Valve Cover Breather questions

[ArmyWarrant]

I am running a 306 with world products windsor j/r's and a victor jr intake with a holley 600 CFM Double Pumper. My question is do I need to run a breather on the valve cover if I the passenger cover has a PCV valve in it? I am getting what I think it a lot of oil coming out of the breather is why I ask.

[Rodeheaver's]

you should pull the valve cover that has the breather in it and see if there is a baffle in the cover, if there is no baffle, oil will make its way into the breather..

[ArmyWarrant]

you should pull the valve cover that has the breather in it and see if there is a baffle in the cover, if there is no baffle, oil will make its way into the breather..

There is no baffle in there, but I changed my valve covers and the old ones had the same prob, just not as bad as these ones with out the baffle. Should this be something I should worry about?

[Hawkeye]

1st, get a baffle in that valve cover. 2nd, Is your PCV working? Pull it off and see if its sucking. Does your dipstick ever pop out after high reving? Those are some of the things Ive sdeen in the past, on some of my vehicles.

Other options include running your breather hoses down to your headers (assuming you have headers), however, this only works if you have race mufflers or straight headers. Another option is to run an evac pump, however, that's like 800-900 bucks for a good one. ( I doubt you need this as it usually a race only)

How much oil is "alot"?

[ArmyWarrant]

I believe the PCV is working but I'll check, never had the dipstick pop out. there are no hoses on the breather its one of the ones that you get at the parts stores that pushes into a grommet. I will get the baffles in tomorrow from the old covers. two of the holes don't line up but I will make them work even if I have to redrill the holes.

This is what the oil looked like after draining off the cover for 30 mins

[Wolfpack Speed]

I am running a 306 with world products windsor j/r's and a victor jr intake with a holley 600 CFM Double Pumper. My question is do I need to run a breather on the valve cover if I the passenger cover has a PCV valve in it? I am getting what I think it a lot of oil coming out of the breather is why I ask.

If you run breathers you should have 1 on each valve cover and delete the pcv. If you want to stick with the pcv you should not be using breathers.

[blkp42e]

How would you delete the PCV mike? maybe this is the issue i have been having

[Wolfpack Speed]

How would you delete the PCV mike? maybe this is the issue i have been having

What I did on my yellow cobra was removed the check valve and plugged the intake. Deleted and capped off all pcv and related lines, then popped a breather in each valve cover. Along with deleting just about every vaccume line and useless component on the car, the engine bay was clean as hell and ran like a champ with no issues

[Jivepepper]

How would you delete the PCV mike? maybe this is the issue i have been having

I hollowed my pvc out and run bought covers to a 1QT vented catch can.







A link to it.
http://store.summitracing.com/partde...0&autoview=sku

[ArmyWarrant]

If you run breathers you should have 1 on each valve cover and delete the pcv. If you want to stick with the pcv you should not be using breathers.

Would running both be the cause of the oil? I am just worried that there maybe other issues. I won't have a garage until october to be able to put the engine on a stand and go through it. Also if I was to stick with the pcv valve setup how should it be run. The Originial owner has it tee'd into the rear vacuum point coming off the carb. and it also goes to the vacuum tree supply. Is this ok or is there more to it?

[somethingclever]

If you run breathers you should have 1 on each valve cover and delete the pcv. If you want to stick with the pcv you should not be using breathers.

Then why do all modern and even pre-efi cars and trucks come from the factory with an air inlet on one valve cover (breather) and a PCV on the other side?

[u1arunit]

Then why do all modern and even pre-efi cars and trucks come from the factory with an air inlet on one valve cover (breather) and a PCV on the other side?

The ones with an air inlet on the opposite side usually breath via metered(closed) air. Most cars are this way now.

If the PCV is left hooked up and a breather open on the other side it introduces un-metered air into the engine and creates a vacuum leak as well.

[ArmyWarrant]

OK thing is I am running a carb and not EFI does that make a diff? The PCV line is going into the baseplate on the back of the carb and is tee'd into the line that supplies vacuum to the vacuum tree mounted on the firewall. Is this bad? I just want to make sure I have it right so I don't do any damage to the engine.

[94Cobra]

The problem I see with your pcv setup is improper baffling under the breather. From what I remember from my '85 5.0 that had a carb'd pcv system is there was a breather in the front passenger VC. However, the 85 VC's had a real effective baffle built into the OEM VC. I would also suggest what someone else already said. shake the pcv make sure it rattles and there is vacuum draw from the bottom of the pcv valve when the engine is running and it is removed. I also seem to remember their should be a hose that connects the breather to the air cleaner. My 1968 Mustang shop manual does a real nice job explaining the operation of the pcv and has air flow pcv diagrams in it. My first hand experience is that aftermarket VC baffles are nowhere close to the OEM VC baffles for oil control.

[ArmyWarrant]

There are baffles now and the pcv is working. I have a holley aftermarket air cleaner and there is no place to hook the breather. I am gonna try and get a new breather, maybe this one is just to soaked with oil.

[Wolfpack Speed]

There are baffles now and the pcv is working. I have a holley aftermarket air cleaner and there is no place to hook the breather. I am gonna try and get a new breather, maybe this one is just to soaked with oil.

do you have a better picture of your breather? it doesn't look like its doing to much breathing to me!!! i think you need a breather similiar to what jivepepper posted pictures of...along with what i said earlier

[ArmyWarrant]

I don't have any other pics right now, I can get some tonight. Its one the edelbrock push in breathers that has the holes around the under side of it.

This is the one I have

http://www.partsamerica.com/ProductD...egoryCode=5001

[somethingclever]

Army Warrant,

You have excessive blow-by. Either from a clogged PCV (pull it and listen for the rattle indicating a free valve), or, like you mentioned, it’s possible the breather itself is just full of oil. The best thing to do is run a VC that is baffled around the vent hole. That alone will eliminate a lot of oil.

The description of your current system is fine. Change the VC’s, throw a new PCV in there for a 5.0, make sure the lines aren't kinked anywhere, clean the breather, and go from there.

-good luck

[ArmyWarrant]

Army Warrant,

You have excessive blow-by. Either from a clogged PCV (pull it and listen for the rattle indicating a free valve), or, like you mentioned, it’s possible the breather itself is just full of oil. The best thing to do is run a VC that is baffled around the vent hole. That alone will eliminate a lot of oil.

The description of your current system is fine. Change the VC’s, throw a new PCV in there for a 5.0, make sure the lines aren't kinked anywhere, clean the breather, and go from there.

-good luck

The Pcv Rattles and the valve covers have baffles in them. I hope it is just a soaked breather. I am gonna put a new PCV in and get a new breather and see what happens

[ArmyWarrant]

OK know it's been a while but I have since replaced the breather with a cheap one from advance and got a new pcv and the problem is gone. I looked at the old breather and the filter material that is supposed to be there was gone, there was no filter in the breather so thats why the oil was just spraying all over the valve cover.