Best catch can?
Thread Starter
Le Mans Master
Joined: Jul 2000
Posts: 7,638
Likes: 326
From: Greenville SC
I wish everyone would state WHY they think a certain make is better than the other, and not just "this is the best one" so we can discuss and compare. Most people are going to say the one they purchased is best.
Safety Car
Joined: Jul 2005
Posts: 3,572
Likes: 9
From: Jackson Tn
St. Jude Donor '06-'07-'08-'09
ARE Aluminum catch can is by far is the best catch can I've used.
http://www.drysump.com/catchcan.htm
http://www.drysump.com/catchcan.htm
Former Vendor
Joined: Jul 1999
Posts: 2,103
Likes: 0
From: Indianapolis Indiana
St. Jude Donor '11
Of course mine is the best 
It is sold by CCA and a few other dealers. With a few thousand sold they speak for themselves.
Most of the better catch cans do well and I am personally a big fan of billet over the sheet aluminum models. I tried to keep my cans compact with a reasonable capacity as well being very affordable. I also take a lot of pride that my units are made completely here is the USA and not sure everyone else can say that. If they can that is great.
There is also a mention of a dual can setup. Folks may be interested in these couple pics of a bracket for that.
Thanks.
Mike Norris
It is sold by CCA and a few other dealers. With a few thousand sold they speak for themselves.Most of the better catch cans do well and I am personally a big fan of billet over the sheet aluminum models. I tried to keep my cans compact with a reasonable capacity as well being very affordable. I also take a lot of pride that my units are made completely here is the USA and not sure everyone else can say that. If they can that is great.
There is also a mention of a dual can setup. Folks may be interested in these couple pics of a bracket for that.
Thanks.
Mike Norris
Melting Slicks
Joined: Apr 2006
Posts: 2,151
Likes: 20
All the catch cans are pretty similar. I do like the saiku michi ones myself, but recently I built my own in order to route it correctly. No one offers a can like I want so I built my own. What I did was vent both the valley cover and the pass. valve cover to a single can. Then I vented the can to the non-vacuum side of the throttle body and plugged the fitting on the intake. The reason being to not help the motor suck in any oil. The way I did it the crankcase vents as needed. The other option was to plug both the fitting I did and the t-body and weld on a tube at the top with a filter attached and vent to the atmosphere. It is never a good idea to vent to the atmosphere and still attach a hose to the t-body nipple or the manifold nipple (worse) because unmetered air will be drawn into the motor causing a lean condition (usually a minor one). My can has a baffle I welded inside and I welded on all an male fittings for plumbing and drain. I only had some scrap super thin aluminum laying around so it was a challenge to weld and doesn't look all that great, but it does the job well.
Race Director
Joined: Dec 2000
Posts: 19,304
Likes: 85
From: San Diego CA
Thanks; once you get used to 100% visibility (using glass), you become a bit spoiled. Aluminum may be a better choice in hot areas and in certain climates but I would recommend that a catch can not be bolted directly to a hot engine component. The cooler the "can", the greater the oil entrapment. Of course, the heart of a catch can is the filter and based upon what I've seen, if you use a catch can that contains wire-type media, you might want to install a screen to prevent loose fibers from being pulled away from the "bundle".
Former Vendor
Joined: Jul 1999
Posts: 2,103
Likes: 0
From: Indianapolis Indiana
St. Jude Donor '11
Mike Norris
Race Director
Joined: Dec 2000
Posts: 19,304
Likes: 85
From: San Diego CA
Unless one has a particle counter, and sophisticated vacuum/flow/heating equipment configured to SAE specifications (only one company in the US has this capability), there is no reliable way to measure the differences while simulating real-world conditions.
Talk to any person well-versed in pneumatic filters (designed to trap compressor oil blowby) and he or she will verify that the filter should not be close to the heat source.
A catch can that is cooler than the blowby gas contacting it will allow moisture in
the gas to condense on the inner surfaces of the catch can. While moisture in of
itself is not very harmful, it can react with other residual elements to form acid.
Therefore, trapping both oil and water is beneficial to engine longevity.
Talk to any person well-versed in pneumatic filters (designed to trap compressor oil blowby) and he or she will verify that the filter should not be close to the heat source.
