The definitive "How do I catch can?" thread.
#162
Stainless steel
The chambers consist of walls which are 5mm narrower than the can, and go from floor to ceiling, the issue with a can such as the one below is that when the contents reaches the baffle the can is effectively full.
In this design, how does blowby get past the oil/wall? This is why multiple holes or vertical slots are common.
Dann
The chambers consist of walls which are 5mm narrower than the can, and go from floor to ceiling, the issue with a can such as the one below is that when the contents reaches the baffle the can is effectively full.
In this design, how does blowby get past the oil/wall? This is why multiple holes or vertical slots are common.
Dann
#163
Stainless steel
The chambers consist of walls which are 5mm narrower than the can, and go from floor to ceiling, the issue with a can such as the one below is that when the contents reaches the baffle the can is effectively full.
ni
In this design, how does blowby get past the oil/wall? This is why multiple holes or vertical slots are common.
Dann
The chambers consist of walls which are 5mm narrower than the can, and go from floor to ceiling, the issue with a can such as the one below is that when the contents reaches the baffle the can is effectively full.
ni
In this design, how does blowby get past the oil/wall? This is why multiple holes or vertical slots are common.
Dann
#166
Im not knocking yours either. Catch can design is pretty awkward for the reasons we are discussing, I respect your opinion way far enough to take your criticism seriously.
This whole can is only 700cc, really for street car guys with bolt on mods, not for racecars/built engine 20+psi folk.
But for real, do you think it has appeal in the states, worth figuring out international shipping and posting on US pages? Sells here for 300aud, around 230usd with everything.
Dann
This whole can is only 700cc, really for street car guys with bolt on mods, not for racecars/built engine 20+psi folk.
But for real, do you think it has appeal in the states, worth figuring out international shipping and posting on US pages? Sells here for 300aud, around 230usd with everything.
Dann
#167
Im not knocking yours either. Catch can design is pretty awkward for the reasons we are discussing, I respect your opinion way far enough to take your criticism seriously.
This whole can is only 700cc, really for street car guys with bolt on mods, not for racecars/built engine 20+psi folk.
But for real, do you think it has appeal in the states, worth figuring out international shipping and posting on US pages? Sells here for 300aud, around 230usd with everything.
Dann
This whole can is only 700cc, really for street car guys with bolt on mods, not for racecars/built engine 20+psi folk.
But for real, do you think it has appeal in the states, worth figuring out international shipping and posting on US pages? Sells here for 300aud, around 230usd with everything.
Dann
#170
My setup works well enough on the street, but at the track the catch can filled up and oil made its way to the intake at the turbo. So I'll have to take the intercooler out to try cleaning it. I get a lot of crank case pressure at the track it seems, oil weeps out of the valve cover oil cap, and my dip stick pops up after a few hard laps. I've read through the crank case pressure threads, this thread, and I'm still not sure what I should do lol.
#172
Are there any more ports on that catch can? Kinda a weird place to put it, usually if you have only one can it's between the intake manifold and valve cover...
I would disconnect the PCV while at the track, cap the intake manifold line and run both valve cover vents to the catch can. Probably put a breather filter, instead of routing it back to the intake by the turbo. Should give you double the flow, without modding the valve cover. Might still fill with oil, maybe drain it between sessions. At least it won't be dumping into the turbo.
You've also got a FWD valve cover, all in the wrong orientation. It's easy to see how it could dump oil under acceleration. I really want to trade my escort cover for a miata one for that reason.
I would disconnect the PCV while at the track, cap the intake manifold line and run both valve cover vents to the catch can. Probably put a breather filter, instead of routing it back to the intake by the turbo. Should give you double the flow, without modding the valve cover. Might still fill with oil, maybe drain it between sessions. At least it won't be dumping into the turbo.
You've also got a FWD valve cover, all in the wrong orientation. It's easy to see how it could dump oil under acceleration. I really want to trade my escort cover for a miata one for that reason.
#173
Are there any more ports on that catch can? Kinda a weird place to put it, usually if you have only one can it's between the intake manifold and valve cover...
I would disconnect the PCV while at the track, cap the intake manifold line and run both valve cover vents to the catch can. Probably put a breather filter, instead of routing it back to the intake by the turbo. Should give you double the flow, without modding the valve cover. Might still fill with oil, maybe drain it between sessions. At least it won't be dumping into the turbo.
You've also got a FWD valve cover, all in the wrong orientation. It's easy to see how it could dump oil under acceleration. I really want to trade my escort cover for a miata one for that reason.
