Oil Catch Can

[charger426]

Looking for some help. Just put a stock bottom (i.e. tired) 440 in and I'm getting getting a good amount of smoke (which is leaving a black mark on my hood) out of my oil breather on the drivers side valve cover. The passenger side has a PCV valve installed going to the carb. I know the best fix would be to re-ring the motor but thats not in the cards. Thinking a catch can would be a way to keep my hood from getting back. How should I hook the catch can up though?

I'm thinking the only way to make sure I don't get any oil into the intake or on my hood would be to change the breather out for another PCV valve and have both run into one side of the catch can with the other line going to the carb base. Does this sound right to anyone?

 

[AJ/FormS]

No that doesn't sound right.
Black oil doesn't sound right either.Unless it's black from soot. In which case your problem might be all in the fat carb, or the choke, and/or an overfull crankcase;which might have a high percentage of gas in the oil.
But, if the rings are really that bad, ie. pressure enough to smoke out the breather hole at idle, then there's not much hope for it. If the oil level is right, and there is no gas in the oil, I personally would not drive it. Oil is just too expensive to waste like that, for one thing.Aggravating everyone around me, for #2.Stinking up my interior, my clothes and my hair for #3. And stinking up the planet for#4. I would park it.

 

[charger426]

No that doesn't sound right.
Black oil doesn't sound right either.Unless it's black from soot. In which case your problem might be all in the fat carb, or the choke, and/or an overfull crankcase;which might have a high percentage of gas in the oil.

It is leaving a black soot spot on the hood right over the breather. I still have open headers on the car so I haven't really tuned the car past getting it to idle.

 

[AJ/FormS]

Well then,
1) check the PCV, to be sure it is actually working.
2)Maybe pull a couple of plugs and see if they are sooted up.
3)Check for gas in the oil, and make sure the crankcase has the right amount of pure oil in it
4)With the Vacuum Can disconnected,crank some idle-timing into that girl,(like 16 degrees),dial back the idle speed,reconnect the Vcan to the spark-port, and reset the mixture screws.
5)Then check the blowby at the open breather again.If it's still smoldering, I would park it.

What carb is on it?

 

[charger426]

Short of shaking it how can you check to see if a PCV is working?

Demon 850 double pumper.

 

[charger426]

Might be nothing but is the fact I'm using a more open element style K&N breather vs the more closed off looking stock style breathers maybe not catching the soot as well?

 

[AJ/FormS]

There should not be any soot at all.
The PCV has 2 tests; both with the engine running.
1)pull the valve out of the cover. Put your thumb over the hole, and then lift it off. Each time you do that, you should feel the suction change.
2)remove the valve from the hose. The engine should stall or at least the idle should dramatically change.

 

[dano]

Ditch the breather for a vacuum line from the valve cover you have the breather on to a port on the air cleaner. Like AJ said, something is not right here.

A catch can would do you no good.

850 Double pump carb sounds like way too much for a stock and possibly warn out engine. Does it have a choke?

 

[charger426]

Ditch the breather for a vacuum line from the valve cover you have the breather on to a port on the air cleaner.

No I don't



850 Double pump carb sounds like way too much for a stock and possibly warn out engine. Only thing stock is the bottom end so without knowing the rest of the motor how can you tell me about the size of my carb being wrong?

Does it have a choke? No

..

 

[charger426]

There should not be any soot at all.
The PCV has 2 tests; both with the engine running.
1)pull the valve out of the cover. Put your thumb over the hole, and then lift it off. Each time you do that, you should feel the suction change.
2)remove the valve from the hose. The engine should stall or at least the idle should dramatically change.

I will give that a shot when the weather breaks again.

 

[dano]

"Only thing stock is the bottom end so without knowing the rest of the motor how can you tell me about the size of my carb being wrong"

So what is the "rest" of your motor? The more details people can have the better your chance at getting a resolution.

 

[AJ/FormS]

The PCV system has a very small operating window. When the manifold vacuum falls the PCV draws less and less. So somewhere around 12/10 inches, it more or less becomes ineffective.What that means is that when the engine begins to work the PCV is going on vacation,at the same time that the engine is just starting to make significant blowby. So where is the pressure supposed to go? Well,on the factory system, there would be a jumper tube from the breather up to the air filter house, and all those vapors were supposed to get sucked through the top of the carb.Now, without the factory filter-house and the jumper,the breather just dumps it out onto the cover. However the ValveCover is supposed to be baffled to prevent liquid oil from getting into the breather, and the breather is supposed to have a mesh-medium inside it, to which the oil(in vapor form),is supposed to stick and then drain back,(when the PCV comes back on line) leaving only the blow by combustion gasses to pass through. It's kindof an oil-separator. Since big-cammed engines often idle at less than 10 inches of vacuum, getting a PCV to work at idle on them,can sometimes be a challenge . Your stocker, tho, should idle at 18 to 22 inches, so that should not be a problem. Unless you have installed one of those "big cams"

 

[charger426]

Running a Hughs whiplash cam. They say vacuum is supposed to be good with that cam those that.

I will say I noticed the smoke more when at idle and on the way back down from reving it up, but not while the RPMs climbed.

 

[pishta]

run breather hose up into your air cleaner base. Even with an open element, itll either draw in filtered air through your air cleaner, or it will eject the blowby into your carb inlet. having it vented to your engine bay will leave some soot. if you want to run a catch can, youd do it between the PCV and in the intake.

 

[440dartsport]

This is how I run my breathers to a catch can. No more mess.