Oil Pan breather/vent

[turbojustin]

Anyone ever tried to install a vent/breather on the oil pan to relieve some of the crankcase pressure when under boost? I know, it sounds a little f'd up. I've got a freshly rebuilt engine that likes to blow oil under boost. It started with the valve cover spacers, then I used "the right stuff" to seal those up. Now it is coming from somewhere else. Possibly the oil pan gasket...not sure yet. Anyway, it only happens under boost, and it is some serious oil. Covers the underside of the car. When it was the valve covers leaking it was super bad. Since the mystery leak happened I haven't driven it much at all. I figured if I installed a vent/breather on the upper, front part of the pan it may help.

Opinions....

 

[Ormand]

It would be hard to put a breather on the pan for the Buick engine, because it is a "deep skirt" design. The block extends down past the crankshaft centerline, so that the oil pan is shallow, and is almost full of oil. If you make a hole in the side of the pan, then oil will blow into the breather. But breathers on the valve covers should work, and do work on most cars. Why do you have so much blow by?

 

[turbojustin]

Do you think I could build a baffle around the vent/breather to keep the oil out? I'm not real sure of why it is happening. I'm just looking for a solution. I've got a very limited number of miles on the engine and haven't spent much time looking for the cause. It may be something as simple as the pan being loose. I don't even know if the leak is coming from the pan. All I know is that the starter has oil on it and so does the oil pan rail. I do have a girdle on the engine and I just realized that the pan is over full by atleast a quart...it is on the full mark of the dipstick, not below as it should be with the girdle installed. This may have something to do with it.

 

[snzuloz]

on my 86 buick i had trouble with the oil pan gasket getting squashed out with that terrible design,tried to reseal twice,finally i cleaned up the block and pan with some brakeclean and used some rightstuff without the gasket,absolutely no leaks after letting it cure overnight. the little tits on the pan don't do a lot to hold the gasket and putting anything on the gasket just makes it worse. take the oil level down maybe you just have too much windage happening.

86 Buick g.n. too many parts too list.

 

[turbojustin]

on my 86 buick i had trouble with the oil pan gasket getting squashed out with that terrible design,tried to reseal twice,finally i cleaned up the block and pan with some brakeclean and used some rightstuff without the gasket,absolutely no leaks after letting it cure overnight. the little tits on the pan don't do a lot to hold the gasket and putting anything on the gasket just makes it worse. take the oil level down maybe you just have too much windage happening.

86 Buick g.n. too many parts too list.

Was yours blowing oil or just leaking?

Currently, the engine has one of the crappy rubber gaskets and it is squashed out a bit. I have a cork replacement. Hopefully that will do the job.

P.S. I love the little tits...on my pan...and the big ones too.

 

[snzuloz]

Was yours blowing oil or just leaking?

Currently, the engine has one of the crappy rubber gaskets and it is squashed out a bit. I have a cork replacement. Hopefully that will do the job.

P.S. I love the little tits...on my pan...and the big ones too.

not sure if it was blowing it out but it sure leaked (enough to make it look bad,you know how oil spreads out so well) especially nice when it burns up on the crossover pipe. if you put the cork in put it on dry, only little bit of flexible type sealant on joints. do you have vents on your valve covers? shouldn't be pressuring up if they are open. what seals between the block and your girdle? i also had problems with pushing oil out the pcv valve on higher boost levels (i had the fel pro style intake gasket in the intake manifold without the windage tray,once replaced problem went away)

 

[turbojustin]

I now have vents on my valve covers. Originally I had no vents; they were hot air valve covers. That's when it was really bad. I'm not sure what seal is between the block and the girdle. I'm guessing rtv.

 

[CS99]

back from the dead ....lol Has anyone ever tried this? I am blowing oil past the front and rear main seals at 20 plus pounds of boost. Am looking at ways to relieve some more pressure (blow by).

 

[1KWIKSIX]

Last season I installed vented caps in both aftermarket valve covers. These were tee'd together routing them into an AMW catch can, then back into the MAF pipe pre turbo (so it was a closed loop set up similar way the factory used). I believe I used some nice chrome Mr. Gasket breathers with 3/8" hose barb outlets on them. Ran into problems with blowing oil too, but only while engine was in boost. The oil was coming out of the oil dipstick tube...pushing the dip stick up & out of it's seated position. Finally traced it back to the Mr. Gasket breathers......turned out they were defective.....I was stunned when I tried , but could not blow through the Mr. Gasket chrome vented valve cover caps. . This was causing my problems. Shame on me for not checking this first! (What a P.O.S. product).

I changed things over the winter & installed a pair of Metco's -10AN x slip in valve cover adapters with -10AN Push Fit 90's & used 5/8" heater hose teeing both valve cover vent lines together & opened up my AMW catch can to accept the larger 5/8" hose to. I initially installed some breather baffles in the valve cover grommets too, but have since removed them as they weren't req'd.
You may want to try the stepped baffled grommets in your valve covers. Just be sure to open up the slots in the rubber between the steps to ensure full breathability or you could end up with a ton of back pressure here.

Since you're blowing oil out of both your front cover seal & rear main, I'd say you've got some major crankcase pressurizing problems going on.

Must be a restriction somewhere. Take a close look & see, maybe your overlooking the obvious?

 

[vacuum 6]

Vent front cover.

 

[robzombie]

Anyone ever tried to install a vent/breather on the oil pan to relieve some of the crankcase pressure when under boost?

I have done this because of the very reasons and problems that you've stated. I did mine last year and am happy with the results.

I took the oil pan off and drilled a hole on the side as close to the pan rail as possible. I welded a 5/8" elbow to the pan and then connected and ran a tube up into the engine compartment with a breather on the end to keep contamination out and oil in.

I have never had oil blow out the breather, my fear was it would because it is so close to the oil level in the pan as stated by others in this thread. But you must realize that the oil level is lower when running as it takes time to fall back to the pan and that's why the oil pickup is so close to the bottom of the pan, so it doesn't come uncovered and starve for oil.

I get more vapor/residue out of the V/C than out of the oil pan vent. It does it's job as I have no more oil blowing out the rear seal or the front of the cover.

I run 25/26 lbs. of boost and was tired of cleaning the oil from under the car and adding half a quart after a dozen high boost runs.

 

[SS/GN]

An old trick on a BBC was to drill the fuel pump block off and put a 5/8 fitting and route it up into the wheel well area. This worked well but to be honest no better than valve cover breathers. We tested it on the dyno and found no power at the time. This was in a stock eliminator car where every single HP is worth something.

 

[SS/GN]

Finally traced it back to the Mr. Gasket breathers......turned out they were defective.....I was stunned when I tried , but could not blow through the Mr. Gasket chrome vented valve cover caps. . This was causing my problems. Shame on me for not checking this first! (What a P.O.S. product).

Dave
I have seen this and I think the Mr Gasket breathers you had were suppose to be used with a pan a vac system where vac opened them not pressure

 

[1KWIKSIX]

Could be Kevin, although there were no instructions with these that indicated so....no matter now as they were removed & quickly thrown in the dumpster long ago! LOL

thanks

dave