Catch can for paxton sc?

Waakeeen said:

Not sure if anyone is looking at this thread but I wanted to get some validation that I have my engine venting correct. As you can see I have an Anderson power pipe replacing the stock vortech intake so I didn’t want to drill a hole in it so I welded a tube to the intake to connect to the catch can. Also I installed a big red BOV and relocated the MAF after the BOV. I’m noticing now that I’m not catching oil like before so I’m wondering if I should tap the Power pipe and seal the other hole to match the stock vortech piece. Let me know what y’all think, thanks! View attachment 73831

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Here is the problem I see. Normally you suck the crankcase from drivers side using manifold vacuum. This si why on a normal set up you put the catch can on the driver's side. And then normally it draws the clean air into the crankcase from the passenger side from the intake after the MAF. This is a normal system where there is vacuum present. Now, while your car is at idle or light throttle it will continue to work the same. When you go into boost is where you are going to encounter issues. If you have the passenger intake side drawing air from the intake after the MAF and before the SC your system will work as normal and reverse itself while under boost. This is where you are going to need a catch can on the passenger side also. Without any vacuum the pcv valve will not open and it will not flow as normal. In your situation, under boost, you will have pressure at both ends of the system and no escape for crank case gases to go unless the internal pressure of the motor exceeds the amount of boost you are making. Either way you won't catch any oil on the passenger side with the PVC system fully intact. Maybe a little bit under boost. Either way you need to be able to vent the crankcase under boost or you're going to start blowing out seals and stuff.

My suggestion, remove the PCV valve from inside the drivers side valve cover. Put a breather on each side and buy an oil cap breather from CFM. This will give you three points of exit for any positive crank case pressure. You wont need catch cans and you will never get any oil into your SC or intake.

Option 2: You can just move the passenger side intake connection to a point before the the SC and after the MAF, keeping the passenger side can and adding a drivers side can. This will work and the system will flow in both directions depending on manifold pressure or vacuum. This still may introduce oil into the SC or intake tract if any gets by the catch cans.

Option 3: You can leave the system the way it is and add a CFM oil cap breather with check valve and a catch can to the drivers side. This way, while under boost, any crank case pressure can be relieved through the breather cap. This is probably the least desirible IMO.

Personally I would go with my first suggestion.

Awesome, I like the idea of not having to worry about forgetting to drain the catch can. So question, the p/s and the d/s will use breathers "what brand would you recommend" also what do I about the port going into the intake manifold on the d/s after I remove the PCV? Just making sure this is the oil cap breather you mention: https://www.c-f-m.com/performancepa...ther-Kit-for-2002-2017-Mustang-GT-847p86.htm?

You can get any brand breathers that you can clamp on. I use K&N. You just have to get one 3/8" and one 5/8" clamp on style. Yes that is the oil cap breather you want. You will have to close up the ports on the manifold and intake tube. To remove the PVC valve under the valve cover is pretty easy too. I ended up cutting through the baffle and then cutting it out of the little tube. Then I just bent the tube back up and bent the baffle back. easy peasy.

BUT, before you commit to this route there are always a couple of downsides. First off you may get some occasional oil drippage when the filters get saturated with oil. I just tend to wipe them every time I'm under the hood. The second and most important draw back is that because it only vents when there is pressure instead of flowing all the time, it does not work as efficiently at removing fuel vapor and what not out of the crank case gases so you will get more shit dissolved in your oil. This will lead to quicker viscosity breakdown and shorten the length of your oil life. I just tend to change my oil more frequently. That is full disclosure.

Oh wow okay good points there, I'm still learning new things apparently lol. So would it be okay to just to add the oil cap breather as a precaution and leave everything else as is? I mean the car runs greats idles perfect I just was wondering if my setup could be better.

The oil cap breather is a must either way. Leaving it set this way would bother me but as long as you have the cap breather for an outlet I can't see anything that would lead to anything catastrophic. You're still sucking oil vapor into your motor from the drivers side though. Don't let my disclosure dissuade you, I've been running breathers on my motors for the last 4 decades. Best way to go IMO.

I actually ordered all the breathers last night, I said screw it let me try it and see how it goes. Worse thing I have a little bit of oil drip and more frequent oil changes. The car is strictly weekends and occasionally the track. So how soon would change your oil, can you tell by looking at it?

Waakeeen said:

I actually ordered all the breathers last night, I said screw it let me try it and see how it goes. Worse thing I have a little bit of oil drip and more frequent oil changes. The car is strictly weekends and occasionally the track. So how soon would change your oil, can you tell by looking at it?

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I usually go 3k-4K miles or 6 mos. depends on if she is seeing any track time. If you can smell fuel when you check your dipstick it’s been too long.

Here’s a thought too. When you cap your intake ports make sure they are secure. Regular vacuum caps like I use aren’t gonna work once you have positive manifold pressure.

I was thinking of using rubber caps with hose clamps, thanks for the advice! I'm going big with forged block, heads, etc and needed to get the little things out the way before swapping everything. lol

This is an old post!

I ended up using a breather on the oil filler cap on the passenger side and a catch can on the driver side.

So installed the oil cap breather took it for a drive did some WOT and notice oil sprayed coming from the oil cap, is that normal?

Waakeeen said:

So installed the oil cap breather took it for a drive did some WOT and notice oil sprayed coming from the oil cap, is that normal?

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The filter and internal baffles from the breather cap should eliminate oil mist. Do you have breathers on the valve covers too? did you remove the pcv valve from the cam cover? Some drippage is normal as the filter gets saturated with oil but I've never had any spray or mist. Every once in a while I have seen some smoke emanating from a breather when I cut the engine off immediately after a beating.

I actually ended up using catch cans on both sides and eliminating the pcv. Do you think it could be a bad breather?

Here is where I see an issue. Both your passenger and drivers side vents are attached to your intake after the blower. When your not under boost it has three points including the oil cap breather to exit your engine. Once you go into boost, not only are the two vents left without any vacuum, you are actually adding pressure to the crankcase through those cam cover vents. Now, not only is your piston blowby being forced out the one outlet, you are also adding boost pressure which is raising the volume and velocity of crankcase ventilation. Operationally it should be fine but if you want to eliminate the oil spray use 3 breathers. Ditch the pcv system all together. In fact you are bleeding boost into the crankcase instead of the cylinders. Granted it's probably not enough to make a difference but just saying.

Status update got all 3 breathers on no more spray! Lol thanks a lot for the info!

Waakeeen said:

Status update got all 3 breathers on no more spray! Lol thanks a lot for the info!

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No problem, glad you got her squared away. You may get some drippage as the filters get saturated but I usually just give them a quick wipe every time I have the hood open. And they will need the occasional replacement. But I think the 3 breather set up is the only way to go on a boosted car.