Have a 327 SBC is mild no more than 350 ponies..on the e-way at 75 or more she seems to start blowing some oil past the filler breather. I cleaned the PCV valve with some injector cleaner but its still doing it..Maybe it isnt working? (PCV) or something else? Usually the 327 has the filler tube but mine doesnt have that anymore sisnce there is an edelbrock alum. inake on it now..so the breather/ filler is the only place to put oil in when it comes time for an oil change..Any one out there with suggestions as to what i should try?
Had the same problem. You don't need both the pcv and breather. Put a solid grommet in under the breather so it can't blow through. Using both also causes a vac. leak in the crankcase and basically defeats the purpose of the pcv.
Come to Think of it i ran into this problem in a BB Blue Oval engine i once had in a Jet Boat..and thats exactly what i did there too..i plugged the breather and made it into just a filler..keep the PCV and the problem went away..Thanks RR
Is there a baffle in the valve cover where the breather plugs in? OR is there a baffle in the breather itself? THere has to be a baffle to separate the oil from the air coming out of the breather. Actually with a pcv valve there should only be air entering the breather and not exiting it. It's possible your problem is excessive blowby due to worn out or broken rings. A leak down test may be in order.
Naww no blow by..runs too stong and went thru it too much on the build..and yes both the breather and valve covers have a baffel in them..its not a tremendous ammount of oil..and it oly happens when im jammin down the e-way at 75 + doesnt do it in the city at all. Its just enough oil to piss ya off..like 5. 6 o7 dots of oil spred out across the left valve cover..im going to try pluggin it off like i did on my 460 and like Rich mentioned and see how it goes..Thanks
I stuff my breathers with lawnmower type foam air filter material. It cuts down a bit on the oil blowing out and making a mess.
I like to set up the PVC in one valve cover hooked to va***n and then a tube from the other valve cover to the air cleaner base. This creates a closed loop for outside air to be pulled into the engine on the one side and ventilated into the fuel stream on the other side. It's clean and it stops all the little seepage leaks around valve cover gaskets, timing covers, etc. Chrlie
Charlie ..as i remember the proform dress up kit i bought did have a provision to do exactly as you speek..although the breather that they included didnt have a way to put the hose from the air cleaner..now that you mention it my Mo-Par 68 Chargers 440 has what you are talking about..sounds like good advice..will definetly look into the possibilities of doing that...mmmm now to find out what i did with those parts i bought over a year ago...dam!!
Do you have to have a tube from the valve cover to the air cleaner base, or can you just have a PCV on one side and an oil fill plug (no breather) on the other valve cover? Right now I have a breather with a vent tube on it (sealed on the bottom, not like a standard breather) and I have a PCV mounted in-line between this breather tube and my carb base. On the other side I have a standard breather, but according to a post above, that's defeating the usefulness of the PCV...and I should use a plug in that cover instead of a breather... I just don't want to create excess pressure by putting an oil fill plug in the other valve cover instead of the breather, and theres no way I can run a tube from the valve cover to the base of the air cleaner. would it be ok to plug one cover completely and run a PCV in the other, with nothing else?
PCV in one valve cover, breather or hose to air cleaner in the other valve cover. For the Positive Cranckcase Ventilation system to work right you should have a place for it to draw air in. If you seal the air inlet side the system can't work as intended.
No, you should have a hose to the air cleaner to work right.BUT... most times when theres a problem with oil blowing outs its usually a ****ty baffle in the breather cap.If you look at it you'll probably just see some holes in the bottom side with nothin in them( no foam) a common, quick cure is to put a black, fat, Scunchie(?) under the breather if its a dome type!!I have a tube in the front of my manifold & had that problem I solved it by putting in a valve cover breather also. I do have a baffle in the tube too, but it didn't help at first. the "new" breathers are really made ****ty, especially the Mr. gasket ones or any from a chain parts store.I try to find NOS ones at swap meets. JimV
I am trying something..here it goes..I am going to try this, I am useing the breather off my 440. it has a provision for a 5/8" hose i put the breather inlet to the bottom of my air cleaner base..Im going to hook them up tonight when i get home and take a highspeed p*** down my local freeway..(75 ..78 MPH) and see if this cures the problem..hope the ***** dont puke it up into my air cleaner..I'll be pissed than..lol. this should do the trick and prove the crankcase ventalation issue. or Not? sounds stable to me its the way my Mopar is set up..should work. any chevy pureist want to ***** at me for using a Mopar breather on my Bow Tie?
Pluging the hole that the breather goes in can cause the pcv system to pull a vacuum in the crank case and actually help pull oil by rings and valve seals. Like bigdog said, plugging the breather defeats the purpose of the system.
The pVC IN ONE SIDE AND THE BREATHER IN THE OTHER SHOULD BE FINE oops caps lock again even with out the hose. If you have after market valve covers and no baffles in em pull em and put some in. Small block chebys have way too much oil in the overhead to begin with then at high speeds its really pumping it up there. The other alternative is the rubber gromets that have baffleing in them. If the baffles dont stop it then I dont care how good it runs you have blowby and thats forceing the oil out of the engine with crank case pressure. Dave
I've tried the deal of a v.c. breather instead of the hose to the air cleaner base and it was always "wet". The hose seems to work better. I have a pal who recently plumbed his new engine with a PVC on each side - the vacuum evacuated the block cavities and started pulling air in through the rear main seal. It made a hell of a shrieking noise like steel against steel. Charlie
went and added the breather with the hose to bottom of air cleaner..looks ok..just waiting to get it out on the e-way for an 80 mile an hour 35 mile ride to see for sure ..so far in the city no problems
i think the breather with a hose attached that goes to your air cleaner is not a breather at all and just a way of getting around your valve cover not having an internal baffle, if it really was a breather it would have holes on the under side and the ones i have seen with a hose attached do not. i`m going to put this setup on my 250 as now i have a breather and a pvc and it leaks oil out of every gasket, i know i have lots of blowby but i`m hoping not to pull this engine for awhile yet.
If its the 283 or 327 older than 1966 the beather on the back of the motor ,with out a pvc will work fine, but the can under the intake needs to be in there. I had forgot to put the can in mine and it blows oil like crazy. 1966 to 196? are the same setup as a 350 or 400
ok I did it..the breather with the hose to the aircleaner base did the trick..now my system is complete..PCV in the right bank..breather to aircleaner in the left bank..no oil anywhere..went for a nice 90 mph sprint up the e-way..crused at 75 for a while..did some back roads driving between 55 and 45..from what i can tell..this problem is solved..thanks guys..if it changes i will re-post kill this thread
I've got a reprint of an old hotrod magazine article. It shows how to cut 3 slits in your fill tube with a cut-off disk and then weld in flat sheet metal in the slits so the fill tube is baffled. They were using the ribbed corvette valve covers and they had vents coming out the front of them with like 1/4 npt attachments. the two tubes ran to a resevoir mounted on the fender well with what looks like a filler tube vent on it and a drain plug on it's underside. I ***umed the resevoir had cotton in it or some other material. I'll see if i can't scan the article and psot it later tonight. damn it...need to read better.... " no filler tube"... but thought i'd post the picture from the article anyway...here goes.
dont have a filler tube any more..when i put the edelbrock alum. intake on it did away with that..besides that mopar breather to the aircleaner base did the trick
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