200tdi Crank case breather - plan to restrict the air flow?

[Maverik]

As title suggests, 

I've recently noticed since installing the VGT turbo to my aged 200tdi, that there's a little more oil pull through into the air filter housing as per the standard factory set-up - I used to get some oil in the filter can top section with the original turbo, but since the normal operating inlet pressure is a fair bit higher now +1bar, I think it must be dragging more through from the crank case, I replaced the breather pot with the Ali sports one which hasn't helped either. 

Short term I've just put the breather air outlet into a bottle with a perforated top section, and I had a mind of just installing a catch tank - 

So having a bit of time to mull the problem over, I was thinking that the increased air flow from the higher inlet pressure was actually pulling the oil ladened blow by gas through the cyclone before it got chance to separate out.... so why not slow it down? - so then though why not just put an orifice into the breather gas/air pipe at the filter end... anyone any thoughts?

Mav

[Bowie69]

A bit if wire wool stuffed into the breather pipe pre-breather pot could well work?

Was sometimes all they had on older cars.

[Maverik]

Yeah tried that before and it might have helped a bit but not much.

[ianmayco68]

I've had this problem on mine after fitting the uprated chra and upping the boost kept checking the turbo but no sign of oil round that , then thought I was going mad  , then realised it must be coming up the breather . Did think if a washer type of thing but thicker pushed into the breather pipe the catch tank end to reduce the air flow and give the oil chance to hit the sides and run back to the tank .

[Maverik]

12 minutes ago, ianmayco68 said:

I've had this problem on mine after fitting the uprated chra and upping the boost kept checking the turbo but no sign of oil round that , then thought I was going mad  , then realised it must be coming up the breather . Did think if a washer type of thing but thicker pushed into the breather pipe the catch tank end to reduce the air flow and give the oil chance to hit the sides and run back to the tank .

Pretty much exactly what I was thinking, as long as the the breather isn't restricted enough to cause back pressure in the crank case - that what I'm just deliberating, how small can I make the orifice without backing up my breather.

[ianmayco68]

I've got an Allisport catch tank like you , I've not looked but can you buy pressure release valves like used on air lines then fit it to the tank so if it does build up then it will vent automatically as a safe guard , no nothing about them but how does a turbo dump valve work and could that be adapted ? Just a quick look on fleabay found this 

https://www.ebay.co.uk/itm/Adjustable-Universal-25mm-Recirculating-Bov-Dump-Blow-Off-Diverter-Valve/263332927694?hash=item3d4fdd98ce:g:hJQAAOSwHUhaEX1m

haven't looked into it much as I'm still trying to make up my mind whether to rework the 200tdi fit a vnt turbo and do other bits or fit a bmw m57 3.0d engine , as I'm not getting any younger and this will have to last till I'm too old to drive it as this will be the last mod with a new chassis I do to the 110 .

[Maverik]

The breather needs to be free flowing as much as possible, as its not designed for any kind of pressure, if you block it you know about it as pretty much every engine seal starts to blow oil out, done it once accidentally.

So this is what I've done coiled a pieceof silicone hose up to make an orafice... see what happens...

[Maverik]

Hmmm, so going for a drive I had further thoughts, as the engine would be sucking effectively a vacum on the crank case, I think my initial logic of slowing air down is wrong, making an orafice would only create a potential pressure drop over it meaning a higher pressure on the crank side which is very much not desired, so I've pulled put the thing I put in, and re thinking my wee problem.

[Sigi_H]

if there is coming to much oil from the breather in the cylinderhead there are only 2 options.

1. Engine is worn and blowby gasses take oil with them.
2. Breather (which ist a cyclone) is bad.

Edited August 9, 2020 by Sigi_H

[Maverik]

12 hours ago, Sigi_H said:

if there is coming to much oil from the breather in the cylinderhead there are only 2 options.

1. Engine is worn and blowby gasses take oil with them.
2. Breather (which ist a cyclone) is bad.

1. Yes

2. I don't think I've ever seen a land rover 200/300tdi cyclone breather actually do what it was meant to do properly. Oil carry over in the 300tdi's in pretty well documented and 200tdi heavy breathing also.

This isn't a new topic by far, I just had some thoughts about the restriction idea, but then decided that it wouldn't be such a great idea - so back to the standard solution of a catch tank for now.

The oil seems to condense out of the air in the hose from the breather to the air box - I've got some Chinese catch tank thing of ebay which I'll plug in as an intermediary oil block, I can either have it vent to atmosphere or put in another hose to the filter box, I like the idea of the closed air loop, just as long as it doesn't drag oil into the inlet side.

 

An interesting topic actually is heat exchanger efficiency when contaminated with oil, I read some info a while ago with regard to water based heat exchangers - I think it might have been in the boiler context, that saying even a slight oil contamination of coolant water can cause a massive efficiency drop in the heat exchange due to oil coating of the radiator internal surface causing a thermal block. - I wonder if you see similar thing with an intercooler...

https://innecs.nl/en/contamination-of-steam-by-oil/#:~:text=Consequences of steam contamination&text=Heat conduction of oil is,failure occurs (Figure 3).

