what bore size for the pipes on a oil catch can
01 May 2007, 09:02 AM
#4
Scooby Regular
With the greatest of respect, if you're thinking of fitting a catch tank you need to know why you're doing it. The process of finding out how your existing system works and chewing over the various installation schemes for a catch tank will teach you everything you need to know. i.e. do a search for it.
In brief answer to your actual question though - all the ports on the engine for oil vapours take a 13mm hose - reinforced half inch fluid hosepipe from a hardware or boating store will do it. 9mm is way too small and 15mm is a little too big, but if you're getting an ebay special the closer will be 15mm. Whether you can find 15mm hose or not is another matter, it doesn't seem to be a common size.
In brief answer to your actual question though - all the ports on the engine for oil vapours take a 13mm hose - reinforced half inch fluid hosepipe from a hardware or boating store will do it. 9mm is way too small and 15mm is a little too big, but if you're getting an ebay special the closer will be 15mm. Whether you can find 15mm hose or not is another matter, it doesn't seem to be a common size.
01 May 2007, 12:51 PM
#5
Agree with silent.
Bore size 15mm i used black aquatic water hose, cheap and easy to get. Looks good under the bonnet too. You can get the right elbows and T's you need to suit at the same place.
I went through it all in my engine thread in Projects section, seach in there, diagrams/pictures etc all there for you.
Been on my engine for 3 years now and TMIC was oil free afterwards, so is my front mount.
Good mod imho.
Graham.
Bore size 15mm i used black aquatic water hose, cheap and easy to get. Looks good under the bonnet too. You can get the right elbows and T's you need to suit at the same place.
I went through it all in my engine thread in Projects section, seach in there, diagrams/pictures etc all there for you.
Been on my engine for 3 years now and TMIC was oil free afterwards, so is my front mount.
Good mod imho.
Graham.
01 May 2007, 02:18 PM
#6
Scooby Regular
Yes definitely worth doing. Mine's a green system which simply intercepts the main problem area - the short pipe from crankcase breather which vents into the turbo inlet pipe. I've had a totally clean intake all the way through for the past year, not a spot of oil anywhere. I still have my PCV connected and all I did with the rocker cover breathers was get hold of another PCV valve from a breaker's yard and stick it in there so it's one way traffic i.e. the rocker covers can draw fresh air out of the inlet pipe, but can never vent anything back. Works perfect and zero emissions.
01 May 2007, 04:52 PM
#7
Scooby Regular
Agree with silent.
Bore size 15mm i used black aquatic water hose, cheap and easy to get. Looks good under the bonnet too. You can get the right elbows and T's you need to suit at the same place.
I went through it all in my engine thread in Projects section, seach in there, diagrams/pictures etc all there for you.
Been on my engine for 3 years now and TMIC was oil free afterwards, so is my front mount.
Good mod imho.
Graham.
Bore size 15mm i used black aquatic water hose, cheap and easy to get. Looks good under the bonnet too. You can get the right elbows and T's you need to suit at the same place.
I went through it all in my engine thread in Projects section, seach in there, diagrams/pictures etc all there for you.
Been on my engine for 3 years now and TMIC was oil free afterwards, so is my front mount.
Good mod imho.
Graham.
Trending Topics
01 May 2007, 06:21 PM
#8
http://tinypic.com/1fbz38
https://www.scoobynet.com/projects-4...e-started.html
The whole mega thread, go to # 210 and #218.
The story of my life for 15 months!
Hope this helps.
It is simpler than it looks, just a bit cramped.
Graham
https://www.scoobynet.com/projects-4...e-started.html
The whole mega thread, go to # 210 and #218.
The story of my life for 15 months!
Hope this helps.
It is simpler than it looks, just a bit cramped.
Graham
01 May 2007, 07:21 PM
#10
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I got a kit off e-bay that uses 13mm (1/2 inch) pipe. Fitted as supplied but later changed the hoses to Samco to get the blue hose to match the rest of the plumbing
01 May 2007, 07:24 PM
#11
That is why people do the cheap mod.
Keeps the intercooler internals clean and unblocked, also keeps the octane rating of the fuel constant as oil in the inlet air will drop the rating dramatically = detonation = big bang = big $$$$$$$$$$
Graham
Keeps the intercooler internals clean and unblocked, also keeps the octane rating of the fuel constant as oil in the inlet air will drop the rating dramatically = detonation = big bang = big $$$$$$$$$$
Graham
01 May 2007, 10:29 PM
#13
Scooby Regular
Depends how you're doing it - 'green' or venting out. After chewing over the problem for a long time, I couldn't see how the system could possibly work properly by just joining the pipes together into a catch tank with a big bore vent on it. The crankcase is supposed to have a vacuum drawing the fumes out. If you vent this out to atmosphere you've lost that entirely, that's a fact. You will still have some positive pressure in the crankcase, but not what you should have to ventilate it properly, hence not enough to draw fresh air in from the inlet pipe. I still don't really understand what the incentive is to vent it all out. A green system like mine works perfectly well, in fact IMHO better and there's no chance of smelling engine fumes at standstill. It catches ALL the problem oil on boost, is totally clean and closed off, vents the engine exactly as Subaru intended, what's not to like?
