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1999 - Oil Catch Can - explain oil catch cans to me?

1981 Views 15 Replies 11 Participants Last post by  Dantrax
Would someone please explain oil catch cans to me? I see the term being used and have seen them being advertised but don't quite understand the necessity or usage of them. Is this something used on the turbo cars and actually functional or more just a case of selling an idea that also has some bling and doesn't really do anything on non-race cars? :confused:
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They keep oil out of your intercooler,throttle body,intake manifold & so on.They are good to have.


joe r
Quoted from Perrin's website.

OIL CATCH CAN
Blow-by is a constant problem with any turbocharged engine. While a normal byproduct of the combustion process if it isn’t contained outside the engine it will collect and gum up the valve train, turbo and most importantly the intercooler and plumbing. When this occurs it reduces the thermal efficiency of the intercooler, thus losing power and performance. With our cleverly designed and easy to install silicone catch can you can control this problem. Available in red, blue or black to compliment any engine bay. Universally designed to work with all turbocharged applications.

COOLANT OVERFLOW TANK
Replace your ugly OEM coolant overflow tank with a PERRIN catch can /coolant over flow tank. The PERRIN Catch Can doubles as a coolant overflow tank that can change the appearance of your engine bay. Included with the kit are numerous mounting brackets that allow you to install the tank virtually anywhere. This can also add clearance to aftermarket intercooler piping, on kits that don’t include them. The sight tube on the side shows how much coolant is in the overflow tank. Available in red, blue or black to compliment any engine bay. Universally designed to work with nearly all coolant systems.

Oil Catch Can
Oil catch cans and the idea have been around forever. We have taken this idea and added style and an innovative design that fits anyone’s desires. Because our Catch can uses Silicone for the body, and machined aluminum caps for the top and bottom, it can be mounted anywhere your mind desires.

Why do I need an Oil Catch Can?
Lets look at your engine for a moment. Every engine during the normal combustion process, has blow-by. Engine Blow-by is excess combustion gases that leak by the piston rings and escape into the engine crankcase. During each compression or power stroke of a normal engine cycle, a very small amount of gases leak by the piston rings. This happens because the piston rings do not create a perfect seal. This Blow-by of gases is very small, but the higher the RPM and the more pistons, the more the blow-by starts to create pressure in the crank.

This pressure needs to be released, and is done so by crank case vents. Because manufactures have to keep environmental issues in mind, these gases can’t just be vented to atmosphere. So the OEM’s vent these gases back to the intake system to be re-burned. This all sounds good, but Blow by is nasty stuff!

Engine blow-by contains gases and oil from the crankcase. The gases aren’t really a problem, but the oil is. This oily mess coats everything in its path as it makes it way back to the combustion chamber. This nasty oil mess gets into the turbo, then boost tubes, then intercooler, into the intake manifold, and finally back into the engine. As the oil creeps in between couplers and boost tubes, it can cause the connection pop off under boost. This oil then gets into the intercooler coating all the cooling fins. This greatly effects the ability of the intercooler to cool, and the efficiency of it will drop! This will cause a huge loss in power and can cause detonation. The last place this oily mess sees before the combustion chamber is the intake valves. Because of the temp differences and the oil impacting them, the oil will start to build up and form sludge. This adds up over time, and can cause many other problems, and hurt performance.

From this you can see, blow-by is bad, and it needs to be delt with.

How Does the Oil Catch can work?
As describe above the oily mess goes from the crank case to the intake system, and generally through a rubber hose. An oil catch can simply intersects the hose and the oily mess before it reaches the intake system. The top of our Oil Catch Can has 2 fittings, one in and one out. The oily mess goes in the can, gets trapped because of either the media inside the can, or from the change in direction, or from a change in temp. This separated the good from the bad, and collects the bad.

As the fluid fills the can, the end user can use the sight tube on the side of the can to determine when to drain it.

Why would I need more than one Catch Can?

Because engines have more than one crank case vent, and or more than one type of crank case vent, they can use more than one catch can. For instance on a Subaru WRX, there is a crank case vent, valve cover vent and PCV hose. All of these vents do different things at different states of engine load, and in turn, all could use a separate catch can.
Coolant Over Flow Tank

Think of this as an added bonus. Because of our unique design, and mounting system, we added a few more parts to allow the end user to use the tank in many other ways other than to catch oil. Included with the kit are instructions how to replace your existing coolant overflow tank with a PERRIN Coolant Over Flow Tank. Same as the Oil Catch Can, we include brackets, spacers, bolts, hoses, and other things to remove the ugly OEM Coolant tank.

