mine has been on for about 300 miles and seems to have collected about 4 oz of water; no oil I could see.

I'm curious about others' results and where this condensation is coming from. I Tee'd the tubes from the valve cover vent and the PCV valve into the c can. the c can out goes to the intake on the ambient pressure side of the TB. (the tube going to the intake to the blower is now plugged)

I'm using the $40 version of the M7 type can.

 

I'm not a wiz on this mod for a MINI, but on other cars this is wrong. UNless the can is vented, you really should just put the can inline between the valve cover vent and intake. Most catch cans strip the oil of off the air through steel mesh.

But like I said, a MINI may be different then a Honda or Neon.

 

Here is a good "How to" from the EVO boards:

http://home.earthlink.net/~ejhonda/evoPerrin.html

 

I think your's might be hooked up wrong

I need to look at mine again and remember how I did it. I do know that within a month there is some oil in the the can, though not a whole lot. I see it as working very well so far.

 

mine is hooked up like this:

https://www.northamericanmotoring.co...achmentid=1023

I made a couple of mods:
the line with the Tee in it is the flow into the can; I extended the tube through the barb fitting right down to the bottom of the can.
the entire can is filled with a stainless steel scubbing pad as a condenser;
the output from the can comes from the top only and is connected to the intake.

so it seems hooked up right and is vented

 

My Alta catch can collected only water also. I emptied a little over a half cup every fill-up. I removed the intercooler at regular intervals and still found new oil in the end tank boots. When I removed the can and hoses there was oil in the tee between the two vents, but none in the can. There was also the smell of crank case gasses coming into the cabin when the fresh air vent was open (can in cowl location). The installation was correct and there were no leaks at any clamps.

 

Same here...oily water only I have the Alta...is this a hoax?

 

The idea behind the catch can is to intercept the oil vapor that is in the line between the valve cover breather and the induction hose. This would be the nipple on the right hand side in the photo. However, I'm unsure where one should be tapping in the one on the left.

 

jlm's diagram is correct. If you have the CC hooked up like this it should be working as it is in my MCS.

Below are two photos. One showing the oil I have collected in about six weeks. No water in there.

The other shows how I have run my lines in front of the motor. I try and keep everything as clean and clear from the under and back side of the intercooler. Better air flow.

 

both of those tubes are open to the valve cover interior; the only difference is that the left one has a PCV valve in line.
the straight vent is usually connected directly to the ambient side of the throttle body, an area which never sees vacuum, but can cause suction in the line due to flow across the tube.
the PCV line is usually connected to the area between the throttle body and the blower, an area that can see vacuum under closed throttle conditions. Presumably, this is the suction that would be getting the highest volume of cranky breath.
with the illustrated hookup, both cover vents are hooked up to the ambient side of the throttle body and the catch can is a trap to separate liquid from the stream.

 

Disclaimer: You may ignore this post if you dare, but you will be risking performance and engine damage.

I am not a BMW/MINI technician, but you should not reroute the PCV from a vacuum source to atmospheric only. I don't know how this got started in the "tuning world" but it is a no-no.

The crankcase vacuum created by the tube running from the PCV to the suction side of the engine (behind throttleblade) is REQUIRED for the piston rings to seal properly. This greatly (immensely) reduces blow-by and provides a tight combustion seal. Some studies have shown this to be the primary sealing method of the rings since most modern day engines use low-tension rings to reduce parasitic drag.

Also, since the MINI is a positive pressure engine, blow-by (air bypassing the piston ring seal) could pressurize the crankcase if the rate of air out of the atmospheric vent (that 10mm silicone hose) is less than the air going in. This will cause leaky seals, poor idle and light throttle driveability. It will also pump oil the other way, pushing oil past the rings and into the cylinder, causing combustion contamination.

Racers pay big bucks for specialized crankcase vacuum pumps to increase performance and reliability beyond the typical PCV system.

A oil catch can on the crankcase vacuum leg is used to strip the oil out of the air stream. The oil catch can on the valve breather side is to catch oil that may slosh into the tube from high g-forces, or overfilling, and not recirculate it into your incoming clean air supply.

In the previously supplied link,

http://home.earthlink.net/~ejhonda/evoPerrin.html

the installation of the Perrin (which is Alta) on the EVO/WRX only intercepts the valve cover breather hose (by the oil fill cap on the MINI). This is the same on the Dodge SRT-4, Ford Focus RS, VW 1.8T and Ford Mustang SVO.

