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Procharged 502 slinging oil out breathers

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Old 06-07-2020 | 10:44 PM
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Question Procharged 502 slinging oil out breathers

So I have a 502 with pro-charger that is slinging a fair amount of oil out of the valve cover breathers.
There are no baffles on the valve covers, not enough room. Ive heard people suggest everything from baffled grommets to catch cans with breathers to vacuum pumps to my rings are bad..etc etc..

Just curious if anyone has a suggestion on how to address the issue or a set up that would work to limit this?
Also open to other things I should have checked.
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Old 06-08-2020 | 10:53 AM
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If the boat is down on power you have a lean condition with burnt up pistons. I had the same power with these issue. Once corrected there should not be a great deal of oil coming out.
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Old 06-10-2020 | 11:50 AM
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Maybe time for a leakdown test?
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Old 06-10-2020 | 01:31 PM
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Taller breather maybe or a catch can. But you should probably do a leak down test first. Sounds like a lot of crankcase pressure.
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Old 06-10-2020 | 08:14 PM
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Did it have any issues with blow by before? If not, I'd look at doing a compression test & leak down test. If you've always had that problem, I'd look into creating a positive closed type IV crankcase system. Blowers have a tendency to create more consistent cylinder blow by than do normally aspirated motors. Since you're running a centrifugal blower, you can introduce a 1" hose coming off of one of the valve cover breathers & reintroduce it into the induction airstream into the blower inlet pipe. I do this on centrifugal blower & turbo setups all the time. When the compressor spools up, it pulls a vacuum on the crankcase. And thus keep oil from blowing out from all places of the motor.
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Old 06-10-2020 | 11:22 PM
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Assuming no excessive blow by, get a puke tank.
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Old 06-11-2020 | 06:30 AM
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Having dealt with this exact issue in past, i will say at some point in your operating rpm, tune is lean or rich and hurt ring seal. On top of fact IF you still have original 4.466 bore je 700 pistons and rings, they had fairly poor ring seal to start with. Im sure a leak down test will tell you some cylinders are fairly bad. Being its middle of June and boating season is here, unless a pistons half melted and violently blowing oil out valve covers, id extend breathers up 10 or so inches, stuff the tubes with steel wool or scotch brite and run it till fall. Been there, done that! Smitty

Last edited by articfriends; 06-11-2020 at 06:34 AM.
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Old 09-15-2020 | 06:33 PM
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Originally Posted by jdhart73
So I have a 502 with pro-charger that is slinging a fair amount of oil out of the valve cover breathers.
There are no baffles on the valve covers, not enough room. Ive heard people suggest everything from baffled grommets to catch cans with breathers to vacuum pumps to my rings are bad..etc etc..

Just curious if anyone has a suggestion on how to address the issue or a set up that would work to limit this?
Also open to other things I should have checked.
Did you ever get it solved?
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Old 09-16-2020 | 11:54 AM
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boosted engines need to be oiled frequently, and even in healthy motors they vaporize oil like a mofo. Almost every motor needs an oil catch can, otherwise the back of your valves will get build up.

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Old 09-16-2020 | 12:23 PM
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The oil you use can drastically effect the need for a catch can. I added a catch can to my LT1 in my Denali and I get almost nothing after months using Amsoil. Other guys I talk to using other oil have to drain almost weekly.
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