Need a better PCV breather, I think.
 

I'm still working the kinks out of the engine in the sig. Today I finally realized what's been causing my oil leaks. With two 3/4" bottom vented Specter/Mr Gasket breathers installed one in each valve cover, oil starts to bubble out between the head and intake manifold once the RPM's get above idle. When I pull the breathers out, the oil stops leaking.

I'm guessing this means I need something a little more performance oriented. What kind of breather should I install that will work correctly?

Re: Need a better PCV breather, I think.
 

Those breathers should be sufficient. It sounds like crankcase pressure is coming from somewhere it shouldn't.
To have oil coming out between the head and intake sounds like a bigger problem. Have you pulled your plugs since this problem came up? Do you have the correct intake gasket installed. One that was recommended by the head manufacture or the intake man.?

Re: Need a better PCV breather, I think.
 

I have Fel-Pro intake gaskets, I think they're the ones Edelbrock calls for. I've had the plugs out many times.

Re: Need a better PCV breather, I think.
 

you need a pcv valve otherwise pressure will keep building. its normal to build crankcase pressure the pcv evacuates it. pcv in one side breather in the other

Re: Need a better PCV breather, I think.
 

It is normal to build crankcase pressure but to push oil out of the intake/head seal?


Have you retorqued your intake since you started the engine? The intake and exhaust manifold/headers bolts always need to be retorqued.

Re: Need a better PCV breather, I think.
 

Did you put thread sealer on intake manifold bolts? without a PCV it whould push the oil past the threads faster.

Re: Need a better PCV breather, I think.
 

So how do I plumb it? Do I Tee it into the brake booster line?

Yes

Yes

Re: Need a better PCV breather, I think.
 

The PCV valve needs its own vacuum source, On my 70 (i also have a holley)
i have the PCV hooked to the carb, booster is hooked to the manifold (#8 intake port) heres some PCV info

Combustion engines produce varying amounts of blow-by gases--gases containing undesirable pollutants which seep past the piston rings and into the crankcase during combustion.

SYSTEM OPERATION
The PCV system prevents blow-by gasses from entering the atmosphere by routing blow-by gases into the intake manifold through a vacuum controlled ventilating valve and a hose while allowing proper crankcase ventilation.


Blow-by gases mix with the air/fuel mixture and are burned during combustion.
When the engine is running, fresh air is drawn into the crankcase through a tube or hose connected to the air cleaner housing.
When the engine is off , the spring holds the needle valve closed to stop vapors from entering the intake manifold.

When the engine is running, manifold vacuum unseats the needle valve--allowing crankcase vapors to enter the intake manifold.

In case of a backfire in the intake manifold , the valve closes--stopping the backflow and preventing ignition of fumes in the crankcase.

During certain engine conditions more blow-by gases are created than the ventilator valve can handle. The excess is returned through the air intake tube to the air cleaner and carburetor where it is burned in the engine.

Re: Need a better PCV breather, I think.
 

never tee off the brake booster for anything. you will end up with brakes that dont work right. can you take any pictures of where its leaking from?

Re: Need a better PCV breather, I think.
 

Yeah, I forgot about that tap into the manifold. Originally, I couldn't use it because it sat right under the carb, which was in the way. But I put on a 1" spacer that will give me the room to use it.

I bought a PCV valve and fitting to tap into the intake manifold. I'll install it sometime in the next week and report back on my findings.

Re: Need a better PCV breather, I think.
 

mine was pouring oil out of the balancer seal and dipstick tube at about 5 grand
i changed breathers and it works great now
i hope you get yours figured out

Re: Need a better PCV breather, I think.
 

Mine starts doing it around 2-3K RPMs. Today would have been a beautiful day to get it fixed. Temps were in the mid 60's. But instead I worked on my wife's 38 Special getting the trigger set up for her and then tonight I went with my kid brother to see "Dances with Giant Smurfs" in 3D. If you don't mind the anti-capitalist, anti-military, Gaea-pantheistic-earth worshiping themes the visuals are well worth seeing on the big screen.

Maybe I'll get the PCV done tomorrow.

Re: Need a better PCV breather, I think.
 

wheres crosby county

Re: Need a better PCV breather, I think.
 

Hmmm, I just talked about "anti-capitalist, anti-military, Gaea-pantheistic-earth worshiping themes" in my 666th post. There's a little bit of irony in that.

Re: Need a better PCV breather, I think.
 

yeah just a little bit :lol:
im scared for you now

Re: Need a better PCV breather, I think.
 

I ate supper at the Italian restaurant on the square in Eastland about two months ago on my way to Waco. Pretty good chow.

Crosby County is the next county east of Lubbock on Hwy 82. I live about 5 mi southeast of Ralls.

Re: Need a better PCV breather, I think.
 

:devil:

Re: Need a better PCV breather, I think.
 

was the resteraunt called salvatores

:haha:

Re: Need a better PCV breather, I think.
 

Indeed it was.

Re: Need a better PCV breather, I think.
 

they have some good pizza
well if you come through again you should come by

Re: Need a better PCV breather, I think.
 

Will do.

Re: Need a better PCV breather, I think.
 

Hey all, I finally got the PCV valve installed today. And PRESTO, no oil leaks. I didn't get it done sooner because it's been pretty cold ever since the blizzard Christmas day. I still didn't take it out for a spin because our gravel driveway is still a muddy mess while all the snow drifts continue to melt off. I did let it idle for several minutes at 2-3k RPM's and am satisfied that this part of the puzzle is finished.

Re: Need a better PCV breather, I think.
 

good deal knew the pcv would get ya fixed up