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Discussion Starter #1
Boats running great, However my breather on my driver side valve cover is just spittin oil all over the cover and its runnin down my engine causin a mess. Oil level is good and oil pressure maintains good PSI...


What are my options? Puke tank, new covers, what? never tackled that issue before so i need to ask.
 

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several things can cause this among them:

1. high oil level or poor oil control...evidenced by fluctuating oil pressure at rpm, also makes the oil temperature rise suddenly when it happens

2. not enough ventilation at the valve covers...mine were fit with vents that were too small..the little blowby was pushing the oil (that is like a rainstorm in the rocker galley) out

3. blowby (bad rings)

I use bilge pump hose on the valve covers. About a foot or so. Vertical. This hose pushes in nicely to the 7/8" rubber grommet that you commonly see on the sbc valve covers. Dont pull out well over 90mph.

at the inlet i use brass screen as a splash eliminator. about 2" wrapped such that it holds to the ID of the bilge pump hose, but leaves the center clear, maybe 1/2 open in the middle...i suppose a brass 'scrubbie' would work too. Just make sure it cant fall into the rocker galley.

One hose points sort of forward, the other points sort of back and provides some PVC at speed (a PVC valve to the bottom of the carb is not safe)

Looks funny but it works. I figure the length of corrigated tube catches the splashes and vapors, "classifies" them and they run back down into the engine.
 

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Here's a pic of evac system, basically the headers create vacuum for the breathers, in return ventilates the crankcase and increases ring seal. Puke Tank is a good option also, probably cleaner in your situation.
 

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I dont think so...

What is a EVAC or a vacuum pump?
A baffle under a breather is usually just a small piece of sheetmetal under the vave cover at the breather's hole so oil doesn't have a "straight shot" out of the engine. They help a lot and a lot of aluminum valve covers have provisions for them.

EVAC has already been explained in this thread. A vacuum pump is a pump that sucks the crankcase pressure out. Some are bought as vacuum pumps and some are smog pumps.
 

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I had the same problem and was going to plumb up a puke tank but was told to try another option first to see if it would take care of the problem before I spent all the money needed to go the puke tank route. I put a small piece ( about as wide and as tall as the breather ) of a scotch brite ( green scratch pad ) down in the breather and change it out every couple days that I run the boat. It solved my problem completely and only costs me about fifty cents every other trip. Of course it will only work if your breathers don't have a large hole cut out under them. I just drilled six 5/16" holes under mine when I installed them. Or you could get a small plate and drill holes and put it inside the valve cover and bolt it on. I'd try that first to see if it works. just my $.02
 

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Discussion Starter #8
A baffle under a breather is usually just a small piece of sheetmetal under the vave cover at the breather's hole so oil doesn't have a "straight shot" out of the engine. They help a lot and a lot of aluminum valve covers have provisions for them.

EVAC has already been explained in this thread. A vacuum pump is a pump that sucks the crankcase pressure out. Some are bought as vacuum pumps and some are smog pumps.

There is a baffle. I was just not sure exactly what the heck it was called...

I had the same problem and was going to plumb up a puke tank but was told to try another option first to see if it would take care of the problem before I spent all the money needed to go the puke tank route. I put a small piece ( about as wide and as tall as the breather ) of a scotch brite ( green scratch pad ) down in the breather and change it out every couple days that I run the boat. It solved my problem completely and only costs me about fifty cents every other trip. Of course it will only work if your breathers don't have a large hole cut out under them. I just drilled six 5/16" holes under mine when I installed them. Or you could get a small plate and drill holes and put it inside the valve cover and bolt it on. I'd try that first to see if it works. just my $.02
Ill try it.
 

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One hose points sort of forward, the other points sort of back and provides some PVC at speed (a PVC valve to the bottom of the carb is not safe)

What is a PVC and why is it unsafe at speed?
 

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Positive Crankcase Ventilation

all kinds of nasty things blow by the rings, especially running nitrous.

got to get rid of that stuff someway or oil contamination happens or even a crankcase explosion could happen. In an automobile engine there is some intake manifold vacuum to help purge this stuff. WOT no vacuum...no good.