I made my present catch tank out of an aluminium cyclists water bottle with a 1/2" brass hose tail screwed into each end and fish tank filter foam in between. Works perfect and even comes with a handy bottle cage for attachment to the bulkhead. When I need to empty it, I just pull the hoses off and unscrew the lid - it's one in, one out.
I made my present catch tank out of an aluminium cyclists water bottle with a 1/2" brass hose tail screwed into each end and fish tank filter foam in between. Works perfect and even comes with a handy bottle cage for attachment to the bulkhead. When I need to empty it, I just pull the hoses off and unscrew the lid - it's one in, one out.
01 May 2007, 10:39 PM
#14
Depends how you're doing it - 'green' or venting out. After chewing over the problem for a long time, I couldn't see how the system could possibly work properly by just joining the pipes together into a catch tank with a big bore vent on it. The crankcase is supposed to have a vacuum drawing the fumes out. If you vent this out to atmosphere you've lost that entirely, that's a fact. You will still have some positive pressure in the crankcase, but not what you should have to ventilate it properly, hence not enough to draw fresh air in from the inlet pipe. I still don't really understand what the incentive is to vent it all out. A green system like mine works perfectly well, in fact IMHO better and there's no chance of smelling engine fumes at standstill. It catches ALL the problem oil on boost, is totally clean and closed off, vents the engine exactly as Subaru intended, what's not to like?
I made my present catch tank out of an aluminium cyclists water bottle with a 1/2" brass hose tail screwed into each end and fish tank filter foam in between. Works perfect and even comes with a handy bottle cage for attachment to the bulkhead. When I need to empty it, I just pull the hoses off and unscrew the lid - it's one in, one out.
I made my present catch tank out of an aluminium cyclists water bottle with a 1/2" brass hose tail screwed into each end and fish tank filter foam in between. Works perfect and even comes with a handy bottle cage for attachment to the bulkhead. When I need to empty it, I just pull the hoses off and unscrew the lid - it's one in, one out.
sounds good, dont think i will vta, do you have any pics of your set up?
what version impreza have you got?
any pics of what pipes to use would be good, i have a my00 classic
02 May 2007, 12:33 AM
#15
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got similar system to silent running pcv valve in rocker circuit. put mine just where it joins inlet pipe so easy to get at (just in front of inlet manifold).
then there is a small rubber elbow coming off crankcase going to inlet pipe (behind inlet manifold) pull off inlet pipe and turn through 180 degrees use 1/2" straight connector and 1/2" hose and route to catch tank. take a second hose from catch tank to half way down chassis. job done.
ken
then there is a small rubber elbow coming off crankcase going to inlet pipe (behind inlet manifold) pull off inlet pipe and turn through 180 degrees use 1/2" straight connector and 1/2" hose and route to catch tank. take a second hose from catch tank to half way down chassis. job done.
ken
02 May 2007, 09:19 AM
#16
Scooby Regular
got plenty of pics but the best way to see it is with the inlet manifold off, which I don't have photos of, well not clear ones anyway.
As Graham pointed out above, aquatic stores are your friend when it comes to catch tank plumbing. Get your hose and joiners from there - you can usually find reinforced hose pipe with a criss-cross pattern of reinforcing fibres. One step up from this, and less likely to go soft with engine bay heat is the same kind of hose but with an outer coloured jacket. I found mine at a yachting suppliers. Mine's a v4 by the way.
Anyway, my main findings are that the two rocker cover vents are not the problem area at all. It made no difference to how much oil I collected whether I had them connected to the tank or not. As Scooby-k says, just stick a spare PCV valve in the side of your inlet pipe where the rocker cover breathers draw air from, so that they can't push air back into the inlet pipe. Leave the PCV line that goes from crankcase breather to under the throttle body alone. Take the short joining hose that goes from the crankcase breather into the inlet pipe and either turn it round and extend it with a joiner and hose to your catch tank, or just remove it entirely and stick your new hose directly down onto the crankcase breather outlet.
Decide what you want to do with the fumes, either vent them along a pipe out of the catchtank or to keep full efficiency run a pipe back to the inlet pipe port that you just disconnected.
As Graham pointed out above, aquatic stores are your friend when it comes to catch tank plumbing. Get your hose and joiners from there - you can usually find reinforced hose pipe with a criss-cross pattern of reinforcing fibres. One step up from this, and less likely to go soft with engine bay heat is the same kind of hose but with an outer coloured jacket. I found mine at a yachting suppliers. Mine's a v4 by the way.
Anyway, my main findings are that the two rocker cover vents are not the problem area at all. It made no difference to how much oil I collected whether I had them connected to the tank or not. As Scooby-k says, just stick a spare PCV valve in the side of your inlet pipe where the rocker cover breathers draw air from, so that they can't push air back into the inlet pipe. Leave the PCV line that goes from crankcase breather to under the throttle body alone. Take the short joining hose that goes from the crankcase breather into the inlet pipe and either turn it round and extend it with a joiner and hose to your catch tank, or just remove it entirely and stick your new hose directly down onto the crankcase breather outlet.
Decide what you want to do with the fumes, either vent them along a pipe out of the catchtank or to keep full efficiency run a pipe back to the inlet pipe port that you just disconnected.
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