Go Back  Offshoreonly.com > Technical > General Q & A
Procharged 502 slinging oil out breathers >

Procharged 502 slinging oil out breathers


Procharged 502 slinging oil out breathers

Old 06-07-2020, 10:44 PM
Thread Starter
Join Date: Apr 2020
Posts: 3
Likes: 0
Received 0 Likes on 0 Posts
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.
jdhart73 is offline  
Old 06-08-2020, 10:53 AM
Join Date: Nov 2000
Location: PA USA
Posts: 1,461
Likes: 0
Received 0 Likes on 0 Posts

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.
baja27 is offline  
Old 06-10-2020, 11:50 AM
Join Date: Dec 2002
Location: cincinnati, ohio
Posts: 610
Received 1 Like on 1 Post

Maybe time for a leakdown test?
bobkatz is offline  
The following users liked this post:
PA.WOODCHUCK (06-10-2020)
Old 06-10-2020, 01:31 PM
Join Date: Sep 2013
Location: Wisconsin
Posts: 1,296
Received 29 Likes on 16 Posts

Taller breather maybe or a catch can. But you should probably do a leak down test first. Sounds like a lot of crankcase pressure.
IGetWet is offline  
The following users liked this post:
mike tkach (06-11-2020)
Old 06-10-2020, 08:14 PM
Join Date: Jun 2020
Posts: 11
Received 2 Likes on 2 Posts

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.
jhonster is offline  
The following users liked this post:
articfriends (06-11-2020)
Old 06-10-2020, 11:22 PM
Charter Member # 55
Charter Member
Griff's Avatar
Join Date: Oct 2000
Location: Omaha
Posts: 17,646
Received 155 Likes on 89 Posts

Assuming no excessive blow by, get a puke tank.
Griff is offline  
Old 06-11-2020, 06:30 AM
Platinum Member
Platinum Member
iTrader: (1)
articfriends's Avatar
Join Date: Jun 2004
Location: Frankenmuth
Posts: 6,464
Received 40 Likes on 26 Posts

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.
articfriends is offline  
The following users liked this post:
mike tkach (06-11-2020)

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

OSO Sponsor
OSO Advertiser
OSO Advertiser

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service - Do Not Sell My Personal Information

Copyright © 2018 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.

OSO Advertiser