Catch cans do they really work? Bullitt

[Elp_jc]

Yeah, the driver's side is a waste of money. I wasn't going to install one, but turns out my engine is drinking a little bit of oil (like 1/4-qt in 3K+ miles), so bit the bullitt and bought the FP one, since it fits like factory. I was expecting a freaking FP decal, but no dice. Oh well. Installed it at 4,300+ miles, so plugs and everything else should still be relatively clean. Having said that, the inside of the air filter tube was quite dirty. Not oily dirty, but dirt dirty. It obviously didn't happen with the air filter in place, so probably just filthy before assembly. Curious if others have noticed the same thing.

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[FreePenguin]

Being 20yrs old doesn't mean it doesnt still apply. Nothing has changed with PVC systems. Where do you think the oil that gets sucked through goes? Into your take and onto the back of your valves. Where heat cooks it. Having a dual fuel system helps with the valves but does 0 for the intake.

its the small things that we appreciate right? I also didn't get a ford performance with my catch can either. everyone else sends me them and I have multiples but I still like getting at least one.

come on ford.

 

[Schwerin]

The amount of oil going into catch/PCV will be dependent on how well you rings are sealed. Is your car burning oil??

Fuck the EPA. I have run this setup for 10k miles (passenger side) will zero issues or messes. Kill two birds with one stone w/ crank case ventilation. ;).

That's just stupid. Every time I see a setup like this all I think "old guy from the 50's that has no idea how modern engine systems works, or a Honda owner that went to Pepboys."

The hose is connected back to your intake after the MAF, so the CPU is accounting for that bit of airflow in it's numbers. It's air the computer interantly accounts for in it airflow number claculations, so by doing this you're basically making your AF numbers be slighlty incorrect, and you've added a hole to your system that air can escape the sealed system out of. Air should not be able to ENTER your engine any way BUT your intake tube, and escape it anyway EXCEPT your exhaust.

 

[garagelogic]

To me, the question is not "do they work" but "are they needed"? My opinion is they are not and are a waste of money.

 

[IamCDNJosh]

I think there's a general misconception of what catch cans really do. I have the Ford Performance one on my Mustang (port injection) and no catch can on my F150 (direct injection) as ford doesn't make one.

Seems that there is a belief that a catch can will prevent valve coking. What I haven't seen is any evidence to support this other than showing what the catch can got. The reason I say this is there's no proof to show that 100% of the vapor is caught, therefore any that does make it through could still contribute to buildup on the intake valves.

Catch cans were originally invented to attempt to remove this vapor which if introduced in the intake tract could then lower the octane in the A/F mixture leading to pinging or knocking. That is the ONLY reason I have one on my mustang and I expect to only realize those benefits during a track day.

Anyways, debate and discuss, I'd love to see evidence that this is the end all be all solution to eliminate valve coking on a DI engine but I haven't been able to find it.

 

[Elp_jc]

One thing is for sure: A good catch can, like the FP, is NOT going to hurt anything, so other than having to spend the money for one, there's no drawback. I wasn't going to install one unless there was oil consumption on my engine... and there's a little, so decided to buy one at about 4K miles, and installed it a few weeks ago.

 

[Schwerin]

I think there's a general misconception of what catch cans really do. I have the Ford Performance one on my Mustang (port injection) and no catch can on my F150 (direct injection) as ford doesn't make one.

Seems that there is a belief that a catch can will prevent valve coking. What I haven't seen is any evidence to support this other than showing what the catch can got. The reason I say this is there's no proof to show that 100% of the vapor is caught, therefore any that does make it through could still contribute to buildup on the intake valves.

Catch cans were originally invented to attempt to remove this vapor which if introduced in the intake tract could then lower the octane in the A/F mixture leading to pinging or knocking. That is the ONLY reason I have one on my mustang and I expect to only realize those benefits during a track day.

Anyways, debate and discuss, I'd love to see evidence that this is the end all be all solution to eliminate valve coking on a DI engine but I haven't been able to find it.

I don't think I've seen ANYONE say it prevents it 100%. The point is not to PREVENT but to MINIMIZE the effects from the blow-by and delay them. For example instead of needing to have your valves cleaned at 120k, you instead have it at 150k. Also, during that time you're delaying the other issues like loss of MPG and performance. All of which can easily make up for the cost of a catch can(not to mention the added small environmental benefit of not burning oil, and the interest you save in the bank on the $$ that would be needed to clean the IM and valves).

If you really wanted to PREVENT it all, you could always run a system with 2 filters, the 2nd with a tighter filter than the 1st to catch even more vapor. At that point though you're likely not going to see enough return on it unless you either do a LOT of track work, or you are daily driving the car for like 400-500K miles. Just like how you could also in theory have a dual filter oil system so that you dont have to change your oil as much, but it's not very much added in the return of the development and install price for the system.

Is 0 filter fine? yes.
Is 1 filter better than 0 filter? yes.

 

[GT 550]

That's just stupid. Every time I see a setup like this all I think "old guy from the 50's that has no idea how modern engine systems works, or a Honda owner that went to Pepboys."

The hose is connected back to your intake after the MAF, so the CPU is accounting for that bit of airflow in it's numbers. It's air the computer interantly accounts for in it airflow number claculations, so by doing this you're basically making your AF numbers be slighlty incorrect, and you've added a hole to your system that air can escape the sealed system out of. Air should not be able to ENTER your engine any way BUT your intake tube, and escape it anyway EXCEPT your exhaust.

Maybe I'm missing something but not sure how this set up is a problem as he appears to be just venting his valve covers to atmo. If it was still plumbed back into the intake then it'd be a problem ie leak.

As for the ECU accounting for increased airflow after the AFM where's the air coming from? The vac is applied to a sealed system so the airflow is negligible. For airflow sufficient to affect the mixtures you'd need a leak ie hole in the block or sump.

 

[Schwerin]

Maybe I'm missing something but not sure how this set up is a problem as he appears to be just venting his valve covers to atmo. If it was still plumbed back into the intake then it'd be a problem ie leak.

As for the ECU accounting for increased airflow after the AFM where's the air coming from? The vac is applied to a sealed system so the airflow is negligible. For airflow sufficient to affect the mixtures you'd need a leak ie hole in the block or sump.

Follow the tube that he removed. It DOES go back to the intake, the system factors that air circulation into it.

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