I would disconnect the PCV while at the track, cap the intake manifold line and run both valve cover vents to the catch can. Probably put a breather filter, instead of routing it back to the intake by the turbo. Should give you double the flow, without modding the valve cover. Might still fill with oil, maybe drain it between sessions. At least it won't be dumping into the turbo.
You've also got a FWD valve cover, all in the wrong orientation. It's easy to see how it could dump oil under acceleration. I really want to trade my escort cover for a miata one for that reason.
#174
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I would disconnect the PCV while at the track, cap the intake manifold line and run both valve cover vents to the catch can. Probably put a breather filter, instead of routing it back to the intake by the turbo. Should give you double the flow, without modding the valve cover. Might still fill with oil, maybe drain it between sessions. At least it won't be dumping into the turbo.
#176
I drift the car so I'm constantly on throttle hard, then off, back on, and so forth. My understanding was that without the pcv I could potentially pull oil / oil vapor into the combustion chamber and lower octane as a result. That's the reason I felt the pcv was necessary, but maybe I misunderstood.
#178
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Yeah, just cap off the pcv valve on the intake for the track.
It won't be pulling vacuum on crank off throttle any more, but you need more vent so that seems like the priority for track usage.
My system is routed like yours except I have a catch can between vc and pcv. Also my fresh air side has been opened up a bit and larger line on that side. I don't have problems with dip stick poping out at 14psi manifold pressure, but I don't track either. Before I opened up the fresh air side the dip stick would pop up.
It won't be pulling vacuum on crank off throttle any more, but you need more vent so that seems like the priority for track usage.
My system is routed like yours except I have a catch can between vc and pcv. Also my fresh air side has been opened up a bit and larger line on that side. I don't have problems with dip stick poping out at 14psi manifold pressure, but I don't track either. Before I opened up the fresh air side the dip stick would pop up.
#179
You will have more oil venting if you just disconnect the pcv line btw.
I know that this pretty ugly right now but it works on the track runing 15psi, i am getting no oil on the catch can and since the photo have removed the can drain line. Again no oil on the catch can after 1-1/2" hours, i will be doing 3 hours track on the 27th
esentially i left the pcv line with the can as before for dd and added the following on to the exhaust side vent:
1) installed a second air inlet and cover like the oem piece on the center chamber steel cover.
2) made (6) 1/4" holes between the top of the center chamber and the bottom of the exhaust chamber.
3) welded the eom vent shut.
4) cut a 1/2"x 2" slot on the top of the exhaust chamber .
5) built a third chamber over the exhaust chamber.
6) put a -10 vent fitting and hose.
I know that this pretty ugly right now but it works on the track runing 15psi, i am getting no oil on the catch can and since the photo have removed the can drain line. Again no oil on the catch can after 1-1/2" hours, i will be doing 3 hours track on the 27th
esentially i left the pcv line with the can as before for dd and added the following on to the exhaust side vent:
1) installed a second air inlet and cover like the oem piece on the center chamber steel cover.
2) made (6) 1/4" holes between the top of the center chamber and the bottom of the exhaust chamber.
3) welded the eom vent shut.
4) cut a 1/2"x 2" slot on the top of the exhaust chamber .
5) built a third chamber over the exhaust chamber.
6) put a -10 vent fitting and hose.
#180
Does anyone else have problems idling after reworking the crankcase ventilation system? I did enlarge the tiny hole on the driver's side and welded a threaded -10AN fitting to the valve cover. Since I'm still running N/A, I put a small breather filter on the fitting for now.
on the passenger side I'm running full -10AN lines as well. They are routed from the valve cover through a metal check valve, into a catch can, and from there to the inlet manifold
the problem is: even with the idle screw fully closed and the idle valve unplugged, it still idles at around 3000 RPM. The engine is simply pulling too much air through my ventilation system. My current plan is to put a restrictor into the line between the valve cover and the catch can. Thus I hope to choke the engine enough to keep the idle down where it belongs. At the same time this would hinder PCV, though.
on the passenger side I'm running full -10AN lines as well. They are routed from the valve cover through a metal check valve, into a catch can, and from there to the inlet manifold
the problem is: even with the idle screw fully closed and the idle valve unplugged, it still idles at around 3000 RPM. The engine is simply pulling too much air through my ventilation system. My current plan is to put a restrictor into the line between the valve cover and the catch can. Thus I hope to choke the engine enough to keep the idle down where it belongs. At the same time this would hinder PCV, though.