A catch can that is cooler than the blowby gas contacting it will allow moisture in
the gas to condense on the inner surfaces of the catch can. While moisture in of
itself is not very harmful, it can react with other residual elements to form acid.
Therefore, trapping both oil and water is beneficial to engine longevity.
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Le Mans Master
Joined: Dec 2003
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From: San Diego
Melting Slicks
Joined: Dec 2004
Posts: 3,382
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Trackboss...which side do you consider the non-suction side of the throttle body? Got a picture?
Also, do you guys have an explanation why my 2004 C5Z racecar can use no catchcan and use no oil on track at all in a weekend with no visible oil in the intake and my 4 friends running the same car are blowing all kinds of oil and having to drain catchcans daily? But they run older 2001-2003 Z's.
Also, do you guys have an explanation why my 2004 C5Z racecar can use no catchcan and use no oil on track at all in a weekend with no visible oil in the intake and my 4 friends running the same car are blowing all kinds of oil and having to drain catchcans daily? But they run older 2001-2003 Z's.
Melting Slicks
Joined: Apr 2006
Posts: 2,151
Likes: 20
The barb on the t-body is non-vacuum. The barb on the manifold is vacuum.
My '99 uses no oil and next to nothing in the catch can even after a day at the track. This was even before the current can. What is weird is I'm told that occasionally there is some smoke out the exhaust under deceleration. Also, I find the intake manifold gets pretty oily. Not sure how it gets there and somehow bypasses the can(s). The current catch can up above I have yet to test on track, but will in the next few weeks. I do know that on the dyno, the old setup ran just a tad leaner than the current one.
My '99 uses no oil and next to nothing in the catch can even after a day at the track. This was even before the current can. What is weird is I'm told that occasionally there is some smoke out the exhaust under deceleration. Also, I find the intake manifold gets pretty oily. Not sure how it gets there and somehow bypasses the can(s). The current catch can up above I have yet to test on track, but will in the next few weeks. I do know that on the dyno, the old setup ran just a tad leaner than the current one.
Melting Slicks
Joined: Dec 2004
Posts: 3,382
Likes: 250
My thinking is you want blowby out but a crackcase vacuum if you can. You don't want the pumping of air in and out of the crankcase. So I like your idea of valve cover and valley into one can. I was thinking that too as a possibility. But what about venting the line to the T body to the atmosphere instead via a breather to guarantee no oil in the intake BUT put a check valve in the line before the breather so that air can come out but nothing goes back in? I'm racing of course no interest in being smog legal.
Race Director
Joined: Dec 2000
Posts: 19,304
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From: San Diego CA
As I mentioned, previously, the maintenancefree-for-a-year goal of most catch can designs require that the filter not get clogged too easily. This is why I advocate a mounting location that aids in the oil removal process.
Race Director
Joined: Dec 2000
Posts: 19,304
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From: San Diego CA
I'm glad it's working out for you, Jorge.
Melting Slicks
Joined: Apr 2006
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fatbillybob, in your case I would recommend you install a catch can the way I have on every race car I've ever built or worked on. Vent all lines to one can with a filter on top so it goes to the atmosphere. Plug all barb fittings on the motor. This is by far the best way to vent a motor. On street cars it is not all that practical. Especially since smog is a concern. In addition, on the race cars I've always welded -12 fitting on the valve covers (wet sump motors only). On the corvette, that is good as well, but the valley is a good place to allow breathing as well. You could build a catch can with three inlets to vent from all locations.
Dave68, I built my own catch can above. I welded a baffle in it, but there is no filter. In any case, even with some oil in the intake (not yet with this can), the car runs well. I placed the drain on my current can so it is very easily drained if it ever needs.
Dave68, I built my own catch can above. I welded a baffle in it, but there is no filter. In any case, even with some oil in the intake (not yet with this can), the car runs well. I placed the drain on my current can so it is very easily drained if it ever needs.
Melting Slicks
Joined: Dec 2004
Posts: 3,382
Likes: 250
So what do you guys think of check valves in the bleeder lines? crankcase air ok to the atmosphere or T-body but no air flow back to the crankcase. I think check valves make sense. Maybe ones that are used for fuel tank vent valves should be cheap and available.