Oil breather pipe - valve

[tolsen]

Re: Oil breather pipe - valve

Catch tanks cost an and and a leg and the tanks can't legally be vented to atmosphere. Vent has to be piped to inlet at TIK pipe and the vapours be combusted by engine.

[ethanol-smart]

Re: Oil breather pipe - valve

Catch cost an and and a leg and the tanks can't legally be vented to atmosphere. Vent has to be piped to inlet at TIK pipe and the vapours be combusted by engine.

Yes, and the crankcase gases are fuel too. Not burning them will lead to higher fuel consumption. It is not serious to just vent them out from health reasons either.
It wouldnt surprice me at all if a better and less simple oil separation feature in the Smart have been designed and considered, but was cynically saved in on in the last stage.
I read somewhere that they made an improvement inside the valve cover sometime 1999, so there have been issues, thats for sure.

[tolsen]

Re: Oil breather pipe - valve

My engine is now loosing just below 2 centilitres of oil in 10000 km, this is with the mark 3 separator fitted. I presume some of this oil is lost directly to combustion chamber from cylinder walls but also lost as oil vapour or oil mist that passes through my separator and condenses inside charge cooler. There is never much oil in its lower part and I do therefore think the air flow pushes the oil through charge cooler and into inlet manifold. I may proceed in engineering an oil mist condenser but feel I have already reached the point of diminishing returns. Losing only 2 centilitres in 10000 km is not a lot.

[Thrumbleux]

Re: Oil breather pipe - valve

Yes, and the crankcase gases are fuel too. Not burning them will lead to higher fuel consumption. .

Does the Lambda detect the oil burning as fuel? Then lean off the 'real' fuel? In which case it is running on lowered octane 'fuel' - cue retarding of ignition timing....

About Thrumbleux idea, well, that might be a reason too, on a petrol!
And an explanation for the worse performance regarding oil consumption on the petrols too.
But isnt this then the case for all turboengines? And excessive oil consumption on modern turbo cars is very unusaul as long as there havent been any severe mistreat of the oil or similar.

Size could be an issue here, the smart componentry being the smallest around. Just a guess though.

Anyway how did you want to test your theory? With a large checkvalve connected to atmoshere, securing no vacuum before throttle?

Yep, as soon as I can find someting suitable. Ideally a reed valve. It will also require a filter.
Going to have a look at something that might work today.

[tolsen]

Re: Oil breather pipe - valve

Have you considered improving the oil separator built into rocker cover?





I am a wee bit baffled by the design of the baffle chamber.

I am wondering if oil separation will be significantly improved if breather gases were arranged to pass through the whole length of the space rather than only half?

Perhaps one can add demister mesh between the baffles to encourage oil to separate out from oil mist?

[ethanol-smart]

Re: Oil breather pipe - valve

An off the shelf solution from Mann&Hummel?: http://www.google.com/url?sa=t&rct=j...0maAAS0gpVd0xQ
Anyone seen this one on another car so we know what to look after in the scrapyards...?

M&H writes that on high turboloads, there is also blowby through the turbo bearings down the oil return from the turbo..

[ethanol-smart]

Re: Oil breather pipe - valve

Does the Lambda detect the oil burning as fuel? Then lean off the 'real' fuel? In which case it is running on lowered octane 'fuel' - cue retarding of ignition timing....



Size could be an issue here, the smart componentry being the smallest around. Just a guess though.



Yep, as soon as I can find someting suitable. Ideally a reed valve. It will also require a filter.
Going to have a look at something that might work today.

The lambda is corrected as the gases are full of hydrocarbons.
Yes the octane-rate might also be lowered with high oil content in the air, another reason to feed our engines with E85 instead :-)

[ethanol-smart]

Re: Oil breather pipe - valve

Have you considered improving the oil separator built into rocker cover?





I am a wee bit baffled by the design of the baffle chamber.

I am wondering if oil separation will be significantly improved if breather gases were arranged to pass through the whole length of the space rather than only half?

Perhaps one can add demister mesh between the baffles to encourage oil to separate out from oil mist?

Perhaps, it looks like that maybe the designers gave up the idea when they realized that the inside of the valve cover of the stressed Smart in a very small engine compartment almost without any ventilation, is not the best place to hope for some effective condensation....
There could be a lot of stuff inside this cover, but maybe it was found not to work as intended and then only it was removed from the scoop.

