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Turbo / oil blow by

Posted: Wed Jun 30, 2004 8:17 am
by phippsy
Have fitted a DTS kit to my 3L a while ago and all is good except that the rocker cover breather pipe that used to go to the inlet manifold, now runs to the inlet side of the turbo setup and now the turbo acts like a vacuum and seems to suck oil and oily vapour through the turbo and into the motor. Could I block off the tubo inlet side and run the rocker cover breather pipe to a sort of catch can??

Posted: Wed Jun 30, 2004 10:18 am
by GQ TROL
Just get a longer section of hose and some cable ties. Take the outlet from the rocker cover down to the chassis rail and poke it thru a convenient hole. So long as the hose doesn't become blocked, any excess oil will soak into the mud/dirt that generally accumulates in the rail. May drip oil on your driveway eventually, but not a biggy.....cos it ain't my driveway :D .

Cheers
Mitch

Re: Turbo / oil blow by

Posted: Wed Jun 30, 2004 10:24 am
by -Scott-
phippsy wrote:Have fitted a DTS kit to my 3L a while ago and all is good except that the rocker cover breather pipe that used to go to the inlet manifold, now runs to the inlet side of the turbo setup and now the turbo acts like a vacuum and seems to suck oil and oily vapour through the turbo and into the motor. Could I block off the tubo inlet side and run the rocker cover breather pipe to a sort of catch can??


That's the idea - burns the fumes rather than releasing them straight to atmosphere.

To remain legal you could direct the pipe into the side of a catch can, and run another pipe from the top of the can back to the engine intake. Theoretically the oil will collect in the bottom of the can, and the fumes continue to be burnt, as required by law.

Whilst on the subject of oil catch cans, anybody got any tips on what to make one from? I need one for my Sigma toy car because I'm sick of the oil soaking into the air cleaner element.

Cheers,

Scott

Posted: Wed Jun 30, 2004 11:40 am
by phippsy
Thought about maybe a milo tin, might work cause there's no pressure?

Posted: Wed Jun 30, 2004 11:43 am
by -Scott-
OK, I got off my backside and did a quick Google search for "Oil Catch Can" - the cheapest DIY solution appears to be a simple paper fuel filter installed in the line. I'll give it a go.

Scott

Posted: Wed Jun 30, 2004 12:50 pm
by mkpatrol
It is illegal to have any crankcase fumes exiting the engine to atmosphere. If the crankcase breather is to close to the turbo move it out further towards the air filter or into the air feilter box itself. The vacuum will not be as strong there. Most vehicles have the crankcase breather in front of the air filter so it can filter the fumes as they return to the combustion chamber. If there is excessive oil then maybe you have too much boost causing blowby in which case reduce the boost or live with it.

Posted: Wed Jun 30, 2004 1:23 pm
by phippsy
NJ SWB wrote:OK, I got off my backside and did a quick Google search for "Oil Catch Can" - the cheapest DIY solution appears to be a simple paper fuel filter installed in the line. I'll give it a go.

Scott


Might fill with residue pretty quick, but for a couple of bucks a pop, it might worth a short. Thanks for your help guys.

Posted: Wed Jun 30, 2004 9:22 pm
by J Top
Dont vent to air with out some type of filter as the hose breathes both in and out and you need to keep that dirt out.
J Top

Posted: Wed Jun 30, 2004 10:46 pm
by awill4x4
The best solution is to use a "sealed" catch can which isn't vented to the atmosphere.
The ones I have built in the past use a stainless steel "scrubber" medium inside the catch can to allow the oil to separate from the air this then drops to the bottom of the catch can. The "clean" air is then redirected back to the turbo inlet but is now minus the oil it was carrying previously.
The oil residue can then either be drained back into the sump using a tee piece in the turbo oil outlet line or drained from the catch tank using a simple tap and disposed of.
If using the latter method, it's a good idea to have a "sight gauge" on the outside of the catch can so you can see what the oil level is.
Regards Andrew.

Posted: Sat Jul 03, 2004 9:30 am
by Cliffy
The oil residue can then either be drained back into the sump using a tee piece in the turbo oil outlet line or drained from the catch tank using a simple tap and disposed of.
If using the latter method, it's a good idea to have a "sight gauge" on the outside of the catch can so you can see what the oil level is.
Regards Andrew.


Just a query on using the tee method and the sealed catch can, might you get some funky ventui effect on the catch can by the air cleaner pipe.... and draw some oil back into the catch can from the turbo dump pipe. Just a theory or am I thinking too much :?:

Posted: Sat Jul 03, 2004 10:58 pm
by awill4x4
.[Just a query on using the tee method and the sealed catch can, might you get some funky ventui effect on the catch can by the air cleaner pipe.... and draw some oil back into the catch can from the turbo dump pipe. Just a theory or am I thinking too much ]

Cliffy, no, what I do with the tee section is to actually weld a stainless 5/8" tube at a tangent to the turbo outlet tube at the sump end not high up at the turbo.
Regards Andrew.
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