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oil being sucked threw the pcv valve on my 350 sb..

13K views 22 replies 9 participants last post by  rifraf 
#1 ·
Its been less then two months sence i have changed my oil in my 350 sb, my 350 has a high volume oil pump. I checked my oil and it was 2 qurats low.. the engine has less then 200 miles on it sence it has been rebuilt.. i have no oil leaks,no oil in the water,it dont smoke when it is ideling or if i give it gas..
but when i checked my pcv valve ,it has oil on the hose side and in the hose it is wet with oil.going to the carb. i have no blow by, if i take the breather out of the pasenger side valve cover and put a peice of paper over the hole with it running it tries to suck it in.
Im guessing when i get down on it,with my high volume oil pump it is putting alot of oil into the valve cover and its being sucked out by the pvc valve. am i right??? and if i turn the valve cover around will this help my problem or fix it.???? .. my valve covers has baffles in them..look under my others threads on tunnelram,or robbie on my specs on motor if you need them, or click on the link under my picture to see the valve cover.. any advice would be great.
Robbie:thumbup:
 
#2 ·
If there is that much oil in the valve covers and some in the push rod valley and the filter is full, how much is left in the pan?

Troy

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If you don't make mistakes. your not doing anything.

69 ss rs full custom camaro 98 ISCA grandchampion
69 ss rs bb camaro wifes driver
66 Elcamino 350/all dz parts,ac,windows,loaded,my driver
69 ss chevelle bb conv.fresh frame off
26 T sedan street rod
 
#4 ·
troy-curt said:
If there is that much oil in the valve covers and some in the push rod valley and the filter is full, how much is left in the pan?

Troy i was just guessing

__________________
If you don't make mistakes. your not doing anything.

69 ss rs full custom camaro 98 ISCA grandchampion
69 ss rs bb camaro wifes driver
66 Elcamino 350/all dz parts,ac,windows,loaded,my driver
69 ss chevelle bb conv.fresh frame off
26 T sedan street rod
 
#5 ·
Just a suggestion,they make a baffled canister that I have used for poor baffles in the past,they are intended for non baffled covers,another slick thing is to put a hole under your plenum with a baffle canister poked in it (with a valve cover grommet) and use a threaded PVC in the plenum,then run a breather on each cover,looks tight and clean,and works good. Be sure your not pumping all your oil up top,don't want to empty that pan.
 
#6 ·
Some aftermarket valve covers use blind grommets with a slit cut into the bottom of them as a "PVC baffle". These are great for directing oil into the PCV system. These have caused more than a few engines to be condemned as "oil burners". The stock type of baffle is still among the best as long as they don't interfere with the rockers if they've been changed to full rollers.

tom
 
#9 ·
Yes my motor is a complete roller motor,roller lifters,roller rockers
i notice also that my oil presure has droped about 5pds, it was running around 35-40 ( thats with it hot and in gear) now it drops to around 30 but it might have something to do with the oil too, i was running racing oil,20w-50w i had to add 15-40w oil about two qurats,so i know i thined it out.
 
#14 ·
Yes,it would work,but your leaving an area of vapor not circulating and if I could avoid that I would. The other reason I suggested twin breathers is if the dual quad is being run at the range it likes,you create more blowby,possibly more than one breather can handle,there is no harm in having too much ventilation,but plenty without.
 
#16 · (Edited)
You always have some amount of blow by,even at an idle,thing is its so minimal,at least it should be,that you sometimes cant tell at all. As your rpms increase your rings start to dance,or skip more causing the seal to become less effective,also as you start building more power vs load the gases are more apt to escape or be forced into the crankcase,so----yes.

Another thing,as you get the rpms up,your making a lot more oil particulate from all the rocker arm action creating a real need for a premo baffle,thats another reason I prefer the lifter valley for a source to draw from.
 
#18 ·
True, there's blow-by most of the time. Luckily the PCV system pulls a stronger vacuum during normal loads. Try this. With the engine running, leave the PCV in place but remove your breather hose/filter from the rocker cover and place the palm of your hand over the rocker cover breather hose. All being well you would feel vacuum building. Then when you release your hand you should hear a whoosh as the air rushes into the crankcase caused by the vacuum built up. This is a good test for the engine's seals and a basic check for minimal blow-by.
 
#23 ·
Well,this is sort of like who has the best mouse trap,so heres a couple of mine. If you don't mind pulling the intake off to drill a hole,I would go right under where the pvc hose is plumbed in now since its an empty cavity and its higher than the rest of the intake and that would lean to better oil shielding,not to mention it would look clean and tight,if you choose that location a stock GM rear breather baffle(early 60s sb) can be used and hidden underneath,careful to drill it for an interference fit,then shove a rubber grommet in from the top side,poke your pvc in and go strait up to a hose fitting,loose your angled one. The other way is to come off the front. Im not sure if yours has it,but it looks like an old weind I had,if its the same,theres an access hole with a plug for an oil fill tube right next to the thermostat,pop that plug and put a baffle in that location,as far as your pvc goes,there are many designs from threaded,push in,to inline. all I can suggest is find a setup that looks clean and does the job. Ive had much better luck in these areas than the valve covers for a draw sorce on high rpm setups,hope that helps,sorry for the time gap.
 
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