Originally Posted by Rodinator1234

Yes I run a billet spectilties catch can as far as a reduction in oil consumption I guess it does in a sence. I use it only to keep oil out of the intake. The oil I catch I just pour back in the motor so in a sence I guess it reduces consumption.

Originally Posted by DVS LT1

Excellent point: I did NOT use the brass filter that came in my husky separator. You don't need to "filter" anything coming through - you simply want to catch any oil/residue from getting back into the intake. My setup has no problems separating the fluid. The filter is not necessary. Also, that brass filter is so fine (I mean extremely fine) I was worried it would actually affect vacuum.

My separator had a little plastic valve at the bottom which is used to release and drain any fluid when needed. However, I found that even with the valve closed it was not air tight. So rather than losing vacuum or having oil drip from the bottom I used some epoxy and sealed the plastic base/valve from the inside and the outside. That entire plastic catch basin was now 100% air tight. Works like a charm.

Originally Posted by quik95lt1

i run a vacuum pump now but if not run your pcv hose to the top of a sealed catch can and run your valve cover lines into the side the can gets a vacuum pulled in it the vapors get pulled out top and back into intake and the oil falls to the bottom.......with a cammed car bigger hose -8 or -10an helps to move extra volume to make up for the lack of vacuum......

Originally Posted by DVS LT1

If you are wanting to install a catch can, your diagram is wrong. Take a look at all the pics in this thread (3+ pages) and you will have a clear picture of what to install and where.

For reference, the flow direction of the PCV system is 1) exiting through the driver side hole/rubber grommet at the side of the intake, 2) traveling towards the front of the car, 3) turning around and entering the very front of the intake directly below the TB. When we're talking actual PCV the system is routed entirely on the driver's side of the engine and no valve covers are involved. The system gets its opening (to outside air) on the passenger side (in stock setup): through the air feeder hose from the TB to the passenger side valve cover, OR from a valve cover breather if that method is replaced.

Just look at all the pics and you should get it.

Originally Posted by DVS LT1

Here.

A catch can (if that's what you want) can go anywhere between point A and B. Because the stock hose is metal, you need to remove and replace with some flex hose. It can be routed anywhere you want as long as it gets from A to B.

Originally Posted by DVS LT1

I can't quite follow what you are trying to do - connect a vacuum pump to a catch can? Do you understand what the PCV system does and how? IF yes, skip to next paragraph... The positive crankcase ventilation system is designed to purge the crankcase (inside of the motor) of built up pressure. When an engine runs, the crankcase (everything underneath the pistons) tends to get pressurized from exhaust, unburned fuel, etc. that may squeeze past the piston rings. If the inside of an engine was truly "sealed" that pressure could accumulate and your gaskets and seals would soon blow from the inside out. So the PCV system is there to ventilate that pressure *as well as pull out any oil mist or fuel vapor that can lurk inside the crankcase. This is where catch cans come in handy (more on this later). You could say the system starts at the metal nozzle at the very front of the intake manifold (point "B" on that pic I shared). That nozzle leads to a little chamber inside the intake which is open up to the main plenum above (directly behind your TB blades). The PCV system uses the engines own vacuum to create that suction necessary for circulation. So from this point the suction effect draws out all that crankcase pressure and vapor via a path which winds up through a separate (enclosed) chamber in the intake manifold, out that side opening (point "A") and down through that metal hose. The pressure/vapor gets sucked up into that nozzle and up into the main intake plenum where it joins the air coming in through the TB and flows down the runners and on its way to combustion.

The stock PCV system usually works just fine by using the engines own vacuum to circulate the system. Some engines produce more crankcase oil/fuel vapor than others and thus all that crap the PCV system pulls out gets spewed back into the engine. This is why intakes can look so dirty behind the throttle blades. The purpose of a catch can is to trap the liquid/vapor and stop it from getting sucked back into the intake. The vapor flows into the catch can which separates and holds the liquid while allowing only the 'air' (lets call it) back into the engine. A vacuum pump, as quick95 described having, is a machine, usually electric I think (possibly belt driven) which literally powers the vacuuming effect on the crankcase. This application is for guys who have a LOT of internal pressure going on in their engine and/or poor vacuum whereby the engines own vacuum level isn't sufficient to purge the crankcase enough on its own. Most LT1 guys do NOT need a vacuum pump; again, your engine's own vacuum is enough to effectively maintain the PCV system.

As far as valve covers go, this is usually where the PCV system opens up to the outside environment (providing the inlet of air and end point - depending how you look at it lol - of the system). The stock system has a tube that comes from the TB where a small amount of air on its way through the TB blades gets diverted and sent through this little breather tube into the side of the passenger valve cover. As the engine vacuum is pulling all that bad vapor out of the crankcase below, its also drawing in this fresh air through the inside of the passenger valve cover down through the oil drain back holes in the heads and into the crankcase. Some guys decide to eliminate the stock air feeder setup and instead add a valve breather (to either or both valve covers - BTW if you were to cap the valve covers completely you would kill the system bc it wouldn't be able to circulate). SO, If you are talking/wanting to add a catch can I understand how either of the valve covers comes into play... Leave the breather system stock (via TB tube) or cap it and add a breather. I don't see how/why either valve cover would end up getting connected to a catch can (?)