[tolsen]

Re: Oil breather pipe - valve

An off the shelf solution from Mann&Hummel?: http://www.google.com/url?sa=t&rct=j...0maAAS0gpVd0xQ
Anyone seen this one on another car so we know what to look after in the scrapyards...?

M&H writes that on high turboloads, there is also blowby through the turbo bearings down the oil return from the turbo..

ProVent is too expensive so not an option for those with a shoe string maintenance budget. Another problem is difficulty finding a suitable place for it due to its rather large size.
I also guess it is unsuitable for cold weather operation. The Canadians have reported freezing up of catch tanks, obviously due to water or steam in blow by gasses unless the catch tank is small and fitted very close to engine. ProVent will have similar problems.

Where do you read "on high turboloads, there is also blowby through the turbo bearings down the oil return from the turbo"?

Above will be the case if piston seals are leaking but I can't find any reference to that in above document specifically to high turbo load.

[ethanol-smart]

Re: Oil breather pipe - valve

Did you find a price for the ProVent? How much?

The size and needed vertical orientation and position might be a problem in our case, I agree.

About turbos, see page 3:

In turbocharged
engine applications,
air can also make its way
into the crankcase through
the oil return pipe of the turbocharger.

This air is contribution to the total blow-by gas volume, and needs also to be taken care of.

About temperature,
M&H means to mount their product on the engine block, and I understod that many catch tank solutions are more mounted in one of the wheelhouses of the Smart.
If we want the self emptying feature of the ProVent, the unit must be higher mounted than the level of the oil in sump at least, and this should be a bit warmer in winter time.
However, M&H claims the operating field of (-35 °C to 120 °C).

I found a better pdf about ProVent:

https://www.mann-hummel.com/group/upload/doc/HBCHACUaaBi.pdf

Seems to be a smaller variant, ProVent 100. 146mm and diam 84mm Hmmm
What can it cost? (Found ProVent 200 for about 150$)


For some more general info about crankcase ventilation, this might come in handy:

http://en.wikipedia.org/wiki/Crankcase_ventilation_system

[tolsen]

Re: Oil breather pipe - valve

ProVent 100 cost around 70 Pounds a year ago when I looked into these issues. Order from a factor or garage that sells Mann & Hummel filters. I even made a wooden mock up to see if it could be fitted somewhere. Concluded there was no space for it in engine bay of my Cdi so I had to go for a more compact solution.
Beware there are about 4 different versions of ProVent 100 and that it uses a consumable filter insert.

There are other separators that cost a lot less and may be equally effective. Here are three:


BMW cyclone separator, price around 30 Pounds.
Oil separator LH 11151406788
Oil separator RH 11151406789


Landrover Discovery cyclone breather, 12 Pounds from Landyworld.

http://shop.landyworld.co.uk/land-rover-300tdi-cyclone-breather-57-p.asp

My DIY cyclone separator. Material cost less than 50p.

[ethanol-smart]

Re: Oil breather pipe - valve

Thanks a lot for you research, Tolsen!
Yes, we probably dont need those consumables, and by the way, in old times many of these designs where filled full or partly with metal wool (steel for cleaning...), which also are helping condensation.
I think we could find more space in our smarts if we think away the neccesity to mount the thing just next to the outlet of the vavlvecover of our engines.
In many models, there is a good space just right of the engine, where we anyway want to feed back the oil in the disptick tube or similar.
There we have much more possibilities to find a fitting part to a reasonble price.
Considering the high temperatures in the higher parts of the engine compartment of the Smart, I cant see any risk for freezing inside even a 1 meter pipe and a protected oil trap, mounted on the right side of the camchain.
A bit colder position of the oil trap can also be good in order to even better help condensation.
If anyway a problem, there is always the possibiltiy to insulate part of the system.
(I know that some models have an airpump and/or some EGR-system in this volume, but I think most cars havent)
Those BMW and landrover parts looks nice!
Will go a buy some transparent hose now so I can follow whats happening inside on the way to and from my future separator design!

[tolsen]

Re: Oil breather pipe - valve

... Will go a buy some transparent hose now so I can follow whats happening inside on the way to and from my future separator design!

You're off to Biltema then I presume?

[ethanol-smart]

Re: Oil breather pipe - valve

Yep!
Im not long from them here at work...
However, I didnt had time today, will have to take that later..
Btw..I saw from one of your pics some genuine swedish snuff...?
Im I talking to a swede here...?