Hope this isn't stupid.  Are you better running a PCV valve from a larger displacement engine, such as an FE series, to adapt the Yblock to maximize flow from the valve?  Confused about if its better to vent the valve cover breather into the air cleaner or doesn't matter for a street car.

Hope to have body done in the spring and tear the engine apart this summer with goal of cruzin this fall.  Getting closer.

Thanks John. No I wasn't thinking about it for mine with the blower. It was just a thought I had. I was concerned about the oil splash from the begining. I'll stay with my current PCV setup. Chuck in NH

Y's guys rule!
Looking for McCullouch VS57 brackets and parts. Also looking for 28 Chrysler series 72 parts. And early Hemi parts.

MoonShadow, 292 w/McCulloch, 28 Chrysler Roadster, 354 Hemi)
Manchester, New Hampshire

You're correct about the crankcase pressure, but the PCV valve should close under pressure or a backfire. That's to prevent a crankcase explosion if you've got a lot of fuel contamination. I've never had that happen. I have been concerned about moving all the crankcase pressure out of the hose from (in my case) the oil fill tube to the suction side of the air cleaner, but I'm not getting a lot of oil in there. And I haven't blown the gaskets out of the valve covers or the pan. Probably because a street car doesn't spend that much time under boost, but the dyno pulls weren't a problem either (till the head gaskets went from the load of oil when not under boost) through the PCV valve. I had a high mileage factory turbo car, and we found a lot of oil in the intake, pulled the turbo and had it gone through, and was told the seals were ok, it was blow by. I know some racing motors run crankcase evacuation systems, but I've never had anything that extreme.

miker
55 bird, 32 cabrio F code
Kent, WA
Tucson, AZ

Chuck:

Think about it.  How common are leaks in the draft tube area on the side of the block?  Must be a lot of spash there.  I would think a pcv would suck up a lot of oil, and if you put a hose to the aire fileter, and there was a slight vacuum in the air filter, it may even suck oil through the hose and directly into the air stream.  I don't think you want that either.  And if you're referring to your blown car, pressurized air blowing down that hose into the crankcase isn't a very good idea, you want to get rid of crankcase pressure, not increase it.  Just my humble opinion.

John - "The Hoosier Hurricane"

Me niether! It's just something I noticed while looking at the VW block off plates. Chuck

Y's guys rule!
Looking for McCullouch VS57 brackets and parts. Also looking for 28 Chrysler series 72 parts. And early Hemi parts.

MoonShadow, 292 w/McCulloch, 28 Chrysler Roadster, 354 Hemi)
Manchester, New Hampshire

Lots to think about here and from lots of experience dealing with the thoughts behind modifying, replacing, or combining a PVC System to function with an original or modified road draft tube. I need to confirm I have this correct. If I want to install a PVC system, I am thinking the "closed system" would be a good choice. Again, if I understand correctly, this can be accomplished by using a valley cover that will accept a PVC fitting. From the PVC fitting, run a hose to a vacum port on the carb. To close the system, use a non/vented oil fill breather  cap with a port to connect an air line from the oil fill cap to another port installed in the bottom of the air cleaner?

This would close the system, providing the oil fill cap is not a breather.  I am waiting to see how the question regarding a PVC fitting to replace the road draft tube in the side of the block is answered. I have never heard that option disucssed.

Thanks for all the information and help.

Darrell Howard Outlaw 56

Whitefish, MT

Darrell Howard Whitefish, MT Outlaw 56 Ford F-100's

I've looked at the VW oil block off plates (that will fit the block where the draft tube is now). Most of them have a threaded bung in the center. I wonder if a PCV valve could be placed down there or would it pick up oil splash. Also, along the same Idea to run a hose from there to the Air cleaner? Any thoughts? Chuck in NH

Y's guys rule!
Looking for McCullouch VS57 brackets and parts. Also looking for 28 Chrysler series 72 parts. And early Hemi parts.

MoonShadow, 292 w/McCulloch, 28 Chrysler Roadster, 354 Hemi)
Manchester, New Hampshire

I did the same as Mark as I simply put an expansion plug in the road draft tube hole of the block when I installed the PCV system.  I did cut the small oil drain tube off of the road draft tube assembly and reinstalled the modified assembly back on the engine for appearance purposes only as the road draft tube itself is totally non-functional now.

 

Doing a search on this site regarding road draft tubes comes up with an inordinate number of queries around the oil leaks from these tubes and that alone is enough to warrant getting them off of the engines or making them non-functional as I did.

Lorena, Texas (South of Waco)

I was told that the PCV system was originally use on milk and ice delivery trucks, as they didn't put on enough high speed (25mph) miles is the city to make the draft tube work. Some of still drive like that due to traffic. I did a PVC on an older car, and didn't provide enough intake air under heavy vacuum (from the oil fill tube on a Y block, or a plugged oil fill cap), and on a long downhill stretch with high manifold vacuum, I sucked one valve cover gasket into the motor, and then spilled oil all over the exhaust manifolds. Makes a lot of smoke. Not enough PCV valve and hose will blow them out, so pick a valve from a like sized motor. You should also consider a baffle on the valley cover, I had one motor pick up enough oil off the dist. gear to get it into detonation (it was a blown motor), and take out the head gaskets. Still, I run closed PCV's on both my Y's, and also on the old scrub.

miker
55 bird, 32 cabrio F code
Kent, WA
Tucson, AZ

The opening in the valley cover will take a grommet which you can buy at most auto parts stores.Measure the diameter of hole and get the correct size grommet.The PCV valve goes into the grommet and then run a fuel line type hose from it to the fitting on carb.Make sure the oil filler cap is clean and that air can be drawn in through it.If you really want to do a closed system get a cap with hose fitting on it and run hose to air filter.You can plug the hole in side of block where draft tube was using a frost plug and grinding a flat spot on each side where the bolts can hold it on block.Thats how I did my 56 292.The dual feed option is for high performance use where you need a constant supply of fuel quickly to feed the primary and secondary fuel bowls instead of feeding the secondary bowl from the primary with the transfer tube.