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Catch can
- Thread starter jayh231
- Start date
fuchsroehre
Active Member
Catch can for the blow by? To catch the carry over oil?
Would be interesting to see what you found? Any pictures?
Thanks.
Would be interesting to see what you found? Any pictures?
Thanks.
jayh231
New Member
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Yeah thats why I was wondering if anyone knew anything about them. I had seen it on a forum, I will try to find it again but its something that would be pretty good to have.
2021DAMRAMMINIT
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Im looking into adding a can to my 21' 2500 6.4 hemi. If someone could help on the size needed to b effective. Had one on my 12' 1500 5.7 hemi. It helped out the response of the motor when u pedal it down. Blow by average was about 3-4oz of oily gunk every month!! I had a 350ml on the 5.7
*Need help on Size Im guessing 750ml on the 6.4?? Plz someone knows
Thx ...
Sent from my SM-G975U using Tapatalk
*Need help on Size Im guessing 750ml on the 6.4?? Plz someone knows
Thx ...
Sent from my SM-G975U using Tapatalk
fuchsroehre
Active Member
I have a catch can on my race car, the size is roughly 500ccm. It has a K&N filter on top and a petcock on the bottom. The blow by gasses (which are combustion gases bypassing the piston rings) come from the crankcase (not the valve cover) perpendicular into the catch can. The size of the hose is about 1.5 inches ID.
When you run a catch can you typically have to empty it once in a while. If you forget it then there will be a mess, maybe more than a mess dependent how your setup is.
The fluid (carry- over) I get out after a race weekend is about 5-10 ounces of fuel/ water/ oil mixture.
Interesting would be to know what the setup is. There are typically 2 circuits, a high and a low pressure circuit. Low pressure is connected to the intake manifold, high pressure to the air filter.
On the low pressure side you do not want to have a leak, that would mess with the running behavior and maybe braking performance (brake booster needs vacuum). A catch-can on the low pressure side could be a potential risk to introduce leaks. Another downside is when the catch can fills up, the engine can suddenly get large amounts of carry over into the intake.
The catch-can and the collected carry over may also freeze in the winter time because it will catch water, too. A frozen breather is not so bad, as long the high pressure passage is still functional while the low pressure side thaws. If the whole breather system freezes you will pop seals out.
The purpose of the catch can on the low pressure side is mitigating oil introduction into the intake manifold. It might be possible that the oil can increase the knock sensitivity of the engine.
It also makes the intake more "dirty". But the "dirt" which is carbon, oil, etc. is normally washed away by the detergents of the fuel. Modern DI engines went back to having injectors in the combustion chamber and intake ports. Older DI engines were missing the injectors in the intake, there the issue was carbon buildup due to the internal EGR which happens when both intake and exh. valves are open at the same time. Exhaust gases make it into the intake and introduce some carbon buildup.
Anyhow, normally the OEM design the breather system well and messing with it introduces unknown issue. I would only do it as an experiment and if I had nothing else to do. Don't try to fix a system which is not broke.
When you run a catch can you typically have to empty it once in a while. If you forget it then there will be a mess, maybe more than a mess dependent how your setup is.
The fluid (carry- over) I get out after a race weekend is about 5-10 ounces of fuel/ water/ oil mixture.
Interesting would be to know what the setup is. There are typically 2 circuits, a high and a low pressure circuit. Low pressure is connected to the intake manifold, high pressure to the air filter.
On the low pressure side you do not want to have a leak, that would mess with the running behavior and maybe braking performance (brake booster needs vacuum). A catch-can on the low pressure side could be a potential risk to introduce leaks. Another downside is when the catch can fills up, the engine can suddenly get large amounts of carry over into the intake.
The catch-can and the collected carry over may also freeze in the winter time because it will catch water, too. A frozen breather is not so bad, as long the high pressure passage is still functional while the low pressure side thaws. If the whole breather system freezes you will pop seals out.
The purpose of the catch can on the low pressure side is mitigating oil introduction into the intake manifold. It might be possible that the oil can increase the knock sensitivity of the engine.
It also makes the intake more "dirty". But the "dirt" which is carbon, oil, etc. is normally washed away by the detergents of the fuel. Modern DI engines went back to having injectors in the combustion chamber and intake ports. Older DI engines were missing the injectors in the intake, there the issue was carbon buildup due to the internal EGR which happens when both intake and exh. valves are open at the same time. Exhaust gases make it into the intake and introduce some carbon buildup.
Anyhow, normally the OEM design the breather system well and messing with it introduces unknown issue. I would only do it as an experiment and if I had nothing else to do. Don't try to fix a system which is not broke.
Drumminguy81
Active Member
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I had a catch can installed on my 08 6.7, I gutted/deleted the CCV filter then ran the return vent line to a catch can and plugged the intake side at the turbo. I was surprised at the amount of oil it would collect that would have been saturating the CCV and/or get blown back into the turbo. There are some pretty lengthy threads on this and the differing opinions of it on one of the other forums. it didnt cause me any trouble other than emptying the catch can at oil changes. But I decided on my 2020 ill just stick to changing the CCV filter at an earlier interval FWIW.