But then again I am not a BMW/MINI technician, so maybe its completely different then everyother OEM.

 

Good post minimotor. I will ask around about this, thanks
What is ".....and light throttle driveability"?

 

[font=Arial, Helvetica]PCV Valve Operation Modes[/font]

[font=Arial, Helvetica][/font] [font=Arial, Helvetica]High Manifold Vacuum, Low Crankcase Pressure[/font]

[font=Arial, Helvetica] This mode corresponds to the idle condition. The pressure differential presses the disk against the intake manifold side seat, where the metering slots permit a regulated flow of gasses into the intake manifold. This flow is kept to a small amount so as not to decrease manifold vacuum level and cause the ECU to richen the mixture.

[/font] [font=Arial, Helvetica]High Manifold Vacuum, Moderate Crankcase Pressure[/font]

[font=Arial, Helvetica] This mode corresponds to over-run (coasting in gear with the throttle closed). In over-run, manifold vacuum can exceed 20 in. Hg. Under these conditions, the disk is pressed against the intake manifold side seat. A small amount of flow is passed through the metering slots. Blow-by is minimal as combustion is at a low level.

[/font] [font=Arial, Helvetica]Low Manifold Vacuum, Moderate Crankcase Pressure[/font]

[font=Arial, Helvetica] This mode corresponds to part-load conditions. When the pressure differential becomes greater than the spring tension against the disk then the disk floats between the intake manifold side seat and the crankcase side seat and a large flow of gasses can be passed through the valve. This is the normal operating position of the valve when cruising under light to moderate part-load conditions.

[/font] [font=Arial, Helvetica]Very Low Manifold Vacuum, High Crankcase Pressure[/font]

[font=Arial, Helvetica] This mode corresponds to heavy load to full-load conditions. Here, most of the pressure differential that opens the PCV valve comes from crankcase pressure. Under heavy load, blow-by gasses are at a maximum and the PCV valve is open to permit the gasses to be passed to the intake manifold for re-burning. If the blow-by volume exceeds the ability of the PCV valve to draw in the vapors, the excess blow-by flows back through the crankcase fresh air intake system to the air cleaner box, where it is pulled through the throttle body and into the cylinders.

[/font] [font=Arial, Helvetica]High Manifold Pressure[/font]

[font=Arial, Helvetica] This mode corresponds to an intake backfire condition. Here, the high positive pressure in the manifold presses the disk tightly against the crankcase side seat, sealing the PCV valve and preventing flame propagation into the crankcase to prevent an explosion. The crankcase fresh air intake system incorporates a flame trap that prevents the flame front from propagating into the heads.

[/font]

 

MiniMotor: very interesting;

I thought I was following the Alta recommended hookup, but if what you are reporting is the right stuff, we need two catch cans, one in the PCV/vacuum circuit, one in the vent circuit. I'm changing my hookup to put the c-can only in the PVC circuit with the can-out going back to the blower in tube.

 

An engine is an air pump, as the pistons go up and down in there bores, they "suck and blow" air. As the piston tries to transverse down the cylinder bore, air is displaced under it. if this air isn't vented, pressure increases, and resistance is created. Try taking two same sized paper cups in your hands and quickly stacking one inside of the other. There is a rush of air out from around the diameter of the inner one and a resistance is felt. Now, poke a finger-sized hole in the bottom of the lower one and repeat. They quickly go together and the air is rushed out the bottom hole. if you really want to get creative, put the inlet of the vacuum cleaner hose covering the hole on the bottom of the lower cup, and gently place the top cup into the lower. The top cup is sucked down into the lower quickly.

You've just simulated how a piston, piston rings, and the PCV system operate.

Now, how does this effect light throttle performance?

As an engine begins the induction stroke of the four-cycle combustion cycle there are a few forces acting on the piston. The greatest is inertia, the rotating mass of the assembly continueing to rotate the crank and pull the piston down in the bore. The second is the pressure differential of the incoming rush of air/expanding area above the piston and the pressure below the piston. We'll concentrate on this pressure differential.

Ideally you'll want this pressure differential to be as great as possible to aid the descending piston, i.e. maximize your crankcase vacuum. This also helps to seal the piston rings as previously stated up in the postings.

