cleaned the valve and was dismayed to find it flowed both ways. Upon disassembly, I could see that there was no way it would stop backflow. As I pondered this, I checked the parts book and sure enough it is called a metering valve. When I sucked hard on it (no jokes here) I felt the valve operate and restrict the airflow, just as one would suspect at higher RPMs. A newer PCV valve would stop backdraft, but wouldn't slow airflow at high speed as seems to be the case here. BB