I dont like the PVC to the base of the carb because it might put oil into the combustion chamber and detonate...really nothing to do with speed.

the speed part is what PVC i get from positioning the hoses into/outof the windstream.

At one time i actually used a videocard fan...got laughed at big time, but it worked to clear some idle reversion issues i had from an exhaust/cam issue.
 

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Positive Crankcase Ventilation

all kinds of nasty things blow by the rings, especially running nitrous.

got to get rid of that stuff someway or oil contamination happens or even a crankcase explosion could happen. In an automobile engine there is some intake manifold vacuum to help purge this stuff. WOT no vacuum...no good.

I dont like the PVC to the base of the carb because it might put oil into the combustion chamber and detonate...really nothing to do with speed.

the speed part is what PVC i get from positioning the hoses into/outof the windstream.

At one time i actually used a videocard fan...got laughed at big time, but it worked to clear some idle reversion issues i had from an exhaust/cam issue.
Yea, nothing at all like putting GASOLINE in the combustion chamber. :)bulb

Motor oil has such a high flash point, you WILL NOT GET IT to ignite in a gasoline engine combustion chamber, just as you will not get diesel fuel to ignite without compressing the air it is in to something like 20X+ in order to get the ignition environment to OVER 400 degrees F.
 

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Yea, nothing at all like putting GASOLINE in the combustion chamber. :)bulb

Motor oil has such a high flash point, you WILL NOT GET IT to ignite in a gasoline engine combustion chamber, just as you will not get diesel fuel to ignite without compressing the air it is in to something like 20X+ in order to get the ignition environment to OVER 400 degrees F.

YOu allways got to ruin it with science and facts and shit.. Geesh!!:(:(



However on a serious note i do have a PCV on my boat. should i remove that and plug the carb hole? I didnt even think that if oil was coming out of my breather it might also be flinging into my engine...
 

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YOu allways got to ruin it with science and facts and shit.. Geesh!!:(:(



However on a serious note i do have a PCV on my boat. should i remove that and plug the carb hole? I didnt even think that if oil was coming out of my breather it might also be flinging into my engine...
LowriderSS Is my Hero! He is the Peter Jennings Of the forums
 

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Yea, nothing at all like putting GASOLINE in the combustion chamber. :)bulb

Motor oil has such a high flash point, you WILL NOT GET IT to ignite in a gasoline engine combustion chamber, just as you will not get diesel fuel to ignite without compressing the air it is in to something like 20X+ in order to get the ignition environment to OVER 400 degrees F.
and just what temperature do you think combustion is taking place at?
and just what temperature do you think the cylinder walls run at?
and just what is the pressure just after the ignition as the cylinder approaches TDC
and just how much oxygen is there left to burn at TDC?

any oil suspended in the combustion chamber will cause detonation, if you are on the verge anyway.

oil mixed with gasoline will cause destructive detonation in very small amounts, if the engine is being run at a high capacity. Blower seal leaks have been known to detonate engine. I have had valve guide seals cause detonation...no smoke just detonation.

I wont run my PCV into the base of the carb on an engine i know will be run hard or with nitrous.

I had oil blowing out all over the boat
I dont have oil blowing out all over the boat (any more)
I found some reasons why
I corrected the problem cheep and effectivly.
 

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Positive Crankcase Ventilation

all kinds of nasty things blow by the rings, especially running nitrous.

got to get rid of that stuff someway or oil contamination happens or even a crankcase explosion could happen. In an automobile engine there is some intake manifold vacuum to help purge this stuff. WOT no vacuum...no good.

I dont like the PVC to the base of the carb because it might put oil into the combustion chamber and detonate...really nothing to do with speed.

the speed part is what PVC i get from positioning the hoses into/outof the windstream.

At one time i actually used a videocard fan...got laughed at big time, but it worked to clear some idle reversion issues i had from an exhaust/cam issue.

I know what a PCV is, but was unsure about the PVC. I believe the PVC is what is used for plumbing in a house:)hand
 
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