When I changed to Multi-Port Fuel Injection and a performance cam, I modified the breather/PCV system on my 1970 455 to be more like the system on the W-cars.

I put in a breather from each valve cover to the air cleaner housing, and sourced the PCV from the lifter valley.

I have roller lifters, which didn't leave enough room for a turkey tray. After attempting creative sheet metal work on the tray, I tossed the tray and started driving, I found that I was using 1 qt of oil every 400 miles. Compression checks out OK, so I finally realized the the lack of turkey tray meant the PCV was free to suck in oil splash from the lifter valley. I found some people on line who reported the same thing after modifying their Oldsmobiles' PCV similarly.

I mocked up my proposed solution and I'd like y'all to critique my idea.

If my idea looks alright, how would I attach the retainer under the intake manifold? The aluminum is about 1/4" thick in that location.


PCV at top of manifold


PCV intake port on bottom of manifold


Stainless steel curlies to drop out oil mist


Mockup of retainer for curlies

 

That may work well initially until the curly's get saturated with oil and crud. Or it may fix your issue, time will tell.

 

JB Weld?

 

What if you rigged up a catch can? Would that help?

 

I thought of that, Kenneth. But I wasn't sure about its durability exposed to hot oil. I'll go on their site to check it out.

Thank you.

 

Yes. I was concerned that the volume of oil caught would be very high. I tried to imagine the innards of a catch can--I envisioned some sort of steel wool--and thought about how I could replicate that without the need for constant emptying.

The Olds' breathers on the valve covers have fine fibers behind a fine screen but I've not taken one apart to see more.

Do you know what catch cans use to knock oil vapors out of the air stream?

 

I have two intakes with aluminum blocks welded into the exhaust crossover ports, so I wonder if welding an aluminum plate would work for your setup.

 

I intended to make the retainer of aluminum, so that would be a very secure method of attachment.

My only hesitation would be that this is somewhat of an experiment, so I would like to be able to more easily inspect or change the media if too much oil comes through.

I have a concern that I may use too coarse a media. That's why I asked about what's in a catch-can.

Coarse/fine is a tradeoff of filtering ability versus durability. And I don't want shreds coming loose inside the engine.

Perhaps I could incorporate some sort of securely-fastened door in the retainer for access.

Or make the retainer out of fine stainless screen to retain fine stainless wool. Then I could easily break it loose from tack welds and try again if necessary.

 

Here's the one I used...

 

Another option is changing the vacuum port location. I recall seeing a post where the PCV was connected to the oil fill tube. That should put it far enough from oil splash to prevent oil consumption.

 

The catch can is perfect in principle, but with my oil consumption, I'd have to empty that relatively small container every 200 miles or so.

Did you look inside to see what media it uses?

 

Thanks, Kenneth. Nice thinking! Even though there's pressurized oil spray for the chain, the cross-section of the tube is large enough that the oil mist will slow down and most will drop out. I'll do that if I can't figure out how to do it reliably in situ.

 

There’s also a baffle {?) in the block below the base of the oil fill tube to stop the oil slinging off the timing chain and gears. Or maybe it’s to stop junk dropped into the oil fill tube from getting into the engine?

 

Yes - I was thinking the same thing after you mentioned the oil fill tube....it's a stamped "squar-ish" piece of metal with a couple stiffening ribs in it. Sort of blocks off any direct shot from oil being slung around.

On the "manifold underside" metal structure you should be able to drill and tap some screw/bolt holes to attach that piece. I don't think I'd want to rely on epoxy. There are also special solid rivets made to hammer into a hole in aluminum to hold heat shields....used on some factory Chevy intakes with a formed steel heat shield attached to the underside of the intake/carb plenum area. These "rivets" have a sort of fluting in the sides that may dig into the aluminum. I bit more permanent compared to screws/bolts. I've used small bolts or screws in the place of these on a Chevy factory intake I redid for a customer. Had to remove the underside heat shield (and reinstall it) as part of the resto process.

On the factory valve cover breathers there isn't anything else to "see"....what you've already stated is what they are made up of.....fine screen with an aluminum fiber (I think aluminum) inside. Later (maybe aftermarket versions) can have a synthetic material inside of them instead of the alum wool/fiber stuff.

 

Here’s a good picture of the oil baffle.

https://classicoldsmobile.com/forums...-403-a-143679/

 

Easy solution is to use the oil fill tube. Another solution is go back to the valve cover PCV. I use about that much oil every 500, so I should pull my valve cover and make sure the baffle is there. If you want to keep that hole there, I think the best compromise between not sucking up oil, not having to change a filter, and not having something fall in the engine is to put a 90 degree elbow on that opening and run a thin wall pipe to whatever corner is convenient and furthest away from the center. It will suck from there and still get mist, just not splash. I don't think there is a way to cut down on the mist without a turkey tray.

Only other idea I can think of is put the filtering outside of the intake, right on top of that fitting, so you can 1, change it, and 2, it will drain most of it out when the car sits back into the lifter valley.

 

Just plug the PCV; you don't need it.

 

I know this is for an LS but I thought it could give you a visual. Some people have lots of trouble with PCV systems on LS motors and this is one of the solutions..

Good luck, let us know what you end up doing..

 

yup, just run breathers, you don't need a pvc, just make sure you have beffels in your covers.

 

Kenneth's idea gave me confidence that you could pull clean PCV vacuum from an area with an oil storm as long as you have an effective baffle in place.

I talked to my hot rod fabricator friends and then traded messages with Patton. We settled on using the stainless curlies under a close-fitting, aluminum baffle, spot welded in place.

Here's the final paperboard pattern and the aluminum cover.



I enjoy visiting the multi-generation family businesses in rural Texas. Here's the welding shop I'll take my cover to tomorrow. Those are the Rode brothers who run the shop their father built 64 years ago. Even their two sisters worked in the shop when they were in high school. All the children learned to weld.

Inside the shop is also a step back in time. There's a 1930s General Electric monitor-top refrigerator that they hooked up to supply cool water to the drinking fountain. And whenever you visit, there's a group of good-ol' boys sitting around talking (and drinking beer after 5 p.m.). Tony Rode, in the center of the picture, is the aluminum welder.

 

Ya don’t understand this. What is wrong with the pcv valve in one valve cover and the fresh air inlet in the other. Don’t over think it.

 

Maybe you don't understand the FIRST TWO paragraphs he typed in this thread.

 

IIRC, came from Mr Gasket variety pack of PCV grommets that I had kicking around. Remove the tube (or stuff it), drill it to appropriate size, I used some RTV or some sealer on it for good measure. When pouring oil I remove valve & make sure funnel spout is past the grommet.

 

Well done! If I were starting over, I'd use your solution.

You've got a creative fuel supply, too.

 

Re read both post. Still don't get it. There are plenty of later model engines with efi that use a pcv valve in one cover and a fresh air inlet in the other. I wouldn't call an older Olds with efi a later model engine. Pretty basic stuff

 

The W-30 OAI air cleaner set up (as well as 4 speed 442's with OAI) uses breathers in both valve covers with metal tubes running to the air cleaner base. It has nothing to do with the fact the car has EFI. The passenger side is a little hard to see in the pic below, but it looks like the driver side.

 

Breather in each valve cover. Went from pcv i modified onto oil fill tube to an inlet to a catch can, out the can to pvc port on carb.

 

Good ideas and nice installation.

How much oil do you get in your catch can?

 

Have to empty it out every 700 miles or so. About A cup of oil is captured by the catch can. Not burning any out the exhaust since modified set up.