Catch Can or Air Oil Separator???

[RioRed95GT]

Since i have done my supercharger i am getting blow by of course! I was wondering if someone could help me choose between a Jegs Oil Air Separator and a Moroso Catch Tank with a breather on top. I have heard pros and cons about each. I personal think they are each just as good. Some posts talk about using the catch can and capping of the intake. And others push the air thro the oil air separator then back into the intake! If ya guys have any info it would help. Thanks!

 

[Canary94GT]

I just crafted up an oil separator from a Husky air filter/separator I bought at home depot that I connected to the pcv valve that goes into the intake. With the new hose, hose fittings and separator, the total cost was around $27. It seems to work quite well and there is already about 1/3 teaspoon of oil in it.

That being said, if you want a separator like this Husky that is actually designed for automotive use, I'd personally go for the Jegs type of separator, mostly because I haven't heard anything about the Moroso separator and if it affects anything to have a breather at the top of it.

There are other brands of separators like the Jegs one, such as Steeda I believe.

 

[RioRed95GT]

Thanks Canary! I have seen a lot of people run the separators i just don't know if there is a benefit to the catch cans with the breathers or not? I also thought bout building my own if i go the separator route. It is easy to make one i haven't really priced any separators yet tho. Do you think that the separator puts much restriction on the air flow from the pcv valve?

 

[Canary94GT]

I've read of problems with putting additional breathers and such on these stock pcv systems, but I'm not sure of their validity, and I'm also not sure of how the Moroso separator/breather works.

I don't think the separator puts any significant restriction on the pcv valve - at least I have not heard of that being the case.

I, along with many others, have removed the little filter that is inside the separator as I believe it's unnecessary - there isn't really anything to filter since the can catches the oil. The filter also can clog up and restrict things.

 

[Last5.0]

To run a catch can with a breather the correct way you need to delete the PCV system and cap the ports on the intake that go to it then run hoses from the can to either both valve covers or one valve cover and lower intake where PCV originally was. You shouldn't mix closed/open PCV systems, either one or the other.

Then to take it one step further run a vac pump from the valve cover(s) then to the can and have the crankcase under a slight vacuum at all times.


The way a catch can with a breather works is the oil mist/vapor enters the from the side and the oil falls to the bottom and air escapes out the top breather. Some cans are baffled internally with metal slats or perforations to help pull the oil out of the mist/vapor as it goes by.

 

[revhead347]

Like Last said, you really shouldn't mix the two. The best way is to leave it as close to stock as possible which means an oil seperator. I use a Steeda one which was pretty affordable at the time and is a quick and easy install. It does collect quite a bit of oil. I think there are cheaper options out there now though.

Kurt

 

[RioRed95GT]

Ok should i just run a hose from the PCV and the valve cover to a T fitting then to a catch can and stop it there? Or should i run a hose from the PCV and the valve cover to a T fitting then to a separator than back to the intake? Witch way works better? Sorry this is kinda confusing.

 

[revhead347]

The oil seperator just goes between the pcv valve and the intake. That follows the normal flow of vent air. The factory breather just goes to the stock air filter, but if you have an aftermarket setup it may be different. You can just put a small breather on the valve cover.

Kurt

 

[Canary94GT]

If you have the stock pcv system, just install the separator between the pcv valve and the tee that connects to the intake

 

[RioRed95GT]

Ok so you guys say go with the separator route and plumb it back to the intake then. i just didn't know if it was better to do that or the Catch can and cap the intake so it wasn't using any of that air from the crank case.

 

[revhead347]

Having a PCV is better for a street car. There are a lot of corrosives that build up in the engine that can rought your engine. A PCV ensures that all that stuff gets sucked out on a regular basis.

Kurt

 

[90lxcoupe]

Like Last said, you really shouldn't mix the two. The best way is to leave it as close to stock as possible which means an oil seperator. I use a Steeda one which was pretty affordable at the time and is a quick and easy install. It does collect quite a bit of oil. I think there are cheaper options out there now though.

Kurt

Why is the stock PCV better than the catch can?

With a blower the PCV system is not up to the task of venting the crank case. The oil separator is a bandaid to a poorly engineered system that ford has never gotten right(just look at lightnings oil consumption).

Run two -12 fittings on the vlave cover to a tee and connect them to a catch can. Do it once, and do it right the first time. A plug for the PCV valve will cost you 15 bucks tops from a local machine shop. Just have one made from aluminum. It took me about 25 minutes to make one on a lathe myself.

Having a PCV is better for a street car. There are a lot of corrosives that build up in the engine that can rought your engine. A PCV ensures that all that stuff gets sucked out on a regular basis.

Kurt

Think about your logic for a second here... A PCV reintroduces these "harmful corrosives" you speak of back into the intake manifold. A catch can vents all of the unwanted gases into the bottle and they come out of the breather. This is where you want the gases to go, not back into your combustion chamber!

 

[revhead347]

It gets a lot tougher with a blower. There are a lot of diagrams on how to it on another thread. A PCV vents combustion gasses that build up in the crankcase with a cosntant flow of air. A simple breather, does not maintain that flow. It's the stagnation of the gases that causes the acidity which leads to corrosion of engine components. It's not a design flaw of a Ford either, every other car on the planet has a PCV system. Are you suggesting that almost every car made to day has a design flaw?

Kurt

 

[Last5.0]

A mechanical vac pump with a relief valve set to limit crankcase vacuum to about 8-12" is the best setup for a boosted motor. The crankcase will always have vacuum on it which helps keep seals and gaskets from blowing out from excess pressure and will also see a bit of a horsepower gain due to the vacuum on the rings

 

[RioRed95GT]

Ok guys i have a plan let me know what ya think. i am gonna keep the PCV valve for now cause i cant get to it with the kenne Bell on. I will plug it off next time i take the SC off tho. I and going to run a hose from the valve cover and PCV to a T then i will run both of them to a catch can. I think that will be the best way. I would rather keep from putting that nasty air back into the intake. Does that sound okay? Thanks for all the info tho!

 

[99FiveOh]

When I had my supercharged 95 GT it would blow oil out of the dipstick all the time. And the only thing that stopped it was putting a breather on the valve cover. I tried catch cans and separators to no avail.

A separator will stop the abundance of oil going into the intake, but it does nothing to relieve the excess pressure in the crankcase. For that, why couldn't someone just route a hose from the valve cover, through an oil separator and back to the inlet of the supercharger. It is always under a pretty strong vacuum isn't it?

I was never able to properly solve my issue before I sold the car but I'd like to see a solution for when I go boost next time.

 

[revhead347]

I don't think there is any significant vacuum at the intake to the supercharger. There is no restriction there.

Kurt

 

[90lxcoupe]

It gets a lot tougher with a blower. There are a lot of diagrams on how to it on another thread. A PCV vents combustion gasses that build up in the crankcase with a cosntant flow of air. A simple breather, does not maintain that flow. It's the stagnation of the gases that causes the acidity which leads to corrosion of engine components. It's not a design flaw of a Ford either, every other car on the planet has a PCV system. Are you suggesting that almost every car made to day has a design flaw?

Kurt

Yes, cars have design flaws all the time. Running a breather and a catch can wouldnt fly as original equipment because they smell and sometimes smoke. If the PCV system did such a good job then every major race team using blowers and turbos would be using them. I would like to see some proof of your stagnation of the gases theory. The PCV does nothing more than the breather to vent those gases. I think the OP has a good plan to get rid of the system when his blower is off and he can plug the intake. That is a good plan.

 

[revhead347]

I'm sorry, the proof is in the pudding.

Kurt

 

[90lxcoupe]

I see no proof, or pudding