Oil out the breather??

[dynotimeonly]

New Problem,,,
I've got a 430 that has the high dollar vented oil tank so we use a pop-up valve on the front left side valve cover breather. Came in after the feature last Saturday and the whole left side of the hood and fender(underneath) was covered with oil that blew out that breather?? Any idea's why this is happening????

-Thanks-

[mab475]

I would love to heat this explanation cause I've been trying to solve this problem for about 5 years now with no success.

[perfconn]

Only one thing can cause it,internal pressure.Question is what is causing the internal pressure? Could be anything from a wore out drysump pump to burnt pistons,wore out rings,lines being too small,lots of possibilities.

[TALON75]

What oil tank do you run? I ask because we were at the Wild West Shootout in Tucson this year and someone had the newest Peterson internally vented tank with AN fittings in the bottom where the vents are, your supposed to be able to run a filter too keep out dirt . Well they come plugged off and this guy didn't realize it and aparently doesn't run the pop off valve, It blew the tank out of the car and did quite a bit of damage to the (not a nice word)(not a nice word)(not a nice word)(not a nice word)pit and decking . I would just make sure you are getting proper venting from the tank, otherwise you may have a blowby issue .

[mab475]

Only one thing can cause it,internal pressure.Question is what is causing the internal pressure? Could be anything from a wore out drysump pump to burnt pistons,wore out rings,lines being too small,lots of possibilities.

It happens even when the engine is fresh.

[latemodel82]

I have the same issue. My motor is fresh. I was told to leave the breather in the front left and seal the back breather on the valve cover. My other question is how much pressure should my pump be putting out at max rpm? I have about 75 to 80 psi at the end of the straight away. I have 50 to 55 at idle. Is this too much?

[jason29a]

To much oil can cause it also. I don't mean putting in what you were told to put in. I mean putting in what your system needs.

[AmickRacing]

I have the same issue. My motor is fresh. I was told to leave the breather in the front left and seal the back breather on the valve cover. My other question is how much pressure should my pump be putting out at max rpm? I have about 75 to 80 psi at the end of the straight away. I have 50 to 55 at idle. Is this too much?

Don't think that's too much at all, but I sure wouldn't go any more than that.
I have a drysump system, and was running around 80-90 psi at the end of the straights. It was blowing oil out of the breather tank (vent from the tank). Lowered the pressure down to 70-80 at the end of the straights, idles around 30 or so when the motor is hot, no more oil blowing out all over the car.

I think the general rule of thumb is 10 psi per 1000 rpm you're running.

[sj valley dave]

At temp..220-230* oil pressure is 55 lb at RPM and about 22-25 at idle...5 stage dry sump...

[abe_05]

More than likely too much oil if motor is fresh. Drain oil tank and oil pan when changing oil. It sometimes hard to drain all the oil out of dry sump pans but you must do it.

[perfconn]

Latemodel82,
Somebody told you wrong.A drysump engine does not need breathers on the valve cover.A Peterson popoff valve yes,a breather no.If you run a breather on the valve cover on a drysump engine it will only allow more air to enter the system and cause the tank to blow oil.