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Oil Catch tank?

29222 Views 93 Replies 22 Participants Last post by  Dawmill
Read over and over the threads, what is the best one out there that does the job?
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A good thread this, some very interesting points Spectre. As some one who has a catch tank fitted (currently inline) its one i've been watching closely.

It never ceases to amaze me how many knowleable people there are on this site and how friendly it is with such free exchange of infomation. :)

Spectre, you mentioned a pre butterfly crank case breather still being conneted. Where exactly is this, and could you elborate more on this please? Also, i currently have my catch tank only connected to one crank breather hose, as in the photos above, where is the other hose located please? I take it these are the two that are being talked about in posts above being connected by a external t-piece be for going into the catch tank?

Sorry for all the questions, just trying to get my head around some of this as i'm unfortuanatly clued up on the kv6 engine. (must get my homework done!!)

Many thanks, Andy.
what did you use to block the inputs to the manifold?
what did you use to block the inputs to the manifold?
I actually used chemical metal in the ends of the original pipes (cut off about 1 inch from the end) but I cannot recomend this to anyone else since if it comes loose it is strong enough to hole a piston. After I had done it I thought I should not have but I have used chemical metal to fill holes in throttle butterflys before and its been fine, its incredibly strong stuff.

Cut the pipes and leave the manifold end in the manifold then block it somehow, using a short length of rubber hose with a bolt in it would be a much better idea than mine (3k miles so far though, touch wood).

I'll get some pictures when I get a chance and highlight the other breather but its the larger hose entering the top of the throttle infront of the butterfly section. Not really a problem since this area is never in Vacuum but it will still let some crud in. The one after the throttle is the bad one and blocking this makes the engine feel more responsive with more engine braking making the throttle feel more accurate.
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god, i can't wait to return from london next monday now to fit the catch tank :stir: looks like this thread will be ongoing....
Sorry if i've upset anyone, just wanted peoples best opions.
god, i can't wait to return from london next monday now to fit the catch tank :stir: looks like this thread will be ongoing....
Sorry if i've upset anyone, just wanted peoples best opions.
Lol, this is a good thread you started, seems there are quite a few variations of the set up, post some pics Dean when you have done yours :yup:
The second line, returning to the inlet is unecesary and is only there to keep the green party happy. You also still have the pre butterfly crank case breather still conneted, its not so bad as its never in vacuum but it will still let 100+degree dirty air into your inlet charge.

If it were not for some drag strips and track days requiring either a 1 litre catch tank or a sealed system (as in standard) you could just let the crank case breath stright to the atmosphere. My Metro VVC was just connected straight to the atmosphere and nothing but the tinyest amount of oil ever came out, didnt clean the engine bay more than once a year.
in the picture which pipe is it thats not needed? cheers
Lol, this is a good thread you started, seems there are quite a few variations of the set up, post some pics Dean when you have done yours :yup:

Variations of set-up yes,
Basic principle remains the same,
Evacuating crank case pressure,
NOT allowing the gas that’s been vented to a catch can back into the engine, its that simple.
Various routes can be taken to achieve this but most of what I have seen so far shows people are just creating a loop back into the engine with a catch can in the middle.
Looks nice but you’re really defeating the object
Dean the masher tanks are no longer available.

Some use the baffle and some dont.

Its there to catch the oil vapour as it comes in and to prevent it from being sucked straight back out.

Heres a pic of what we used for baffle

if any shards of metal fall off your scouring pad, they will make a pretty good mess of your bearings shells!
if any shards of metal fall off your scouring pad, they will make a pretty good mess of your bearings shells!
Well not really ...... the worst that would happen is it could get into the inlet manifold/head+cylinders (not the engine) If you dont have it connected to vent. (ie connected back to the manifold)
Looking at that though i doubt very much that would happen. That stuff looks quite good
Variations of set-up yes,
Basic principle remains the same,
Evacuating crank case pressure,
NOT allowing the gas that’s been vented to a catch can back into the engine, its that simple.
Various routes can be taken to achieve this but most of what I have seen so far shows people are just creating a loop back into the engine with a catch can in the middle.
Looks nice but you’re really defeating the object
Thats where it gets confusing.

A guy on another forum done this the other way and and after quite a while found that the tank had no oil in it whatsoever.

So can someone say where the oil has gone and why bother fitting a oil catch tank that collects no oil.

Its all very confusing to Joe Public.:)
Thats where it gets confusing.

A guy on another forum done this the other way and and after quite a while found that the tank had no oil in it whatsoever.

So can someone say where the oil has gone and why bother fitting a oil catch tank that collects no oil.

Its all very confusing to Joe Public.:)
That doesnt surprise me. When you disconnect the pipes and vent them to air, the oil vapour from the crankcase isnt being drawn through under engine vacume anymore, it just vents under its own pressure. So you cannot exspect to get the same amount of oil comming through as before.
Thats where it gets confusing.

A guy on another forum done this the other way and and after quite a while found that the tank had no oil in it whatsoever.

So can someone say where the oil has gone and why bother fitting a oil catch tank that collects no oil.

