Provent oil catch can

[Profister]

I think this topic did not have enough coverage, so I dare to post this. The friend of mine installed a German made Provent oil catch can on his Pajero to keep an intake manifold, an intercooler and a turbo clean. I got one to install it on my L400 when it arrives. Here are some pictures to give you an idea what I am talking about.

[strada-caster]

I just finished putting one on mine. It would seem my truck was eating about 100ml of oil every 1000 kms. I'll find out more exact numbers in a while.

Mine was homemade.
-stainless steel water bottle
-barbed fittings
-JB weld
-water bottle bracket(for a bike)
-extra hosing.
30 bucks..yeehaw.

[Strada 92]

Strada-Caster,really interested by your catch can.
Do you have some picture?
Thanks.

[madmazda]

I've made one out of copper fittings and a k&n filter on top... now to just find room to mount it

[lopar]

I got one to install it on my L400 when it arrives.

Where did you get? Cost?

[Profister]

FYI
http://picasaweb.google.ca/lh/photo/8GO ... directlink

[psilosin]

Profister,

That Mann catch can is the best looking design I have seen (ie compared to the useless Greddy etc units with no baffles etc...but are CHROME lol). Where did you order it from? Do you know what the inlet/outlet inner diameters are?

*edited: wow my grammar & spelling in that post was like I was really drunk. Must need more coffee...sheesh.

[fexlboi]

Where did you order it from?

http://www.republicsales.com

You also can get it here: http://www.airnowsupply.com/tdi.htm

[Jaz]

Just cross posting this from another forum when a similar topic came up as to the effectiveness and whether it is worth having a catch can. What this guy actually suggested is that while catch cans in general are okay, it's still a closed system and you're not entirely getting rid of the vapours. He suggested that if you actively "scavenge" the vapourous (word?!) air from the system and get rid of it by using a high pressure/low pressure system then you never have to worry about emptying catch cans or oil vapour in your engines system again. This is through connecting the factory breather system (which is what you would plumb your catch can into) to the exhaust, and using the low pressure caused by the exhaust (with the connector on the right angle) to drag out any vapour, and also to help air travelling through the system. Anyhoo, that's my take and "cliff notes" on the post, but here it is in full. It's at least food for thought :)

(Oh, this came up when someone posted about a Grimmspeed catch can, hence the mentions of that and variations of the word... "grimmstain". Also it's in regards to EJ20 4cyl Subaru motors, hence the mention of EJ, but similar principles apply with the Deli motor.)

Short version, venturi effect. Create a low pressure zone behind a flowing gas (in this case, exhaust) and it will suck from that area. Much like a passive water pickup on an inboard boat engine etc.

By no flow, I meant there is zero net pressure difference between crank case and the head breather pipe (as its all the same airspace). So there is no active push from the headers, up a pipe, to separator and magically down a fill pipe into the same cavity. You need to create a differential pressure for it to work. On a 4cyl engine like an ej that is so close to an opposed firing order, I think you'll find crank case pressure to be quite low so even a catch can is only an effective means when you have adequate blowby (and we all like a good blow by to get fluids up a tube).

Remember a catch can's downstream side is at atmospheric pressure and its upstream is at crankcase pressure (which is positive due to blowby and somewhat as an inherent function of piston stroke (this is most easily envisinged in 1 cylinder applications)). You have nothing to push any oily air or particles of oil out of a breather pipe in a closed loop system. Somewhere you need to create a differential. Plumbing a catch can's downstream outlet to a pre turbo intlet is how the factory does it as it is constantly at vacuum, and hence lower pressure than the crank case. a PCV simply diverts this directly to the manifold in vacuum situations post turbo (overrun, off boost, etc).


Here is a pic i googled of a setup of then venturi pipe set up incorrectly (it's upstream of the o2 sensor, $#&*$).

What you want is something designed by someone with a clue, ideally you would have an intersecting pipe just past your o2 sensor (as high as possible in the dump) at maybe 20 degrees off the angle of the pipe, and its internal surface would be a total of 60 odd degrees adjacent to the flow direction.
, with the entire thing on the above 20 degree angle too (to prevent reversion).

This will not revert (exhaust up pipe) no matter what the rpm. Such a situation would require a: 120 degree turn of flow to revert (nigh impossible), and b: a higher backpressure in the exhaust than in the breather line (impossible, one is a bit of half inch pipe, the other is a 3 inch hollow bit of steel). The benefit is a linear increase in effectiveness with flow speed (rpm essentially) to create a higher vacuum the more crankcase buildup occurs.

