Hi All, Recently purchased a 31 pickup with roller setup 327. It has the taller valve covers to accommodate the roller valves. It currently has a breather on drivers side front on valve cover, filler neck and one on the passenger side back valve cover. There is no PCV. I plugged hose coming from base of carb to prevent vacuum leak while I figure out the PCV thing. I understand the importance of the PCV. The breather on back passenger valve cover is constantly leaking engine oil at higher RPM which drips/sprays down on to the headers. I tried adding a PCV valve t this and ended up pulling oil into manifold. Currently I have a rag stuffed in the bottom of the breather. The valve cover has a nice compartment which should prevent the oil carryover. Not sure if its possible to take valve cover off and rotate it on the same side so the hole is a the front. Would this reduce stop the oil carryover? Not sure if there is less oil spray at the front of the head. If not what else could I try? If I do get a PCV valve installed is it required I reset the idle mixture screws on the middle rochester 2 barrel. Its a tri-power setup. The breather on the drivers side has no problems with oil coming out breather. Oil pressure is high. Shoing up to 60 psi when RPMS up. Has Comp. Thumper cam low idle vacuum 3 inches of Mercury. I've marked on pictures to explain how its setup. Thanks in advance.
if it's a 327 the block should have a spot for a pcv back by the distributor are there baffles in those valve covers?
Yes the valve covers have baffles. I don't see a spot to stick a PCV valve on the block by the distributor. Only spot is where the oil pressure sensor is mounted. Block is out of a 1968 Chev Pickup. 2 Bolt main.
Take one of the breathers off, install PCV grommet and PCV valve and route it to the center carb.. Might have to install a vacuum plate under the carb to hookup the PCV hose if it doesn't have a vacuum port...
I concur with scrapmetal48. I'd pull the breather from the drivers side, buy the pcv grommet, pcv, and hose. Run that to your center carb. Leave the passenger side breather as is. You really should be running a pcv valve with your setup. I had a similar problem years ago with a 327 I was running. It was blowing oil so bad out the breather, oil was running down my windshield. No matter what I tried it kept blowing oil. Turned out I had a cracked head and a crack in the block. I hope that's not the case for you. For me it was a blessing in disguise. We pulled the engine and swapped it out for something I'm much more happy with.
Not sure of the exact year however since you havean oil fill tube you can use a late 69-70s fill tube with a connection for screw in PCV valve that can run to a hook up in your valve covers (current "breather" Look on line for the exact combination this setup is a viable alternative to a "road draft tube"
There have been several PCV threads on here....google them. Short answer as I have to go to work now...I was going to drill a hole in the manifold behind the rear carb for a PCV grommet and valve and use the filler cap breather on the filler tube as my valve covers are old Corvette finned w/o holes
I can install the PCV on the drivers side without issue. I'm not sure why passenger side is blowing oil out with baffle in valve cover. The breather is currently plugged to keep oil from coming out. Only other breather is on the oil fill tube. Is that sufficient? Any tips to rectify oil blowing out? Can I swap valve cover so hole is at the front of the head?
Valve covers don't care which way they are headed. I would get a oil fill tube with the pcv fitting, use the breathers on the valve covers with sweat bands over them. When the sweat bands get nasty just replace with new ones. We been using the sweat bands for years or you could just use a sock.
Geoford41 is also correct. 67-69 Z-28's have a filler tube with fitting for a screw in PCV valve. The top has a 1/4 turn cap that needs to seal. I've got one of those fill tubes. Swap meet $5.00. Your breather can be on either side and one will do. You can tell if your PCV system is working correctly by removing the breather and placing a piece of paper over the hole when idling. If it stays there it's ok. Should be slight vacuum.
How do I remove/replace fill tube with screw in type PCV? Can you just remove by rocking it or pull straight out. Looks to be pressed in from what I read. Do you know the exact car its from so I can go to store and order one along with the correct screw In type PCV. I've never seen screw type PCV. I seen on You Tube someone purchased a rubbered deep baffled type grommet with demister pad in the bottom of it that the PCV sits in. Its suppose to stop oil flow into the PCV. Can only find it on eBay. Thanks.
If you haven't removed the valve covers yet, it might not hurt to see why the pass side is experiencing a problem. Maybe the oil drain hole is blocked or baffle is not properly attached. This link has a picture of the pcv in filler tube that is mentioned above: http://philsl79.com/engine-l79-intro.html
I have never used a PVC valve on my engines. I have nearly the same set up you have on my 350 for over 10 years. Tube breather in front, Moon breathers on each Cal-Custom valve cover. It would occasionally spit oil out of the front tube during hard driving, I added some filter media and it stopped spitting. Beautiful engine by the way!
Nobody answered cubsys ? on removing filler tube? I would also like to know if there's a way without removing manifold!!
Simply remove one of the valve cover breathers and install a PCV in a valve cover grommet (I got mine at NAPA) the picture below is a 327, HRP
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