Fox Body Mustang Valve Cover Question

[377]

I’m looking for some fairly low profile plain valve covers for my 351w, I’d also like them to be cast aluminum. I have always had better luck with cast covers not leaking. So I found some Fox body valve covers that seem to fit the bill. My question is there are no provisions for pcv or breathers. The oil fill tube has a nipple coming off the side of it and that’s it. Can anyone enlighten me to how I could use these on my 351w. Thank you for the help.

 

[jedblake]

You could use a hole saw and use a grommet that a valve can be inserted into. I believe the opposite side of the valve cover inside has a boss where you could mount a splash shield like the other side has.

 

[377]

Thanks Jed! I was hoping it would be as simple as putting a hole in there for the pcv. One question you might have the answer to. On the oil fill tube there is a small tube/nipple coming off the side what is that and where would a line go from it? Thanks again.

 

[DirtDonk]

That's actually for the PCV fresh air return.
On the 5.0 engines the PCV valve is in the back of the intake manifold instead of the more traditional valve cover location. Many (if not all?) of the 5.8/351's used the old valve cover location though.

The nipple on the oil filler runs a hose from there to a matching nipple/barb/thingy on the throttle body on most applications. On a few applications I think I've seen the hose running to a fitting on the intake tube, but most run to the throttle body.
Whatever setup you're running, as long as the fresh air return is behind the MAF, but ahead of the throttle blade (so that it does not see full manifold vacuum) you're good to go.

The air sucked out of the crankcase by the PCV valve has to be replaced by fresh, filtered air. But since it is part of the combustion process, on a MAF engine it must be behind the sensor so it gets "counted" by the computer.

Paul

 

[DirtDonk]

One bit of trouble you could run into by simply cutting a hole and installing the valve in your valve cover, is oil consumption. From the factory there is a pretty well designed oil baffle to keep both direct oils splash from the rocker arms, and general oil vapor from being sucked into the valve in too large a volume.
If you don't make some kind of baffle you run the risk of sucking a lot of oil into the intake, and having it pool around in places it shouldn't and generally making a big mess.
Well worth doing right.

Not sure if there is any set-in-stone way to do it the "right" way though.

Good luck.

Paul

 

[377]

Thanks for the help Paul. I was looking around last night and figured out it was the fresh air side of the pcv “system”. My 351 will be running Holley Sniper EFI so I’ll plumb a line to the bottom side of my air cleaner. As far as a shield on the pcv side I found a baffle Moroso makes that I’ll use to keep oil from being splashed into the pcv. Thanks again for the help.