looking for ideas on my Pcv system?

[chasmat2316]

Just got my new109 stroker started tonite, now I'm looking for ideas for the pcv system. Right now I have the stock set up gigged on there, but thinking of going with maybe a puke tank & maybe an electric vac pump? Anyone have pic's of this setup? Thanx!

 

[1chance]

I dont have a vac pump, but i did put a check valve for a gm vacum brake booster, between the PVC, and the TB. Works great, that alone with a piece of coke can in my valve cover (breather) no more blowing oil!!!

 

[vacuum 6]

Are you having issues with sucking oil etc? If not the stock system works great. Yes put a check valve in-line.

 

[JDEstill]

you want ideas? Here's my setup:

1. I have my PCV valve plumbed up pretty much like stock, with a check valve between the PCV and the intake to ensure no back flow when in boost.

2. I have one of those Fram clear plastic fuel filters, like what you might find on an old carb'ed car, plumbed between my PCV and the check valve. This will trap some amount of oil entrainment (though not a bunch before it gets saturated), mostly it's nice to have to visually see how much oil carryover you are getting.

3. I have open breathers on both valve covers, but I also have check valves between the breathers and the valve covers. Why you might ask? Because:
a. It lets the PCV actually pull a good vacuum on the crankcase. Last time I checked my crankcase at idle was around 6-7" Hg.
b. The low crankcase pressure means it is a lot easier for the PCV to get contaminants (water, fuel, etc) out of the oil - those things evaporate easier under a vacuum.
c. The low crankcase pressure helps eliminate oil leaks. Air trying to get into the crankcase means oil has a hard time seeping out of valve covers, rear mains, etc.
d. When cruising around the low crankcase pressure is helping ring seal. Not sure if this really helps much or not, but directionally it's the right way to go.
e. The low crankcase pressure means the actual flow through the PCV valve is greatly reduced. The closer the crankcase pressure is to the intake manifold pressure, the less flow you get through the PCV. Open breathers give you the highest flow through the PCV. To me this says you are less likely to get oil carryover than with open breathers.
f. Once you get into the boost, any blowby you do get will pass through the check valves and the breathers as normal. You might get a crankcase pressure a hair higher than if the check valves weren't there, but really the ones I used have very little restriction.

Basically, the breather check valves have a lot more advantages than disadvantages, especially on a street car. I got my fresh rebuild going last summer. First few low boost events I saw a bit of smoke out the breathers, but that was gone after the first day or two. Then I got some oil in the clear fuel filter for the next hundred or two miles or so, but once I really started giving it some boost, and the rings got seated good, that stopped. I now see very little oil in that filter.

John

 

[vacuum 6]

John,

Got pics of the valve cover check valves?

Walter

 

[chasmat2316]

anyone have pic's of vac setup with puke tank?

 

[GSTOY]

Where does one find PVC checkvalves?

Steve

 

[SSedan64]

Condensator

Not Cheap
Home
Cheap
Home Made Oil Catch Can Photo Gallery by AZ Solo at pbase.com

 

["Reaper"]

you want ideas? Here's my setup:

1. I have my PCV valve plumbed up pretty much like stock, with a check valve between the PCV and the intake to ensure no back flow when in boost.

2. I have one of those Fram clear plastic fuel filters, like what you might find on an old carb'ed car, plumbed between my PCV and the check valve. This will trap some amount of oil entrainment (though not a bunch before it gets saturated), mostly it's nice to have to visually see how much oil carryover you are getting.

3. I have open breathers on both valve covers, but I also have check valves between the breathers and the valve covers. Why you might ask? Because:
a. It lets the PCV actually pull a good vacuum on the crankcase. Last time I checked my crankcase at idle was around 6-7" Hg.
b. The low crankcase pressure means it is a lot easier for the PCV to get contaminants (water, fuel, etc) out of the oil - those things evaporate easier under a vacuum.
c. The low crankcase pressure helps eliminate oil leaks. Air trying to get into the crankcase means oil has a hard time seeping out of valve covers, rear mains, etc.
d. When cruising around the low crankcase pressure is helping ring seal. Not sure if this really helps much or not, but directionally it's the right way to go.
e. The low crankcase pressure means the actual flow through the PCV valve is greatly reduced. The closer the crankcase pressure is to the intake manifold pressure, the less flow you get through the PCV. Open breathers give you the highest flow through the PCV. To me this says you are less likely to get oil carryover than with open breathers.
f. Once you get into the boost, any blowby you do get will pass through the check valves and the breathers as normal. You might get a crankcase pressure a hair higher than if the check valves weren't there, but really the ones I used have very little restriction.

Basically, the breather check valves have a lot more advantages than disadvantages, especially on a street car. I got my fresh rebuild going last summer. First few low boost events I saw a bit of smoke out the breathers, but that was gone after the first day or two. Then I got some oil in the clear fuel filter for the next hundred or two miles or so, but once I really started giving it some boost, and the rings got seated good, that stopped. I now see very little oil in that filter.

John

can you post some pics of this?

 

[JDEstill]

Here's some pics of my valve cover check valves. They weren't real cheap, but not real expensive either. They are air pump check valves, Borg-Warner CV-39 is the one I decided to use, based on the sizes of the end connections. I think I had a little trouble finding a breather that had the right opening to mate up with the check valve, but these little K&Ns did the trick. The check valves fit a hair looser than I'd like in the valve cover grommits, but otherwise all is good.

John

 

[JDEstill]

One thing I never liked about open breathers is that they are always sucking air into the engine, except when you are in the boost. Guys clean their air filters, but how many people really thing about cleaning their breathers??? I noticed my BLMs changing fairly significantly when I sealed up the engine like this, since it was pulling so much less air through the PCV.

John

 

[chasmat2316]

anyone use a vac pump?

 

[vacuum 6]

Here's some pics of my valve cover check valves. They weren't real cheap, but not real expensive either. They are air pump check valves, Borg-Warner CV-39 is the one I decided to use, based on the sizes of the end connections. I think I had a little trouble finding a breather that had the right opening to mate up with the check valve, but these little K&Ns did the trick. The check valves fit a hair looser than I'd like in the valve cover grommits, but otherwise all is good.

John

Where did you purchase them from? Part number etc?

 

[vacuum 6]

anyone use a vac pump?

Do the search people use them.

 

[JDEstill]

Where did you purchase them from? Part number etc?

Borg-Warner CV39. I got them from my local parts store (O'Reilly's). They didn't have them at the store, but they had them at the warehouse, so I had to wait a day. Just did a price check at the O'Reilly's site, it says $24/ea. Sounds about like what I paid. There's a bunch of other check valves that are possibilities too, they just have different ends on them. If you start hunting through all the CVxx numbers, you'll see them. I went through as many as I could and decided this was the best fit, but there might be one out there that's better. The problem for me was that most of the valve cover breathers have a male connection to push into the valve cover, and I needed a female attachment I could put on the end of the check valve.

John