Projects Oil coming out the breather on my 350

Ok, I have a 010 350 that has original heads and a tri-power with Edelbrock intake. I have a breather on the passenger side and PCV on the driver side. The PCV is hooked into the middle carb. I picked the car up recently and have had 2 occasions where the car was missing like a SOB when accelerating and then it would stop. It caused one backfire out the driver side pipe. I popped the hood later that day and see oil on the hood the valve cover and leaking down the passenger side of the block towards the front and over the mechanical fuel pump. I pulled the PCV off and when the car is running it looks like steady steam pouring out of the opening like a tea kettle. I feel no pressure at all on the passenger side and does not appear to be pushing air out of the passenger side breather. I let the car run for about 30 minutes letting on and off the gas and could not get the oil to come out of the breather. I get some dark smoke out the tail pipe on occasion, but no white smoke. I checked timing and I am at about 8 degrees advanced. I plan on pulling the plugs to check them and see what color they are. What else should I be looking at? I will post up some pics of the set up in a little while.
Any help diagnosing the problem would be greatly appreciated.
Thanks

 

I would check the oil and make sure there is no gas in it and then run a cylinder leak down test.

 

Some pics of my setup

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The passenger side valve cover has a black thing stuck in a hole....is that a grommet? or a plug? or what? Normally, you'd have a grommet there, and a breather cap stuck into the grommet, to let the air in and out. Also, stock valve covers have baffles under the holes, many aftermarket covers don't have the baffles, and let oil spew out the breather

 

I had the breather removed, it is a grommet. The valve covers do not have baffles, but the grommets do.

 

Adding another breather cured mine, but the problem was compression related. What's your compression and maybe consider using covers with REAL baffles.

 

..I have a set up like yours ...the 1st thing I would do is make sure your oil does not contain gas in it,...when the fuel pump goes bad it pumps gas into the oil and this could be why you got oil on the top of the motor (over filling the motor with gas and oil, )...if the pump is ok then I would change the pcv valve....also make sure that the valve cover breather is not clogged it must let air into the motor...hope this is of help....miller

 

I have no clue what my compression is. I will look for a set of new valve covers and see if that helps. I heard that adding a PCV valve helps the oil coming out of the valve covers. A buddy of mine has a similar setup with 2 breathers and when he added the PCV it stopped the oil from coming out of the breathers.

 

Ok, tomorrow I will drain the oil and check the plugs to see how they look. I checked my oil level and it was right in the middle of the fill zone. It does smell like gas though.

 

if it smells like gas then thats a problem. Is the fuel smell really strong? does the oil feel thinner viscosity wise?

 

did you change anything to your car before it acted up? sometimes things you don't expect to be affected, get affected by new parts, just a thought

 

You need a PCV valve. It keeps a carb backfire from blowing fire back down into the crank case and from blowing oil back out the breather..... That may be where your oil came from.

 

The gas smell is strong. I am not sure how thin it is compared to how thin it should be. I have done nothing but drive the car since I bought it. I will add a fuel pump swap to the list for tomorrow and see what that gets me.

 

I see that you do have a PCV valve on one breather but where do you get the fresh air into the motor??? Normally you have a breather on one side and a PCV on the other. This allows air to come in one side and down through the crankcase and up to the PCV. Picking up all the bad fumes along the way. If you do not have a baffle under the breather or the PCV it will suck up oil every time. Plus you need to have the right PCV for the engine and cam you are running.
Good Luck.

 

I had the PCV valve on the car when I had the oil issues.

 

I personally would start with fuel pump for assurance. Hasn't happened to me but i have seen blocks that have burnt up internally because of fuel in the oil.

 

There is a breather on the passenger side. It is just not in there for the pictures.

 

By the numbers, my compression ratio is about 10.5:1, maybe a bit higher. I was getting blow by like you describe. I already had one breather and a PCV. My engine guy told me, "More compression. Add some side baffles." I did and problem solved.

 

does the block have a breather hole in the back by distributor or on the intake?

 

Im not sure what that is.

