PCV valve setup
 

I have a pair of older style ford motorsport breather caps on my 66 289, the kind that are just foam inside and have vent holes. I get a lot of blow-by and decided that it would be “healthier” to go to a PCV valve system. I got a Stant cap that would screw right into the valve cover like the old style did, and a push-in PCV valve, and connected it to the large vacuum barb on my Demon carb. I fire it up and I get an incessant rattle, from the PCV valve opening and closing at roughly half the rpm rate. The rattle doesn’t smooth out or go away, either.

Do I need a “deeper” valve (longer travel) that will stay open/shut? Do I need an air cleaner with an air barb so that I don’t connect to a vacuum source? Should I go back to the breather cap?

I welcome all thoughts and ideas,


Aaron

Re: PCV valve setup
 

You may just have the wrong PCV valve. I use the same valve covers that you have. I connect the PCV valve to the right rear valve cover using a rubber grommet with the PCV valve and a hose going to my Road Demon manifold vaccum source. At the front left valve cover, I have cap filled with wire mesh but with a hose connection below that which goes to the air cleaner. That way, there should be some suction to the crank case almost all the time.

I think the rattle may just be due the wrong PCV valve. Get one from a Mustang supply house that's right for the original 289. It should not rattle.

Rev

Re: PCV valve setup
 

Thanks, I will look into it an give it another try.