Oil Catch Cans?

[buzzdog]

Hey Guys,

Was just wondering if Oil Catch Cans are necessary? I've seen a few different methods of how turbo owners manage their rocker cover breather hoses and was wondering what is the best way, if any at all, to manage this part of the vehicle. The methods I've seen so far are:

1). Just your standard hose from your rocker cover breather to your intake pipe, (is this as destructive as they say it is?)

2). A small performance air filter clamped straight onto the breather nosel, and

3.). Installing a catch can. (If so, how do you install one?)

The more I read and the more I look into management of the breather, it becomes apparent that if you can you should at least put a Oil Catch Can if not, go straight for the filter and filter only.

Any info and or personal experience is appreciated.

Cheers

Buzz

[RAP1D]

Legally you must have the breather running back into the intake, between air filter and TB.

As per factory, this is the way it is already and fine on low standard boost, once boost is increased their is a greater chance of oil vapours entering the intake system, and into the combustion chambers, and oil isnt good for combustion so the more oil in there the greater chance of detonation.

With the XR6Ts getting older now, motors are more prone to blow by and turbos can loosen up and blow more oil, so a catch can system is well worth using.

The old filter on the rocker cover works well, but isnt legal so keep that method for race cars.

[buzzdog]

Cheers for your response RAP1D,

Have ever installed or been involved in the installation of an oil catch can? If so, are the difficult to install and are there any notes/tricks/tips that one should know in regards to oil catch cans and their installation?

Cheers

Buzz

[turbotrana]

There is a right way and wrong way to do catch can setups. This is the right way.

Consider the breather setup in two parts.

The first is the PCV part. This sucks in air from the rocker cover into the inlet manifold and operates during idle and cruise. I build a little catchcan and install it in this line so that it keeps the inlet manifold clean. The catchcan is a design that catches 99% of oil and drains it back to the sump on shutdown. It is based on a design I copied from boat breather setups.

Then you have the breather overflow when the engine is on load. (the pcv is not used under load). This goes usually from the back of the rocker and then infront of the throttlebody and in case of turbo in front of the turbo inlet. I usually enlarge this hole to 1" and build another catchcan to catch the oil that comes out of the rocker cover under load. This prevents excess oil being injested into the engine. This can be vented to atmosphere but as I want an emission compliant engine and because my catchcan is very effective, the fumes are very clean and once again the caught oil gets drained back into the tank.

Because of this setup my emissions are way cleaner as minimal oil gets back into the engine.

Essentially its two catchcans to do the job properly. By disconecting the original PCV valve, putting a little filter in its place is all wrong and shows a complete non understanding of how it all works.

[RAP1D]

Its a good idea not to touch the PCV system at all on modern cars, just run the oil/air separation system off the engin breather fitting...tampering with the factory PCV fittings will make it look like the emmisions systems have been changed, and you'l most likely end up with a sticker on your window.

Buzzdog, there's a few threads on here from guys that have done simple catch can systems.

[turbotrana]

In my case the "catchcan" word is the wrong word to use. Cheap catchcans have minimal effectiveness. The correct word is oil/air seperator. High end boats use a brand called Racor but these are too expensive for auto use.

I misplaced my camera so cant show pictures ATM. There are many ways to skin a cat. I use exhaust tube to make them up. Basically 3" outer tube, then 2.5" perforated muffler tube located centrally in the 3" tube and then 1.5" perforated tube located centrally within the 2.5". Inbetween the 1.5 and 2.5 tube you push in stainless steel scourer pads to completely fill in that void. The can is usually made 6" long. Plates are welded to each end. The inlet comes in from the 3" outer tube, swirls around and then goes through the perforated tube and SS mesh into the inner tube and exits via a fitting at the top.

The collected oil needs a fitting at the bottom to be drained manually or one way valves can be used to drain into the sump on shutdown, but then you need to make a fitting in the sump or even the block. It is very effective in catching the oil from the vapour.

I do it more to pass emissions than performance but it keeps the air tracks of the engine much cleaner.

[dashturbo]

I dare say that the amount of oil that goes into your intake would make no difference to power. if anything it will lubricate more stuff and help your engine with wear.

That said, I have seen old turbo cars (nissan motors mainly) that are blowing a turd load of blue smoke and the "catcher can" seemed to help, although it needed draining every fortnight!

If the PCV is working properly it will only affect power on light throttle application, not idle and not full power. So who cares?

[buzzdog]

Hey guys,

Thanks for all your responses in regards to Oil catch cans and their installation.

I think in my case it's more of a preventative measure as my turbo is getting on as well as bit of under hood visual appeal. That said, I'd like to find a system which is effective at serving the purpose of seperating the oil.

Just to clarify some terminology, the breather overflow is the hose further most to the rear of the engine and the PCV is the hose centre most on the rocker cover, is this correct?

Also, what is a good price for oil catch cans and are the ones on E-bay any good?

Cheers

Buzz

[PHANTMXR6]

  On 27/01/2010 at 11:08 AM, buzzdog said:

Just to clarify some terminology, the breather overflow is the hose further most to the rear of the engine and the PCV is the hose centre most on the rocker cover, is this correct?

Other way around champ.

The hose on the rear of the rocker cover has the PCV in the end of it.

The breather tube goes from about the middle of the rocker cover back to the supply side of the intake plumbing to the turbo.

[PHANTMXR6]

  On 27/01/2010 at 5:24 AM, dashturbo said:

I dare say that the amount of oil that goes into your intake would make no difference to power. if anything it will lubricate more stuff and help your engine with wear.

Are you serious??

An engine will most definitely not benifit from oil ingestion. It's quite the opposite. Oil will lead to carbon buildup on components like valves and the top of pistons. When that carbon breaks off it damages things like valve faces and seats, not to mention turbine wheels of turbochargers. Also, it can effect things like throttle bodies and sensors.