: How much oil can a catch can catch?

06-02-13, 04:22 PM
The first I heard about a catch can was from this forum. After some research I figured out what it does and how to install one. I'm a conservative driver (don't think I've ever reached 5K rpm and average over 18 mpg) so I was surprised to find my Monson CC full in less than 1K miles. After monitoring collection I find I discard about 4 oz. each 1K miles. The significance being not only that I'm protecting my entire intake from significant contamination, but at this rate of a quart/8K miles, the amount I need to add to the crankcase, my engine virtually burns no oil, so consider this when factoring in oil consumption. The Monson product is obviously very efficient. The only drawback is that the small container holds only 3 ounces so it needs frequent attention.

06-02-13, 06:30 PM
Wow, I'm not sure I could enjoy this car keeping it under 5k rpm. You need to get out there and do some no lift shifting! :)

06-02-13, 11:00 PM
I think these are a solution to a problem that "may" not exist. I haven't seen a story where there were significant issues like misfire, lost horsepower, leaks, etc, associated with NOT having a catch can. In a race motor, it maybe a different story with crankcase pressures. Does a falling tree make noise when it falls in an empty forest?????????

06-02-13, 11:00 PM
LOL, I was proud of myself for passing 5K RPM only 3 times today...

Back On Topic: any pics of your catch can install, or links to another thread? These seem to be very critical in the direct injected V10 in previous gen Audi's, didn't think they were on my radar with the LSA...

06-03-13, 02:11 PM
All cans have different capacities before all the oil just passes through. Most are only 8 ounce total internal size, but since any more than 3-4 oz's reaches the point any more is 100% pulled through you want to empty every 1000 miles max. A 1 qt is the minimum internal volume that will allow the speed of flow (velocity) to slow enough that the oil droplets can fall out of suspension.

Also realize, no matter how well known the brand name, no matter how nice one looks, only a few actually stop all or nearly all the oil. Most at best catch 40-50% and the rest is still pulled into the engine so the problem has not been prevented.

Only the RX, Saiku Micchi, and the Elite Engineering come close to catching all the oil, and only the RX catches all the oil.


06-04-13, 11:25 PM
I apologize. The product was a MOROSO catch can, not Monson. Hope I didn't inconvenience anyone or hurt my credibility. Have to put brain in gear before typing.

To view the installation visit the Moroso website and click on instructions then model 85602. The only difficulty I had was removing the stock valley to intake U tube. To see how the clip opens practice on a similar, but well exposed, clip for the clean air supply on the valve cover and then tackle the hard to reach U tube with extended reach tools. Other than this the installation is a piece of cake. The can fits nicely in an open spot near the intercooler fill. This is right above some electronic module or computer, which I cover with a towel when emptying the container.

I read past threads where RX and other brands were more highly recommended and am not sure what sold me on the Moroso. Perhaps it was the easy installation and available demos. Since I would have been satisfied with merely catching some of the oil I was very surprised to find a full can at 600 miles. I must be catching all of the oil since it's the total my engine uses. Aggressive driving could permit oil to escape, but for me it's perfect.

I'm not saying this is for everyone. I love the car and strive to protect what Car & Driver called "the best car America will ever make." Crankcase ventilation, a necessary evil, can't be good for an engine. I realize that engines can perform for hundreds of thousands of miles, sucking oil, but can't see dumping a quart of dirty oil down the intake every 8K miles, coating the SC internals, intake valves, plugs, cats and O2 sensors when there is a simple, inexpensive solution. What was interesting is that a healthy engine can be expected to lose at least a quart of oil per oil change through the PCV system.

06-05-13, 09:28 AM
This is off subject slightly, but somewhat related. Has anyone using the oil catch can (any variety) experienced cold weather water vapor freezing inside the can. Obviously I are talking extreme cold conditions. Some of our trucks up north have this problem and result in engine seal leakage from blocked ventilation due to ice build up. Just curious.

06-05-13, 10:09 AM
IMHO a catch can is a waste of time and money for this engine. It's not DFI, the valves will be kept clean if you use good quality fuel. If you are driving mainly on the street.. what's the point? Frequent oil changes and a bottle of Techron once in awhile is all you need.

06-05-13, 04:49 PM
Only the RX, Saiku Micchi, and the Elite Engineering come close to catching all the oil, and only the RX catches all the oil.


I'm sure I'd be happy with my Rx catch can - if I could ever get it. You have been sitting on my $200 since May 4th when I paid for it online as an in stock item; it's 31 days later and still no shipping notification. My past two emails have been dismissed with "it should ship in 7-10 days."

Of course, that was 3 weeks ago.

You may build nice cans, but "RevXtreme" completely sucks at customer service and delivering a product in a timely manner. My CTSV - as in the entire ****ing car - was literally ordered, built and delivered across two states in less time than it apparently takes you to make a two-chamber aluminum can.