[Sigi_H]

In the breather is some metallic wool to condense more oil. It tends to get frozen (with moisture foam in the oil) in wintertime and do the mentioned restriction. Not good.

A catch tank is a good compromise for sure. It is good to vent it to the air box, because this will apply some vacuum to the engine

[Maverik]

16 minutes ago, Sigi_H said:

In the breather is some metallic wool to condense more oil. It tends to get frozen (with moisture foam in the oil) in wintertime and do the mentioned restriction. Not good.

A catch tank is a good compromise for sure. It is good to vent it to the air box, because this will apply some vacuum to the engine

Regarding vacuum - I was thinking about this, I guess having a slightly negative pressure crank case is beneficial with regard to oil seals less so if you're submerged in water though (which is a rare occurrence).

On 8/7/2020 at 12:32 PM, Bowie69 said:

A bit if wire wool stuffed into the breather pipe pre-breather pot could well work?

Was sometimes all they had on older cars.

 

On 8/7/2020 at 1:40 PM, Maverik said:

Yeah tried that before and it might have helped a bit but not much.

 

[Sigi_H]

Vacuum will only be some mbar ... really less

I connected my gearboxes on the airbox too. If the gearbox breather hoses are going down and are open, this will suck a lot more water, when the gearbox is being shocked with cold water

Edited August 10, 2020 by Sigi_H

[western]

There's no moving parts in the cyclonic breather 

 

[Snagger]

5 hours ago, Sigi_H said:

In the breather is some metallic wool to condense more oil. It tends to get frozen (with moisture foam in the oil) in wintertime and do the mentioned restriction. Not good.

 

Only on the pre-Tdi engines.

[Snagger]

4 hours ago, western said:

There's no moving parts in the cyclonic breather 

 

The diaphragm moves.  I can hear it open on my 200Tdi as it is run to the intake of the air filter housing and echoes up the snorkel.  It sounds like a muffled plastic drum being struck every so often.

[western]

Yes only the diaphragm moves, I didn't know there was anything inside until I watched that video. 

[ianmayco68]

So basically if you've got a allisport one fitted like me and Maverik , which uses just a baffle , being as it dosen't shut off like the original one could that be causing more oil than normal to be pulled through into the air intake system ?

[western]

I would think only if the engine is worn & the oil rings are allowing excess to get past. 

I know my engine is good, as I rebuilt it with new pistons/rings/.020. rebore 2 years ago, just done a filter change & I still get about a teaspoon full of oil in the air cleaner filter & turbo intake where the breather hose connects to air cleaner inlet, I just wipe it out every 6000 miles, it doesn't or hasn't affected the engine.

 

[Mo Murphy]

I get the same as Ralph on the same servicing schedule, which is reassuring for me.

Mo

[Maverik]

10 hours ago, ianmayco68 said:

So basically if you've got a allisport one fitted like me and Maverik , which uses just a baffle , being as it dosen't shut off like the original one could that be causing more oil than normal to be pulled through into the air intake system ?

yeah... that's what I've now been thinking 

[Maverik]

10 hours ago, western said:

I would think only if the engine is worn & the oil rings are allowing excess to get past. 

I know my engine is good, as I rebuilt it with new pistons/rings/.020. rebore 2 years ago, just done a filter change & I still get about a teaspoon full of oil in the air cleaner filter & turbo intake where the breather hose connects to air cleaner inlet, I just wipe it out every 6000 miles, it doesn't or hasn't affected the engine.

 

Thats actually quite helpful Ralph as that's actually all I was really getting (maybe a little more) just pooling in the recess of the filter sponge seal area... but since putting the Alisports can on I know got a fair bit of residue on the inlet bell for the turbo compressor too and it would cough a fairly blue cloud in the morning start up. My engine has a fair few miles on her and probably not long for a rebuild, but I don't think she's breathing excessively.

I'm going to keep my ad hoc catch bottle on with this Alisports thing, and I might change it back to a standard breather, I would prefer to have no oil pull through, so will think on it a bit more.

[Maverik]

Found on Land Rover UK forums - thought it complimented the thread quite well.

 

[Peaklander]

So that one has a diaphragm/valve and a spring but it’s not accessible to check or repair. How would you know that a replacement has the same construction?

[Maverik]

57 minutes ago, Peaklander said:

So that one has a diaphragm/valve and a spring but it’s not accessible to check or repair. How would you know that a replacement has the same construction?

cough cough *Britpart* cough... you dont, it probably does, but it might not work properly. - I've got one downstairs. Stupidly didn't check the manufacturer before ordering.

I guess you could try sucking on it hard, should activate the flap - I'll go try... - no that wont work... but if you block the other holes you can feel the flap closing - i.e. if you suck onto a vacuum - if you look on the video you see one opening is larger than the other - this is the key. 

I've just purchased the valve assembly as used on Td5's... going to pop that in and see what it does. (LLN100140L).