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Fresh turbo motor, catch can?

4EyedTurd

New member
Joined
Sep 29, 2009
Location
Waco,Tx
I'm drawing close to having a running car soon and with a completely fresh motor would it be worth it to run a catch can instead of a pcv? It seems that a catch can is a bandaid for a worn out motor. Granted, mine is fresh but I plan on running plenty of boost thru it. WWYD?
 
I experimented with a catch can this last weekend on a road trip. The catch can allowed increased crankcase pressure and I blew oil out the dipstick tube. With the factory PCV I had good venting but may have consumed oil through the vacuum line going to the elbow. I think the factory pcv is probably better for engine longevity.
 
Uh, if you blew out your dipstick tube it's not the catch can that's your issue......

Also, running oil into the intake system isn't doing wonders for longevity either. In fact, it's probably worse.

Yes, run a catch can. The sperators on the car are pretty lame at best. With a decent catch can like a pro vent you'll notice a cleaner intake system. Remember oil lining the guts of the IC are lowering it's abilities substantially, and lowering your octane rating. There is nothing good, and many things bad with running oil into the intake system and compression chambers.

I run VTA with a CC, and at elevated boost on a motor with 160psi compression average, I'm not blowing out the dipstick. Running it from a CC into the intake will be even less pressure in the crank case.

Long story short, get a catch can. Don't rely on 70s technology to separate your oil vapors.
 
Uh, if you blew out your dipstick tube it's not the catch can that's your issue......

Also, running oil into the intake system isn't doing wonders for longevity either. In fact, it's probably worse.

Yes, run a catch can. The sperators on the car are pretty lame at best. With a decent catch can like a pro vent you'll notice a cleaner intake system. Remember oil lining the guts of the IC are lowering it's abilities substantially, and lowering your octane rating. There is nothing good, and many things bad with running oil into the intake system and compression chambers.

I run VTA with a CC, and at elevated boost on a motor with 160psi compression average, I'm not blowing out the dipstick. Running it from a CC into the intake will be even less pressure in the crank case.

Long story short, get a catch can. Don't rely on 70s technology to separate your oil vapors.

^This.
 
Catch can is not a band aid, unless you intend it to be. For higher than stock output (elevated boost/ Rpms) it is a good thing . You need to be certain that the I/O of the CC are larger than the stock 14mm ID Volvo hose, especially for VTA. The Provent is a proven performer. Search & you will find several builds using it.
 
I run VTA with a CC, and at elevated boost on a motor with 160psi compression average, I'm not blowing out the dipstick. Running it from a CC into the intake will be even less pressure in the crank case.

Long story short, get a catch can. Don't rely on 70s technology to separate your oil vapors.

Is your catch can vented to the atmosphere or do you have the outlet hooked up to the factory port in the intake? I had my catch can in-line with the factory PCV and somehow still had increased crankcase pressure. With the factory PCV alone, my crankcase pressure is under control but I lost 1/4th of a quart of oil. I'm also not sure where the oil is going, its either condensing in my intercooler or being burned. However, when I removed my intake manifold it was squeaky clean inside which leads me to believe that there must be a few quarts in my intercooler.

On the other hand, maybe the real problem isn't PCV, its also possible that my piston rings are allowing excessive blow-by
 
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I have tried both. VTA is vent to atmosphere, where I'm venting from the head and the crank case to a catch can. You really need to vent from both if running VTA.

I've also run through a catch can, to the intake, to run a closed system under vacuum. I found this still pulled in oil at WOT runs. I'm slowly fabbing up a catch can that should work better to allow this to be used again, without the oil.

If you're losing that much oil, something is up. I'm burning very little oil even running VTA. I don't need to top it off between 7000k oci's.
 
What are your thoughts on the little vacuum line that runs from the factory pcv elbow to the intake? I replaced all my vac lines with silicone hoses and the pcv hose has oil seeping through it. Is it possible that im sucking a lot of oil vapor through that? The only time i lose oil is on the highway between 2500-3000 rpm, and when im on the highway i try to keep out of boost
 
Some people find it negligible, but when I deleted it, my catch can filled up considerably faster. It's still pulling vacuum at idle, so it will be pulling in those fumes. The upside is less vapor vented, the downside is it's going right to the head and valves. One could in theory run a CC in line with that, or just delete it.
 
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