Its all very confusing to Joe Public.:)
Yeah you pretty much dont get any oil in there unless there is an engine problem. It is for this reason that some drag strips and track day tracks require a catch tank and not, as some are using it as an oil seperator tank.

You can just block the inlet pipes up and vent the crank case to fresh air if you like, you dont even need one of those poxy breather filters as there is a filer in the rocker cover and the only air it will draw in is when the engine is cooling, a tiny amount of unfiltered air in the crank case wont do any harm to the engine at all.
Well not really ...... the worst that would happen is it could get into the inlet manifold/head+cylinders (not the engine) If you dont have it connected to vent. (ie connected back to the manifold)
Looking at that though i doubt very much that would happen. That stuff looks quite good
It works well dave and when that was removed from the MK1 on inspection there was no shards in the catch tank or in the oil that you see in that photo.

I am sure if any shards were gonna come of the scourers there would at least be one left in the oil.

The scourers had been in the catch tank for over a year.

Saying that i am now understanding the principles of doing it the other way, but what i can say is since having our catch tank installed in this way on the mk1 and the mk2 we dont have loads of oil in the throttle body.

Also when we bought both cars they had loads of oil leaking from the bottom of the oe airbox and on inspection of the new induction piping in that area its now oil free.

Both cars have also been free of vis valve issues since the tanks were fitted but maybe that is just a coincidence and who knows.

I suspect both ways of doing this has its good points but i am sure someone will prove me wrong:)
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It would be good if peeps could see the 2 types of catch tank setups with photos if possible?

I am not sure which way to set up mine, just want to do it the right way
Well not really ...... the worst that would happen is it could get into the inlet manifold/head+cylinders (not the engine) If you dont have it connected to vent. (ie connected back to the manifold)
Looking at that though i doubt very much that would happen. That stuff looks quite good
The reason i mentioned it was because i did exactly the same thing on the scoob and was swiftly informed of my mistake by one of the top tuners on the scene.

Proper rolled up mesh is a MUCH safer option.

I have not looked at the ZS breather system at all yet, but i would assume that its not only setup to "vent", it will "suck" on occasion as well and this can suck swarf back up the pipes on other types of engines...
Yeah you pretty much dont get any oil in there unless there is an engine problem. It is for this reason that some drag strips and track day tracks require a catch tank and not, as some are using it as an oil seperator tank.
Agreed, one of my mates lost a litre of oil due to surge on a pretty aggressive start at elvington :D
The reason i mentioned it was because i did exactly the same thing on the scoob and was swiftly informed of my mistake by one of the top tuners on the scene.

Proper rolled up mesh is a MUCH safer option.

I have not looked at the ZS breather system at all yet, but i would assume that its not only setup to "vent", it will "suck" on occasion as well and this can suck swarf back up the pipes on other types of engines...
What sort of rolled up mesh did you use inside your catch tank?
I had some tight holed metal mesh kicking around at work which i chopped and rolled up to fit, but in the end i removed it as it was taking up valuable space in the can (the more space you have the less regularly you have to empty the damn things)

the best systems feature a "return to sump" setup, but its probably a massive overkill for the ZS`s "problem"

personally i have not made up my mind weather or not its actually a "problem"

oil in the inlets can effect fuel octane and bring on det, but i seriously doubt that these stock engines are mapped aggressive enough for it to be a problem.

i wish i could find some remapping software so i can get inside the ecu and see what's going on :D
I think we are getting mixed up here about the purpose of the catch tank on the 180.
It's not a performance mod, but a preventative mod, to stop or cut down on the amount of oil that gets into the plenum making an abrasive paste that knackers the vis butterfly ball joints resulting in a new plenum being required. Also to try and protect the 2 vis motors.
Of course if it's possible to plumb it so that it does the above AND gives a performance increase then that's to be welcomed. I am going to change mine to vent to air and blank off the 2 TB inlets to see if it makes a difference. Just waiting for the 2 filters to come now.cool2
I think we are getting mixed up here about the purpose of the catch tank on the 180.
It's not a performance mod, but a preventative mod, to stop or cut down on the amount of oil that gets into the plenum making an abrasive paste that knackers the vis butterfly ball joints resulting in a new plenum being required. Also to try and protect the 2 vis motors.
Of course if it's possible to plumb it so that it does the above AND gives a performance increase then that's to be welcomed. I am going to change mine to vent to air and blank off the 2 TB inlets to see if it makes a difference. Just waiting for the 2 filters to come now.cool2
Piccies when you do Alan please!:dddc:

I assume the performance gain folks are reffering too will be something along the lines of- if you allow the catch tank to vent to air instead of simply passing back into the TB- then you'll be getting cleaner air into the engine!!!!!????

Yes/no- have i got the right end of the stick!???

All i'd say regarding that is that you have to be careful WHERE you sight vents- as i did used to have a different system for the breather setup- where it basically vented to air instead of through a catch tank & back into the engine- and you could definitely smell oil/engine vapours coming into the car at times when it was like that!!!!!!!!!

All i can say regarding my catch tank setup is that since fitting n modfying it- i no longer see any liquid oil gathering in the TB- it's free n clear- which should hopefully mean the VIS motors are nice n clean too (seen pics of some that were gunked up to hell n that surely can't be good for em!)
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