only need one catch can-not 2

[Dusty]

I am about to do a catch can for my turbo. today I was daydreeming and I think we can get one can to filter both sides.

I am about to do a catch can for my turbo. today I was daydreeming and I think we can get one can to filter both sides.

CC=catch can
IM=intake manifold
VC=valve cover
red=path of air to IM when not boosting (pvc open)
blue=path of air to intake (pre turbo) when under boost (pvc valve closed)

all you need is to move the pvc valve from the valve cover to just before the intake manifold and then put a tee right after the catch can going to the pre turbo intake

so when not boosting vaccume pulls through the catch can and filters the oil. (just like in turbocruisers set up)

but when boosting the pvc valve closes and the filtered air is sent to pre turbo intake as it is pulled there by vaccume

 

[RavenTai]

I see where you are going with that, using the PCV vales check function like that is good idea, but a modern PCV system is designed to draw fresh air in to the engine (post filter) along with puling crankcase gases out,

your setup will allow crankcase gasses out at all times and prevent any pressure build up in the crankcase witch is the most important task but it may be be as effective at removing water from the engine as there will be no fresh air inlet.

Btw I found this one out the hard way, be careful working with the plumbing around the intake manifold, it already sits in a pocket in the hood blanket, and you do not get much room to route things off that hump without it chafing the blanket.

 

[Dusty]

I didn't think the fresh air thing was even a factor on the safari turbo as with the said system the 2nd take off from the valve cover (there are 2) goes to the pre turbo intake which is also under a vacume (though probably not as much vacume as intake manifold). so both lines leaving the valve cover are under a vacume and thus all the valve cover ever sees is a vacume--there dosen't appear to be any "fresh" air for the valve cover with a turbo.

perhaps it would be good to put a one way valve in the tee line going to the intake tube so that gasses could only go to the pre intake and not from it so that the intake manifold doesnt always pull air from preturbo

My inside hood covering is already all chaffed up

 

[Dusty]

I didn't think the fresh air thing was even a factor on the safari turbo as with the said system the 2nd take off from the valve cover (there are 2) goes to the pre turbo intake which is also under a vacume (though probably not as much vacume as intake manifold). so both lines leaving the valve cover are under a vacume and thus all the valve cover ever sees is a vacume--there dosen't appear to be any "fresh" air for the valve cover with a turbo.

perhaps it would be good to put a one way valve in the tee line going to the intake tube so that gasses could only go to the pre intake and not from it so that the intake manifold doesnt always pull air from preturbo. I guess the problem with this is that it would eliminate this source of fresh air although I dont see this is ever going to be anything but a vacume pulling air from the valve cover. I guess I could hook my boost guage up here and see if there is a positive pressure.

My inside hood covering is already all chaffed up

 

[RavenTai]

the area after the filter but before the compressor will be very close to ambient pressure, only vacuum will be that casued the resistance to flow caused by the air filter and ducting witch should be almost nothing same as it would be in a NA engine. that si why the second PCV hose is moved to that location.

 

[Dusty]

so how about this then

 

[RavenTai]

I like it.

During normal operation the crankcase breaths both in and out, during boost crankcase can still breath out to relieve pressure from blow by and the air going into the pre compressor inlet duct will still pass through the single catch can preventing fouling of the compressor and if installed intercooler.

When sourcing check valves make sure they are of sufficient flow at low pressures, I would use the ID inlet line to the valve cover as a reference, and that make sure it does not take much foreword pressure to open them less than a pound or so?, spring loaded ball check valves meant for a hydraulic system would not do and might allow pressure build up in the crankcase making engine seals work harder or possibly fail

 

[Dusty]

in setting up my turbo i found some small little pvc valves (one way) and used one on my charcoal canister so the canister wouldn't see boost. I wonder if these would work. when I blow into them they seem somewhat more sensitive than the pvc valves on the cruiser. you cant realy see the valve from this pic but you can see where it is from the blue silicone line by the charcoal canister

 

[RavenTai]

I have seen those arround, dont know a hole lot about them other than they are check valves, they should be oil and heat resistant and you say they open easily when blown through that takes care of that last question is will they flow enough, the ones for the vacuum system are kinda small, maybe take a look at the larger ones in the large brake booster vac line, you could probably go the a junk yard and find one in a convient diameter and blow through it and see if they also open easily.

 

[Dusty]

ill go hang out at auto zone and see what they got--they really hate me over there as I always want to go behind the counter and dig through all their stuff looking for the right part