Note: some dudes decide to block off their PCV system entirely, relying on breathers in the valve covers to vent the system. This isn't a popular route because their is no "positive" ventilation happening anymore. You are letting the engine vent its internal pressure/vapor to the outside on its own. With the stock PCV system and/or a vacuum pump setup, there is an active vacuum SUCKING the pressure and vapor out of the crankcase. All a catch can is doing is separating the fluids from the air on its way back into the engine.

Originally Posted by DVS LT1

However you want. I've seen guys run a hose from point A (PCV valve connected to grommet), ran it to the back of the engine bay, tied their catch can/separator underneath the plastic windshield base (under the wipers), then ran the hose all the way toward the front of the car and around into the intake at point B. As long as you are connecting point A to B you are doing the same thing as the stock system does. The catch basin can go anywhere in between. Just be sure to remember the flow always goes towards the front of the intake.

Originally Posted by Rob94hawk

Originally Posted by 93M6Formula

That is how my '93 intake works also. The rubber grommet holds the PCV valve and then a rubber hose comes off of that and makes a sharp "U" shape into the port right next to it.
.

Originally Posted by DVS LT1

That diagram is a bit confusing - I'd need to see how the system is setup/routed in stock form (with tubes/wires). Basically however it is setup now you want to duplicate, except replace hard metal line(s) with hose and add the catch can.

Originally Posted by DVS LT1

I can't quite follow what you are trying to do - connect a vacuum pump to a catch can? Do you understand what the PCV system does and how? IF yes, skip to next paragraph... The positive crankcase ventilation system is designed to purge the crankcase (inside of the motor) of built up pressure. When an engine runs, the crankcase (everything underneath the pistons) tends to get pressurized from exhaust, unburned fuel, etc. that may squeeze past the piston rings. If the inside of an engine was truly "sealed" that pressure could accumulate and your gaskets and seals would soon blow from the inside out. So the PCV system is there to ventilate that pressure *as well as pull out any oil mist or fuel vapor that can lurk inside the crankcase. This is where catch cans come in handy (more on this later). You could say the system starts at the metal nozzle at the very front of the intake manifold (point "B" on that pic I shared). That nozzle leads to a little chamber inside the intake which is open up to the main plenum above (directly behind your TB blades). The PCV system uses the engines own vacuum to create that suction necessary for circulation. So from this point the suction effect draws out all that crankcase pressure and vapor via a path which winds up through a separate (enclosed) chamber in the intake manifold, out that side opening (point "A") and down through that metal hose. The pressure/vapor gets sucked up into that nozzle and up into the main intake plenum where it joins the air coming in through the TB and flows down the runners and on its way to combustion.

The stock PCV system usually works just fine by using the engines own vacuum to circulate the system. Some engines produce more crankcase oil/fuel vapor than others and thus all that crap the PCV system pulls out gets spewed back into the engine. This is why intakes can look so dirty behind the throttle blades. The purpose of a catch can is to trap the liquid/vapor and stop it from getting sucked back into the intake. The vapor flows into the catch can which separates and holds the liquid while allowing only the 'air' (lets call it) back into the engine. A vacuum pump, as quick95 described having, is a machine, usually electric I think (possibly belt driven) which literally powers the vacuuming effect on the crankcase. This application is for guys who have a LOT of internal pressure going on in their engine and/or poor vacuum whereby the engines own vacuum level isn't sufficient to purge the crankcase enough on its own. Most LT1 guys do NOT need a vacuum pump; again, your engine's own vacuum is enough to effectively maintain the PCV system.

As far as valve covers go, this is usually where the PCV system opens up to the outside environment (providing the inlet of air and end point - depending how you look at it lol - of the system). The stock system has a tube that comes from the TB where a small amount of air on its way through the TB blades gets diverted and sent through this little breather tube into the side of the passenger valve cover. As the engine vacuum is pulling all that bad vapor out of the crankcase below, its also drawing in this fresh air through the inside of the passenger valve cover down through the oil drain back holes in the heads and into the crankcase. Some guys decide to eliminate the stock air feeder setup and instead add a valve breather (to either or both valve covers - BTW if you were to cap the valve covers completely you would kill the system bc it wouldn't be able to circulate). SO, If you are talking/wanting to add a catch can I understand how either of the valve covers comes into play... Leave the breather system stock (via TB tube) or cap it and add a breather. I don't see how/why either valve cover would end up getting connected to a catch can (?)

Note: some dudes decide to block off their PCV system entirely, relying on breathers in the valve covers to vent the system. This isn't a popular route because their is no "positive" ventilation happening anymore. You are letting the engine vent its internal pressure/vapor to the outside on its own. With the stock PCV system and/or a vacuum pump setup, there is an active vacuum SUCKING the pressure and vapor out of the crankcase. All a catch can is doing is separating the fluids from the air on its way back into the engine.

Originally Posted by smitty2919

Added length I would think would only help. It would allow the air/oil mixture to cool and condense. Just make sure that the catch can is the lowest point of the system so any oil that pools in the line can "drain" into the catch can.

We are not talking A LOT of oil, but from a design/functional standpoint having the can lower than the ports on the motor only make sense.