Or let your imagination run wild, and replace any number of other tanks in your engine bay.
Perrin Performance - Oil Catch Can/Overflow Tank
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If you pull of the vent hose, usually attached to the intake to your TMIC & it has oil on it. Your intercooler's innards are getting coated with oil. The oily suraces will collect any dirt that gets past the air filter... not a good thing!:(

I'm not sure if it's an issue with N/A engines, but it couldn't hurt to have a oil catch can...:)

Bobby...
I wish gimmick made a catch can,I have there turbo inlet/maf hose & would like to keep it all the same under my hood.


joe r
Thanks for all the responses. It seems that this is something much more for the pressurized set and not really more than a bling item for those of us with a NA car. But they do look good! :bling:
Actually these would work better on my Alfa spider than on my Subie.....
he oily suraces will collect any dirt that gets past the air filter... not a good thing!:(
Hmm collect on the oil surface or go straight into the engine, I think I'll take stuck in the oil!

Simon
Excellent post by Arthrogian... the explanation of what builds the positive pressure in the crankcase is on-point.
I had mine sitting in the garage for months now, maybe I'll finally slap it on tomorrow diring the install day.
Would someone please explain oil catch cans to me? I see the term being used and have seen them being advertised but don't quite understand the necessity or usage of them. Is this something used on the turbo cars and actually functional or more just a case of selling an idea that also has some bling and doesn't really do anything on non-race cars? :confused:
If you have a newer style GDI (gasoline direct injection) engine you need an oil catch can. Older style intake manifold injector engines don't need an oil catch can. Since the injector spray would clean the cylinder valves and intake manifold because the gas spray is a good solvent or cleaner if you will. In a GDI engine the gas spray is injected directly into the cylinder so there's no spray to clean the valves or intake manifold. Which leads to carbon and oil build up on them. Putting an oil catch can in the line from the PCV Valve to the intake manifold will limit the amount of build-up. The oil catch can is supposed to catch or remove most of the dirty gas and oil from the crank case pressure air the PCV Valve is sending back to the intake manifold. That's what I've been told Allegedly of course.
Two things:

A. This thread is 15 years old.

Older style intake manifold injector engines don't need an oil catch can.
B. The above statement is false.
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Two things:

A. This thread is 15 years old.



B. The above statement is false.
You're correct. You can add an oil catch can to any engine. Let me rephrase. Allegedly an oil catch can might be more beneficial on a GDI engine.
One thing to consider.
An oil catch can interferes with the designed operation of the emissions control system.
If you have any warranty issue with the engine your claim could be turned down if the service department sees a catch can spliced into the PCV tubing.
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As far as actual emissions, it's as far back as the 1960's. The original crankcase vent was a tube that was angled towards the road surface. There was a black streak on highways from the vent tubes dumping oil and combination byproducts on the road.

If you change your own oil, the content of the catch can can be dumped into the waste oil and taken to be recycled.

If you don't, then you have the dilemma of what to with the waste.
If you don't, then you have the dilemma of what to with the waste.
You put it in with the waste oil at the recycle center.
One thing to consider.
An oil catch can interferes with the designed operation of the emissions control system.
If you have any warranty issue with the engine your claim could be turned down if the service department sees a catch can spliced into the PCV tubing.
My '23 Forester will be my first GDI engine. I bought a Forester because it didn't have a Turbo like the CRV. (ARE YOU LISTENING SUBARU?) I hope the catch can helps extend the maintenance time between intake manifold and valve cleaning versus not having one. But I don't know how it will work because I have no experience using one yet. I don't think it will interfere with the emissions as long as I don't let it get overfilled and block airflow between the PCV and the manifold. It's just another item to maintain or clean out during my 6k mile oil and filter change. I hope that's how it will work. But you know "the best laid plans of mice and men sometimes go astray". I would have to remove it for any dealer service (so I don't make them mad at me) but who knows maybe Subaru has a catch can installed already.
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