Custom Catch Can/PCV Breather Help
02-19-2017, 10:16 AM
#1
Custom Catch Can/PCV Breather Help
Working on a tuck and shave atm and I'm wanting to eliminate some lines off the intake manifold since I have a lot of other stuff on there now. Looking to put a pair of bungs in the valve cover to replace the PCV valve and breather spit up. Not well versed in this area, and can't seem to find the info I'm after, so thought I'd ask around.
As for placement, does a catch/breather tank have to be equal height with the valve cover, or can it be slightly above, or below? I'm considering having a custom tank made and two spots currently fit my criteria: under the cross member beam - connected to the front of the cover, or under the wiper cowl next to the cabin filter - running the lines from the side of the cover & through the wall.
My initial thoughts are the lower placement would just result in oil pouring in to the tank with no reason, and with the higher placement, it not being actually pushed in to the tank, or running back.
Also, for the tank itself, would it need to be a split tank? One portion for pcv breathing, another for catching oil, or would the pressure and oil simply vent/catch no differently if it was all one chamber? Doesn't seem like it would make a difference to me since there is no differentiation between what each bung line is doing.
Car is an AP1 Turbo.
Any help appreciated, thanks.
As for placement, does a catch/breather tank have to be equal height with the valve cover, or can it be slightly above, or below? I'm considering having a custom tank made and two spots currently fit my criteria: under the cross member beam - connected to the front of the cover, or under the wiper cowl next to the cabin filter - running the lines from the side of the cover & through the wall.
My initial thoughts are the lower placement would just result in oil pouring in to the tank with no reason, and with the higher placement, it not being actually pushed in to the tank, or running back.
Also, for the tank itself, would it need to be a split tank? One portion for pcv breathing, another for catching oil, or would the pressure and oil simply vent/catch no differently if it was all one chamber? Doesn't seem like it would make a difference to me since there is no differentiation between what each bung line is doing.
Car is an AP1 Turbo.
Any help appreciated, thanks.
02-19-2017, 10:36 PM
#2
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I'm also watching this as I'm recently turbo and looking at the same. What I don't get is I understand how to hook it up, however after I send out of the PCV valve hose from the valve cover on one side, do you just plug off the port on the intake end for that hose or? It looks as if I put one side from pcv and the other back to the intake (putting the catch can in the middle) it would still have vacuum in the catch can to the intake and not relieve any pressure.... I learned I had a bad pcv fitting when I first took the car out, gave it some fuel, let off to change gears, heard a funny sound and stopped. The cars RPM's were going up and down sitting at idle... I opened the hood and saw it blew the pcv valve hose off! So could you go from pcv valve to a vented can and just cap off the spot for the pcv on the intake manifold and be good to?
02-26-2017, 06:18 PM
#4
Honda needs to follow emissions rules so thats how the stock system is designed to work. You dont care so just let the breather and PCV puke into a can of some sort thats vented to atmosphere. You dont even need a can if you dont mind puking onto the street though oil on the ground is dangerous for traction. Working systems tend to have a downhill to the can. Turbo cars tend to blow oil out both the breather and pcv but N/A cars tend to only blow out the PCV if the stock hose routing is used. Blow by creates crank case pressure which gets out through the PCV/breather. Some of the oil sloshing around in the valve cover follows the escaping vapors. If your obsessed with shave/tuck weld flat stock over the PCV/breather and put a bung or two near the firewall. Keep in mind the higher the bung placement the less oil will escape. Honda put them on the top for a reason. If you put the bungs too low oil will pour out of the valve cover. Bungs in the rear will puke when on the gas and bungs in the front will puke on the brakes which is better since you aren't wide open making blow by when your on the brakes...............You could just go dry sump.
Last edited by Dead Serious; 02-26-2017 at 06:23 PM.
04-04-2017, 10:59 PM
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You need to decide what the car's purpose will be. Emissions legal or not? Pure performance? Define performance...on a road circuit, the s2k has a problem with spewing oil, especially from the pcv port during fast right-hand sweepers. On a tight slalom/autocross course this shouldn't be a problem. Likewise, straight ahead drag races also shouldn't be a problem.
All cars benefit from an oil catch can by reducing the crap that goes through the intake manifold from the pcv and breather ports. It's important. Read this: Buying the RIGHT catch can for your vehicle | eBay
There's actually quite a bit of information to be gleaned from other sources, as well. It's not overly simple...if you wanna do it right. The engine needs to breath. Venting to atmosphere is simplest, but a performance gain can be had if you keep negative pressure (vacuum) in the crank case. Positive pressure there fights the pistons down stroke and tries to blow past seals at the crank, etc.
Keep in mind that a forced induction car has different needs as the pressure inside the IM goes from varying degrees of vacuum to positive pressure, which obviously affects the ability to provide suction for the original setup.
Don't make the mistake of buying a cheap can that lacks a divider inside the can. I was supplied such a can with my kitcar...kit...and I will be monitoring it to see if it can do what it should. I doubt it and expect most vapours and even liquid oil makes it to the can to just go in one port and out the other. But my engine is in good shape, so the issue is not a big one, anyway.
Also, yes, it does matter where you put it, as referenced in the article/link, above. As he says, "low and cold" is the best location for the can. Low for the can to function (catch oil) and cold for the best reduction of (by condensation of) vapours back to the IM.
Good luck.
Steve, in the NLs
All cars benefit from an oil catch can by reducing the crap that goes through the intake manifold from the pcv and breather ports. It's important. Read this: Buying the RIGHT catch can for your vehicle | eBay
There's actually quite a bit of information to be gleaned from other sources, as well. It's not overly simple...if you wanna do it right. The engine needs to breath. Venting to atmosphere is simplest, but a performance gain can be had if you keep negative pressure (vacuum) in the crank case. Positive pressure there fights the pistons down stroke and tries to blow past seals at the crank, etc.
Keep in mind that a forced induction car has different needs as the pressure inside the IM goes from varying degrees of vacuum to positive pressure, which obviously affects the ability to provide suction for the original setup.
Don't make the mistake of buying a cheap can that lacks a divider inside the can. I was supplied such a can with my kitcar...kit...and I will be monitoring it to see if it can do what it should. I doubt it and expect most vapours and even liquid oil makes it to the can to just go in one port and out the other. But my engine is in good shape, so the issue is not a big one, anyway.
Also, yes, it does matter where you put it, as referenced in the article/link, above. As he says, "low and cold" is the best location for the can. Low for the can to function (catch oil) and cold for the best reduction of (by condensation of) vapours back to the IM.
Good luck.
Steve, in the NLs
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