The key also is knowing that backpressure is a $#&*$ joke american wank for dirty 2 valve v8's that have no overlap and hence get a bit of torque from the extra little compression during the exhaust stroke. Turbos require no back pressure. Look at an old F1 turbo exhaust, or a side piped 5 inch drag exhaust. Believe me they have none, and work fine.

anyway

So now you're venting oily crank case shit to your exhaust at one of its hottest points. Great, smokey! (maybe...high temp it would probably burn fairly clean)...so prior to venting straight to the exhaust, you vent through a baffled catch can. The magic is in getting the sizing and volumes right to remain effective, yet still promote oil buildup on surfaces (a poor mans coalescent filtering, what grimstain doesnt achieve yet claims). This might take some dicking about, but I reckon its fairly easily doable...personally I'd rather just let it burn, who gives a ^&%$#@ about cat converters anyway

A closed loop system just doesnt work. Also, food for thought, go run your engine, and take the filler cap off and feel the air movement out. Then remove a breather and feel it, I guarantee more is coming out of the filler neck due to it being the lesser back pressure. A closed loop system would have to work in reverse to how grimspeed claims due to this. (this would be useless too).

If you want air/oil separation on the track, either actively scavenge with a pump, or passively scavenge using the existing forces you've already spent energy on to create (gas velocity). A pump is a parasitic loss in it self, but the gains are definitely worthwhile, hence they're used. The last option is to just vent to a catch can that has a breather on top, or a breather leading to the intake pre turbo. Your existing setup works, the only thing better is option 2 or option 1.

A breather leading to the turbo intake is a shit idea as oily intake air = robs power yet still consume the oil = futile. At least it seems clean though.

[mararmeisto]

...[w]hat this guy actually suggested is that while catch cans in general are okay, it's still a closed system and you're not entirely getting rid of the vapours...

Which is the whole point - it's an emissions-control implementation. The poster has provided what looks like home-garage-science to detail a more complicated oil trap, but the simpler science is that by putting flow through an obstructed pipe (like a catch can with an input at the top, a filter, and an output opposite the input) the majority of particles of oil suspended in the 'air' will fall out and not be carried through to the intake to the turbo.

It's not about getting rid of the vapours, an oil catch can is about getting rid of the oil from the intake air for the same reason you want the dirt removed from the intake air. Same reason there is a paper filter in the air intake pipe.

[Jaz]

Definitely - my post above wasn't exactly a closed emissions loop.

A regular catch can will get rid of most oil vapours in the system, however he was detailing an add-on system to that which actually helps to draw the air through and lower the pressure within the system, creating less resistance. It was more food for thought than a "this is the way you should do it", as I believe if you get stopped by the police and they see that it's vented to atmosphere, then you will get bent over.

[mararmeisto]

I've installed my system now. Don't know that it's going to make any great improvements in performance, but it will clean up the intake air and intercooler system (which was/is quite oily from all previous emissions). Oil catch can is from 42 Draft Designs in Maryland - looks like a VW performance shop.

Check out my blog for further details and a couple of pictures.

[Mr. Flibble]

Profister,

That Mann catch can is the best looking design I have seen (ie compared to the useless Greddy etc units with no baffles etc...but are CHROME lol). Where did you order it from? Do you know what the inlet/outlet inner diameters are?

*edited: wow my grammar & spelling in that post was like I was really drunk. Must need more coffee...sheesh.

But Chrome *INCREASES* the performance of *EVERYTHING*!

But seriously, I actually ordered a Chrome Ebay unit. Why? Well, I was originally considering building one out of an air hose filter from Home Depot for cheap, then I figured I would just order one that does the job and is already made. I think that going for all the extra stuff like baffles and filters is a bit of overkill given that the Delica does not even come with a can in the first place!

And, given that it was $3.00 extra to get a chrome vs. non-chrome, I went all out on the $$bling$$.

[dfnder]

[quote="Mr. Flibble"]

But Chrome *INCREASES* the performance of *EVERYTHING*!

Now I KNOW what the flashing eyes have been trying to tell me!

[Profister]

Finally I put my hands on my new ride and the Provent oil catch can is in along with some other goodies. The first picture illustrates the reason for this modification and the second one shows how a Provent looks installed: