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Blow by with a turbo

PostPosted: Tue, 16 Nov 2021 7:56 +0000
by Mudgee mud
I have a "93" 3l 2.8 hilux, In good overall condition! It has been fitted with small C20 turbo. Oil cooled only.
No inter cooler as yet. She suffers from the typical blow of a motor at 300k +. Expected..
Fitted a hummel 200 catch can etc. 
The turbo oil return dosent seem to keep up on the gravity return line from I beleive is to much positive pressure in the crank case area.  Thus a bit of oil weeps past the slinger and ends up being sucked into the Inlet manifold.  Not a crazy amount,  but enough to think it more due to crankcase pressure than seals. 
Both my oil feed lines out and return lines have each been mated together as pairs. 
Out going oil line to the vac pump, and turbo, and both return lines mated into one. 
This part of the the two return lines together,  I think is the issue in general across the board in design hindering such. 
The larger the better re-guarding return line is obvious.  
But has anyone come up with a practical way to help sort this age old issue?
 Being going on for years now, but can't find simple remedy.  
Both of oil lines are into the block.  But I'm tempted to tig a decent sized 19mm bung into the sump for the turbos oil return line, and a secondary bung in for further earlier crank case ventilation ( linked to catch can) .
Surely This would also relieve some back pressure from top end rocker area oil return journal's.  And let oil return down without positive pressure hindering/pushing oil back up the top of the head area. 
Has this been trialled before? 

Re: Blow by with a turbo

PostPosted: Wed, 17 Nov 2021 5:25 +0000
by Mudgee mud
Oops, posting it here was a wheely bad idea! Please move to appropriate section sorry! Damn newbies!