Last weekend I rehabed the AC system in my 05 Merc C230 Kompressor. To get to the compressor I had to take the intake off the car and noticed a good amount of oil in the intake piping ect.
Are there any good tutorials on where/how to install a catch can, from what I found it looks like the car needs one.
Catch cans are one of the easiest low risk things to install. Find the appropriate PVC line.
Yeah, just plumb it in line with the PVC, preferably close to the intake where it gets good vacuum.
For a really trick setup I have seen some folks set it up to drain back into the sump so that it doesn't have to be manually emptied, but that takes a lot more work.
This is something I created YEARS ago when I had a SRT-4. It's SRT-4 specific, but might help. The big thing on this car was a check valve because of the turbo.
Both work, some systems have two. My g8 has two catch cans, although it doesn't really need either.
In reply to Gimp (Forum Supporter) :
Thank you for that visual. I've been kicking around the best way to do a catch can on my SRT4 and a lot of the old forums are now pictureless
camopaint0707 said:Catch cans are one of the easiest low risk things to install. Find the appropriate PVC line.
You say that, but we had a fire on track at last week due to an incorrect catch can install. The can would fill up before the end of the session and start burping oil out of the filter. It was located right over the exhaust manifold. Owner thought he had it fixed, then on one session the filter blew right off. Oiled about 1/4 of the track and the car caught fire after he brought it to a stop. Luckily he had an extinguisher but it was a great illustration about how you can get it very wrong. Also, about how much blowby is too much.
Owner also had a better catch can on the PCV side, the problem one was on the valve cover inlet - think of Gimp's diagrams but with a filter instead of the stock airbox. Now that I think about it, he was probably pressurizing the valve cover because he was probably counting on the PCV valve to work as a check valve. That can work with the right PCV, but not a stock Miata one.
One other thing to point out- if you are going to use a catch can for oil, you should probably include a separator, too.
Alfa's came with oil separators that just drained the PCV oil back into the sump instead of worrying to drain a catch can.
alfadriver said:One other thing to point out- if you are going to use a catch can for oil, you should probably include a separator, too.
Alfa's came with oil separators that just drained the PCV oil back into the sump instead of worrying to drain a catch can.
That would be nice. Mine fills up over the course of a track day. I wonder if I could tap my dipstick location to drain?
The Camaro 1LE had a nice little separator that replaced the oil filler and thus drained back into the head. Clever piece, got rid of oily intakes on cars with the ASA cam, crazy easy to install on LS engines if you have the vertical space for it. I use one on the Targa Miata, can get pics upon request. It'll fit other GM engines as well.
https://zl1registry.com/1le-oil-separator.php
The Clean-Air Separator:
Replaces your oil fill cap and stops oil ingestion for the brief period when at WOT the reversion pulses from valve overlap overcome the intake manifold vacuum allowing reversion flow from the valve cover to the intake air bridge. This accounts for only 2-5% on average as the dirty-side (Catch Can Side) is where almost all oil is ingested, but with today's direct injection engines and the intake valve coking issues, and any forced induction to avoid detonation caused by the oil ingestion, you want all paths of ingestion covered.
Thanks everyone. Now to pick out something and find the time to get it installed.
theruleslawyer said:alfadriver said:One other thing to point out- if you are going to use a catch can for oil, you should probably include a separator, too.
Alfa's came with oil separators that just drained the PCV oil back into the sump instead of worrying to drain a catch can.
That would be nice. Mine fills up over the course of a track day. I wonder if I could tap my dipstick location to drain?
Exactly where the Alfa drains to.
alfadriver said:One other thing to point out- if you are going to use a catch can for oil, you should probably include a separator, too.
Alfa's came with oil separators that just drained the PCV oil back into the sump instead of worrying to drain a catch can.
GTI's are similar.
Keith Tanner said:The Camaro 1LE had a nice little separator that replaced the oil filler and thus drained back into the head.
That's how I built the one on my '61 Apache. Drilled and tapped the oil fill cap for a -10AN fitting, hose uphill to the bottom the the catch can, separator stuff inside, and top of can going to air filter for fresh air in, and blow by out.
I think you really only need a catch can on the "fresh air" side of the PCV system, but I don't have a world of experience here.
I am also of the opinion that if your engine has a ton of blow-by, you really need to fix that.
Having said that, my ring gaps are double factory spec just for boost....
If you're seeing oil in the intake piping, it's not from the PCV system, it's from the breather. Which I guess is still part of the PCV system but on the fresh-air side.
When the intake vacuum is low or positive (negative vacuum? Boost!), the crankcase gases vent to the air cleaner ducting, not the intake manifold. This is also when blowby is at its strongest.
So, if you want to install a separator, it should go on the breather side, not the PCV side.
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