How To Fix PCV System So Engine Doesn't Blow Oil
Jul 11, 2009 23:37:56 GMT -5
1988turbocp and stockblockturbo302 like this
Post by Stinger on Jul 11, 2009 23:37:56 GMT -5
Version 1 (Open Breather System):
The factory PCV system is barely adequate in stock form. Raise the boost, increase the airflow, and vent the valve cover like many of us do and the next thing you know, there is oil spraying out of the dipstick, valve cover, etc.
Not just any breather system will work. The catch can to be used needs to have a large inlet (1" ID or so) or two medium sized (at least 5/8" ID) inlet ports AND have the filter outlet be over an inch. This particular Moroso catch can has an internal baffle as well to keep the oil from coming out of the filter. It's got a -16AN inlet...I got it from Summit Racing, part # MOR-85475: www.summitracing.com/parts/MOR-85475/?image=large
If you want it to do an even better job of filtering oil out of the incoming air before exiting the outlet filter, add some coarse steel wool to the top area of the catch can where the inlet hose comes into the catch can.
The fitting I screwed onto the can to convert it to 1" pipe thread came from the House of Hose ( www.spokanehose.com ) for $8.22. Part number: 6506x16x16 here: spokanehose.com/product.php?id=3484 and it's cad coated steel.
So here is what I did and it seems to have completely eliminated the oil control problem:
Overall view of the system without the head/intake in the way:
Connection to stock pcv hose:
Breather location, connection to hoses:
Valve cover breather to 3/8" hose connection:
Drilled/tapped fitting to connect valve cover hose:
Completed setup:
Version 2 Closed System):
There is also a "closed" version of this system where everything stays the same as above as far as hose diameters and connections and such but instead of using a filtered catch can breather, you route the "outlet" of the catch can back into the inlet of the turbo (like the stock system) only use much bigger hose (1" ID) so it has sufficient flow out of the catch can. The turbo will draw a small vacuum on the catch can when setup this way. The only real benefit to the closed system is it should eliminate the oil smell that the breather setup sometimes produces so it may be better for a more mild daily driver type setup.
In this case, it may be easiest to use a catch can with a 1" or larger outlet port that's designed to be used with a closed system. If the can doesn't come with baffling, or if you want it to do an even better job of filtering oil out of the incoming air, add some coarse steel wool to the top area of the catch can where the inlet hoses come into the can.
The factory PCV system is barely adequate in stock form. Raise the boost, increase the airflow, and vent the valve cover like many of us do and the next thing you know, there is oil spraying out of the dipstick, valve cover, etc.
Not just any breather system will work. The catch can to be used needs to have a large inlet (1" ID or so) or two medium sized (at least 5/8" ID) inlet ports AND have the filter outlet be over an inch. This particular Moroso catch can has an internal baffle as well to keep the oil from coming out of the filter. It's got a -16AN inlet...I got it from Summit Racing, part # MOR-85475: www.summitracing.com/parts/MOR-85475/?image=large
If you want it to do an even better job of filtering oil out of the incoming air before exiting the outlet filter, add some coarse steel wool to the top area of the catch can where the inlet hose comes into the catch can.
The fitting I screwed onto the can to convert it to 1" pipe thread came from the House of Hose ( www.spokanehose.com ) for $8.22. Part number: 6506x16x16 here: spokanehose.com/product.php?id=3484 and it's cad coated steel.
So here is what I did and it seems to have completely eliminated the oil control problem:
Overall view of the system without the head/intake in the way:
Connection to stock pcv hose:
Breather location, connection to hoses:
Valve cover breather to 3/8" hose connection:
Drilled/tapped fitting to connect valve cover hose:
Completed setup:
Version 2 Closed System):
There is also a "closed" version of this system where everything stays the same as above as far as hose diameters and connections and such but instead of using a filtered catch can breather, you route the "outlet" of the catch can back into the inlet of the turbo (like the stock system) only use much bigger hose (1" ID) so it has sufficient flow out of the catch can. The turbo will draw a small vacuum on the catch can when setup this way. The only real benefit to the closed system is it should eliminate the oil smell that the breather setup sometimes produces so it may be better for a more mild daily driver type setup.
In this case, it may be easiest to use a catch can with a 1" or larger outlet port that's designed to be used with a closed system. If the can doesn't come with baffling, or if you want it to do an even better job of filtering oil out of the incoming air, add some coarse steel wool to the top area of the catch can where the inlet hoses come into the can.
