Does anyone have a picture or diagram/parts list for the PCV system on a '68 with a 302? I currently just have a twist on breather on the passenger side, but was interested in going to the factory PCV setup to reduce residue buildup over time.
From what I can tell, the passenger side valve cover is where the PCV valve is supposed to go, but I see variants of the valve that have threads and some that don’t, both saying they will fit a 68. I also found different versions of elbows, so I’m not entirely sure what is supposed to fit where. What was the original setup? Any help is greatly appreciated. Thanks.
I did some more digging, and it seems like the threaded PCV valves were for big blocks only.
Sounds like a 68 302 had a grommet with a PCV valve on the passenger side, attaching to a hose that connected to either the carb or intake manifold vacuum tree.
The driver side had a oil filler cap with a brass 90 degree elbow, then a hose running to the factory air cleaner housing. Can anyone confirm this?
I also have an aftermarket open filter style air cleaner, so no way to connect the driver side hose. I found posts where people used a breather here instead - thoughts? The obvious downside is that it’s not pulling filtered air, but would it also not be enough airflow for the system to properly work?
The Passenger side PCV had a valve with a built in elbow for the 302. You also need the thermostatic vacuum valve for the PCV - WCCC is the only source that I am aware of. The passenger side needs a vented breather, if you have an aftermarket air cleaner it should have originally come with a connection for this hose on the bottom side.
The '68 setup used the “D” shaped grommet in the valve cover, a straight PCV, a spacer under the carb (as cougarrand posted above) and a molded hose with two 90° bends in it. All of the parts are show in the NPD search below
Pics below are snips from Bob Mannel’s excellent book on the Small Block Ford, a very worthwhile investment for anyone working on the '69-earlier engines.
The bottom of my air cleaner does have a small slightly recessed circle that looks like it could be a knock out to attach a hose nipple, but beyond that, there is no way to attach a hose currently. It’s in rough shape anyway, so it’s been on my list to replace.
Thanks for the info, everyone. I’ll have to see if I have enough clearance for the carb spacer. If not, I can probably connect to an open port on the intake vacuum tree.
A few follow up questions:
My current breather and oil fill cap are push-on style to fit the round holes in my valve covers. Is that D shaped grommet for the PCV valve compatible? It doesn’t specify one way or the other.
Similarly, NPD shows the original oil filler cap on the driver side that attaches to the air filter as a twist on style:
I can’t find anything for the 302 in a push on style. Worst case scenario, could I install the PCV setup (as listed by Hemikiller) on the passenger side like normal, then take my existing push-on breather that I currently have on that side and just move it to the driver side? I’d prefer to connect to the air cleaner, but I might be out of luck if there are only twist-on options for the driver side.
What valve covers are you running? What carburetor?
You post was worded like you’re try to make a stock setup.
A PCV should never be attached to the intake manifold vacuum tree as it’ll cause a lean condition in that cylinder. It should always be plumbed into the carb base or a spacer designed for PCV use.
The valve covers are aftermarket ones that came installed on the remanufactured '68 302 I put in (when I got the car it had a '78 Mustang 302 with a blown head gasket). Carburetor is an Edelbrock Performer series.
The picture below shows my current setup, with just the push-in breather on the passenger side and rubber plug style oil cap on the driver side. I’m looking into the PCV system to cut down on the oily buildup over time out of the breather. I figured the factory PCV setup would be the simplest way to go, but as long as the end result works, I don’t mind deviating from the exact parts Ford used.
I do have that open (capped) vacuum port on the front of the carburetor - that would effectively be the same as connecting to a spacer right below the carb, right?
The large port in the front of the Edelbrock is the PCV port.
The issue with a lot of the aftermarket valve covers is they don’t have a baffle under the breather hole, and you will have a tremendous oil consumption issue with a PCV. Pull the push in breather out and look inside. If you there is nothing under it, then you have no baffle. The solution to that is a baffled grommet or a different set of valve covers. The baffled grommets are typically for a 1 1/4" hole.
I run this set of valve covers. They are the exact copy of the factory painted covers but in Chrome. Thay are baffled just like the original and work well. They are more expensive, but IMHO well worth the money.
My existing valve covers don’t have any baffle that I can see. I’m not against replacing them, and the ones that badcatt shared would fit the chrome dress up kit theme that would have originally came on my DGS package.
I’ll look around for an air cleaner that has the hose connection port as well. Thanks everyone.