 

Cvstl has a point. If your driver's side valve cover isn't equipped with a push-in style PCV valve (it looks like it is but the picture is too small to be certain), get one.

I'd also be looking at better baffles than the perforated grommets that you have now. Metal ones for retrofit to aftermarket valve covers are available from Jeg's, etc., and would be a worthwhile upgrade.

Somewhere in the shadows of my memory lurks something about one of the pushrods being aimed directly at the vent hole on some SBC aftermarket valve covers and that the lack of internal metal baffles to deflect the oil stream can cause high oil consumption. The perforated grommets just don't get the job done and the oil is sucked into the intake through the poorly-baffled PCV valve.

In the meantime I'd temporarilty disable the PCV system by blocking the PCV valve hose and putting breathers in both vale covers. Then I'd clean up the mess and drive the car some more...and see what happens. If the car runs well and you get just a taste of blowby coming out the breathers - and no backfires, oil eruptions or other unusual events - then you can be sure that the problem is in the PCV system. What you've got now LOOKS good, but the minor changes I suggested above may be necessary to make it WORK well.

Keep us posted.

 

Blow by

 

On a side note, I remember using those little cushy things girls put in their hair, to soak up the oil. One day, I needed a new pair and got upset, when the young, female store clerk had no clue what the hell I was talking about. That was the day, I seriously sought a solution.

Please find what works and avoid the kind of embarrassment I went through.

 

You have a sealed cap on your fill tube and you need a place for the air to come in. If you do not have a road draft tube put a breather cap on your oil fill tube! Gary

 

the fill tube is a breather hole if you put a breather cap on it

 

Good eye, borracho13! If there is a PCV vent adaptor in the back of the block that is open, you need to re-route your PCV vacuum hose to it, using an in-line style PCV valve instead of the push-in style valve you have now. The resulting hole in your driver's side valve cover can receive a second breather.

The PCV vent adaptor in the back of the block indicates that you've got a tomato can-style baffle under the intake that is not being utilized. Re-routing the vacuum source to this adaptor will eliminate the tendency for oil - vaporozed or otherwise - to be drawn into the PCV system.

Clean air will be drawn into the engine block through the two valve cover breathers, while contaminated air (blowby) will be drawn out of the block through the PCV vent adaptor by engine vacuum, through your PCV valve and into the intake to be burned along with the fuel mixture.

Lets hope you've got a PCV vent adaptor. It's the best way to evacuate your block there is!

Note:

You DO NOT have to put a vent on your fill tube, nor should you. Leave it closed. The fresh air currently enters your engine through the passenger side valve cover breather. No additional air is needed.

If you re-route your PCV hose to utilize the PCV vent adapter as discussed earlier in this post, air will be drawn in through the breathers in BOTH valve covers, which again is plenty. Leave the fill tube capped as it is now.

 

Shouldn't really have anything to do with your oil problem; but the hose from the PCV valve should be hooked to the base of the center carb. Hooked up to the front carb base, as it is in your picture, may cause the front cylinders to run a little leaner than they should.

A PCV valve in one rocker cover and a vent in the other is pretty standard fare and should work OK. A lot of those aftermarket cover had provisions for a sheet metal baffle; but they always seem to be missing, or maybe never installed. Should be able to add them easily.

Sounds like you may have some other problems causing the excess crankcase pressure/blow by.

 

Also, make sure that your PCV flows the right direction...... blow through it. It should be open from the engine toward the carb, and closed when blowing back from the carb toward the engine.

I had one that was backwards. So instead of drawing the oil vapor down the carb throat, the crankcase pressure built up and blew oil out the dipstick and all over everywhere..... turned it around and all was (still is) good.

 

Don't think they made any 350's with the road-draft tube provisions in the back of the block.

 

Ok, I do not have a vent on the block near the distributor. I did look under the PCV and it is not a baffled grommet and I can see a rocker directly below it. I will put on a new fuel pump, close off the PCV system until I get new valve covers and see how that works out. I will try and get everything wrapped up tomorrow, minus the new valve covers. I will order those online. Ill post pics of the spark plugs tomorrow when I pull them.