A hestitation is felt/created with poor or non-functioning crankcase vacuum systems because the pistons needs to overcome this resistance of the air compressing below the descending piston. Now the inertia force is much greater than the resistance of the air, but as they say, ever little bit counts, and this time, it's counting against you. At light throttle, high vacuum is created in the intake manifold (above the piston). If the PCV valve is not hooked up, and no crankcase vacuum is present or it's at equilibrium (or worst yet pressurized!), the engines motion is interupted ever so slightly more, creating the "light throttle driveability" or hesitation.

Hope this helps. note, i did not have time to spell check this.

 

..... have got to get this figured out here. The last thing I want to do is drive without an effective Oil C Can. The intercooler is such an important HP ‘re-gainer’ that I don't want to risk getting oil in it.

Anyone want to try and sketch out what should be done? I am personally a bit lost here.

 

there is a tube from the PCV valve (left side of the valve cover) that connects to the runner between the throttle body and blower intake. That is the line pressure Mini-motor is referring to. the idea is to separate the oil from the vapor in this line. inserting the catch can in this line will have no effect on the crankcase pressure/manifold pressure conditions (as long as the ccan can deal with being under vacuum)

 

Has anyone bothered to open up the intercooler after installing a catch can to see if oil is being stopped? That is where the oil is collecting right?

 

One of my other projects ran two catch cans:

1. A vented can for the valve cover breather (right side of MINI valve cover)

2. A closed can that went from the PCV valve (left side of MINI valve cover), into the can, out of the can, and to the tube after the throttle body.

I would run the second one (PCV) as a priority given the choice between the two. Make sure the can has steel wool inside of it and the it sits lower than the valve and the tube. This way any stray oil will dribble back into the can.

 

Hello guys, I'm a Alta catch can owner too and have tried Alta's hook up and found out that just like a couple of you guys, only got a little water in it after some months.
I then un-hooked everything, re-connected the catch can to the PCV side only and back to the Gray line that was capped off.
After that, I got results.
I just checked mine yesterday and have about 1/2 inch of oil from the bottom up. Also noticed that the inside of the can is gouged and torn.
This happened from the vacuum put on the can by that Gray tube. I'll try and get pics. on here to show you guys tomorrow, but now I think I need a alum. can to be able to handle the vac.

 

Not sure, but after looking at the install pics and diagrams from this post, I don't think things are hooked up right. Here is another serious of posts from here at NAM, and this is how I have traditionally seen it done. Just thought i would share.

https://www.northamericanmotoring.co...=catch+install

Here are some shots from the vendor's sites as well.

 

One thing you forgot to mention is that in an engine with an even number of cylinders you will have the same number of pistons going up as you will have coming down....so there will be very little, if any, pressure created.

If this is such a problem, why are there no "vacuums" on a normaly aspirated engine? Just a breather tube from the pvc valve to the intake.

Here is how mine is hooked up.........

 

Good point. True, at slow, progressive speeds there would be equilibrium and I have simplified the explanation. In actuality, when a piston in moving at speeds approaching 65 feet per second there is a different phenomenon going on inside the crankcase based upon pressure waves moving within conjoined vessels. Suffice it to say, there would be an instantaneous air resistance created as the piston tries to accelerate the "static" air under it.

Again, this would be minimal to the inertia forces. And most of the hesitation would come from the poor sealing rings that aren't helping to draw in the air/fuel charge on initial valve opening and the combustion contanimation.

RPM Av Piston Speed (fpm) Max Piston Acceleration (ft/sec2) 1000 563.33 2030.02
1500 845 4567.56
2000 1126.67 8120.1
2500 1408.33 12687.66
3000 1690 18270.22
3500 1971.67 24867.8
4000 2253.33 32480.4
4500 2535 41108
5000 2816.67 50750.62
5500 3098.33 61408.25
6000 3380 73080.89
6500 3661.67 85768.55
7000 3943.33 99471.22

 

I dont recommend steel wool in a non vented catchcan because its somewhat easily sucked into your intake stream. You're better off using some other larger type of media of with a high surface area. I'd recommend checking out the media used in wet/dry filters. Someone else recommended to me using a long length of ball chain.


--
Cheese

 

How about one of them metal pot scrubbers that look like a ball of metal shaving?