Catch can not catchin so much...
Race Director
Joined: Dec 2000
Posts: 19,304
Likes: 85
From: San Diego CA
The CH can, like other polycarbonate-bowl cans, is temperature-limited to about 120 degrees F. If you are not careful about where you mount it, you can easily experience leakage of unfiltered air into your PCV line - not a good thing.
In addition, that CH can is most likely a particulate filter, not a coalescing filter. Particulate filters can trap liquid oil (as you have seen), but are poor traps for aerosol oil, whether you reverse flow or not.
If you do have this filter mounted up front, in a cool area, consider adding a true coalescing filter (like the Watts in my article) after it. (and don't reverse flow direction through the element)
In addition, that CH can is most likely a particulate filter, not a coalescing filter. Particulate filters can trap liquid oil (as you have seen), but are poor traps for aerosol oil, whether you reverse flow or not.
If you do have this filter mounted up front, in a cool area, consider adding a true coalescing filter (like the Watts in my article) after it. (and don't reverse flow direction through the element)
Le Mans Master
Joined: Feb 2003
Posts: 6,683
Likes: 144
From: Memphis Tennessee
The CH can, like other polycarbonate-bowl cans, is temperature-limited to about 120 degrees F. If you are not careful about where you mount it, you can easily experience leakage of unfiltered air into your PCV line - not a good thing.
In addition, that CH can is most likely a particulate filter, not a coalescing filter. Particulate filters can trap liquid oil (as you have seen), but are poor traps for aerosol oil, whether you reverse flow or not.
If you do have this filter mounted up front, in a cool area, consider adding a true coalescing filter (like the Watts in my article) after it. (and don't reverse flow direction through the element)
In addition, that CH can is most likely a particulate filter, not a coalescing filter. Particulate filters can trap liquid oil (as you have seen), but are poor traps for aerosol oil, whether you reverse flow or not.
If you do have this filter mounted up front, in a cool area, consider adding a true coalescing filter (like the Watts in my article) after it. (and don't reverse flow direction through the element)
Last edited by ALLEGRO; Dec 1, 2007 at 11:53 PM.
Race Director
Joined: Dec 2000
Posts: 19,304
Likes: 85
From: San Diego CA
From my catch can article:
Maximum temp. in battery compartment during 20 minute ride home on a 75 degree day: 132°F
This exceeds your can's maximum temperature rating, so be careful....
Maximum temp. in battery compartment during 20 minute ride home on a 75 degree day: 132°F
This exceeds your can's maximum temperature rating, so be careful....
Last edited by Dave68; Dec 3, 2007 at 10:17 AM.
Team Owner
Joined: May 2004
Posts: 26,345
Likes: 232
From: SoCal
...with flame-suit on...
I am using a CH catch can complete with the coalescing stone in place. It is installed in "reverse flow" configuration and immediately following it I have a plastic fuel filter inline. All of this is AFTER the OEM PCV system.
I get enough oil in the bowl to be concerned, about the same as mentioned in this thread. I find it amazing that there is this much oil getting by and GM is not more concerned. All my reading suggests that the oil is drawn up during deceleration. My car is not driven very hard and I have the MN6. One suggestion was that it was the derivitive of high rpm and light throttle opening. I don't think I fit that scenario much in my normal driving.
All in all, we all need a system to stop the oil from making the inside of the intake. I intended to move UP to the EE type cans, but mine appears to work well.
...flame suit on......FIRE AWAY.
I am using a CH catch can complete with the coalescing stone in place. It is installed in "reverse flow" configuration and immediately following it I have a plastic fuel filter inline. All of this is AFTER the OEM PCV system.
I get enough oil in the bowl to be concerned, about the same as mentioned in this thread. I find it amazing that there is this much oil getting by and GM is not more concerned. All my reading suggests that the oil is drawn up during deceleration. My car is not driven very hard and I have the MN6. One suggestion was that it was the derivitive of high rpm and light throttle opening. I don't think I fit that scenario much in my normal driving.
All in all, we all need a system to stop the oil from making the inside of the intake. I intended to move UP to the EE type cans, but mine appears to work well.
...flame suit on......FIRE AWAY.
DH
Le Mans Master
Joined: Dec 2005
Posts: 8,475
Likes: 332
From: Port Arthur, Texas 77642
Melting Slicks
Joined: Sep 2003
Posts: 2,458
Likes: 105
From: Northville Michigan
In another post, a Forum member told of how he had mounted a catch can from the valve cover outlet to a point low on the passenger-side frame rail. At the end of each track session his catch can was full of oil.
For those who have catch cans in the valve cover to throttle body line, take a look at their inlet, and be sure it is higher than the valve cover's outlet point.
Last edited by Pumba; Dec 2, 2007 at 10:19 AM.
Team Owner
Joined: May 2004
Posts: 26,345
Likes: 232
From: SoCal
[FONT="Tahoma"][SIZE="3"][COLOR="Blue"]I agree with Andy on this point. As I mentioned earlier in this post, I believe that you should mount the inlet for the catch can for the hose coming from the valve cover higher than its outlet point on the valve cover to prevent syphoning of the oil out of the valve cover.
I DO KNOW that Andy believes the position of the outlet is most important. In other words the outlet right from the valve cover is geting oil thrown right at it where as it is much harder for the oil to get to the top of the filler cap. He may also have a baffle in the cap???
DH
Race Director
Joined: Mar 2005
Posts: 10,053
Likes: 17
If you run the car hard i.e. track days or races and still have the oil in the manifold problem after catch can installation you may want to think about restricting oil flow to upper end. This is a problem in most wet sump LS engines.
A lot of racers are using Smith Bros. .040 restriction pushrods (part # 581R) in either stock length (7.400) or if you have milled heads and .040 head gasket a 7.350 length pushrod. These are chrome moly 5/16" x .083 wall.
A lot of racers are using Smith Bros. .040 restriction pushrods (part # 581R) in either stock length (7.400) or if you have milled heads and .040 head gasket a 7.350 length pushrod. These are chrome moly 5/16" x .083 wall.
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Le Mans Master
Joined: Sep 2006
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From: Phoenix AZ
2021 C4 of the Year - Modified Finalist
catch can
why not design a catch can that lays horizontal and the drain has a tube that fits over the dipstick tube, or weld a y end of a tube to the dipstick tube, and let the oil recycle itself?
this isn't really very hard to do.
You will just have to find a nice convenient place to keep the dipstick under the hood when you are not checking the oil
this isn't really very hard to do.
You will just have to find a nice convenient place to keep the dipstick under the hood when you are not checking the oil
