Built a Catch Can - Page 2 - PeachParts Mercedes-Benz Forum

mach4 · #16 08-26-2012, 12:26 AM

Quote:

Originally Posted by Graham

The discussion the cyclones came from was a Canadian diesel smart car forum... The oil is drained via a tee in the dipstick tube.

If I'm understanding correctly, instead of condensing out the oil on a substrate (in my case stainless steel wool), they are relying on cyclonic flow to drive the oil to the walls of the chamber - is that the theory? So oil drains down and "clean air" exits to the top. Right?

I wonder if we've got enough air flow (blowby) to get the desired effect.

Thanks

ROLLGUY · #17 08-26-2012, 12:31 AM

While surfing the D D threads, I would have normally passed by this thread because of the title. However, seeing mach4 as the author, I knew it had to be something cool and worth looking at! I was correct. As usual, nice work!

disqo · #18 08-26-2012, 09:19 AM

Want to build another and sell it? Just let me know...

Graham · #19 08-26-2012, 10:42 AM

Quote:

Originally Posted by mach4

If I'm understanding correctly, instead of condensing out the oil on a substrate (in my case stainless steel wool), they are relying on cyclonic flow to drive the oil to the walls of the chamber - is that the theory? So oil drains down and "clean air" exits to the top. Right?

I wonder if we've got enough air flow (blowby) to get the desired effect.

Thanks

Yes, that is how cyclone works. I used to design this sort of thing way back when. In your your case, it seems you rely on oil mist droplets impinging on the wire mesh, coalescing and dripping to bottom. Given that you have space, not a bad design.

Gas flow would be low, so that is probably why the cyclones are so small in diameter. But I imagine BMW/Land Rover did their homework.

They use similar devices on small aircraft engines like this one (M20):

But their competition doesn't think much of the M20 and has one more like yours

On the smart cdis, they tried mesh type separators, but had trouble in cold weather - I think they located them outside of engine compartments and the oil got thick and blocked flow.

daddi · #20 08-26-2012, 10:57 AM

I think i have to quote Shakespeare "Much a do about nothing". I think you guys just wasted a lot of time fixing a problem almost no one knew existed. If the engine is building up residue from the breather in the intake manifold it's not a design flaw! it's because the engine is worn. Through 25 years of fixing i've come to trusting the guys that have done this a 100 years longer.

Graham · #21 08-26-2012, 11:29 AM

Quote:

Originally Posted by daddi

I think i have to quote Shakespeare "Much a do about nothing". I think you guys just wasted a lot of time fixing a problem almost no one knew existed. If the engine is building up residue from the breather in the intake manifold it's not a design flaw! it's because the engine is worn. Through 25 years of fixing i've come to trusting the guys that have done this a 100 years longer.

MB did know about this and on the W123 installed a separator that was integral to the air cleaner. On my 85, the separator (located in centre of the air cleaner) has a drain at bottom that returned oil to the sump. Some others were of different design, but all had a means of separating oil. I trust MB too and they had thought of this

In the case of Mach4, he has installed the engine in a different car and can't fit in the stock air cleaner. So he needs to emulate the original MB thinking and find a way of separating the oil mist.

In the case of the smart CDI I mentioned, there is an intercooler and it loses efficiency when it gets coated or filled with oil (even on low mileage cars). In that case MB seemed to forget that a separator was needed!

suginami · #22 08-26-2012, 01:15 PM

Quote:

Originally Posted by Graham

In the case of Mach4, he has installed the engine in a different car and can't fit in the stock air cleaner. So he needs to emulate the original MB thinking and find a way of separating the oil mist.

Oh, this is interesting. I didn't realize Mach4 had stuffed an MB diesel into another car.

Any pics of the car, Mach4? If not, what kind of car is it and how is it driving?

Graham · #23 08-26-2012, 01:20 PM

Quote:

Originally Posted by suginami

Oh, this is interesting. I didn't realize Mach4 had stuffed an MB diesel into another car.

Any pics of the car, Mach4? If not, what kind of car is it and how is it driving?

In his first post, first sentence

Quote:

I've got a California version OM617.952 in my 107 and since I completed the swap, I've been just dumping the raw valve cover vapor directly into the air intake

As 107 owner too, I would like to know how it has worked out (any links?)

suginami · #24 08-26-2012, 01:23 PM

Quote:

Originally Posted by Graham

In his first post, first sentence

As 107 owner too, I would like to know how it has worked out (any links?)

Thanks.

sixto · #25 08-26-2012, 01:42 PM

Quote:

Originally Posted by Graham

They use similar devices on small aircraft engines like this one (M20):

But their competition doesn't think much of the M20 and has one more like yours

They criticize each others' designs but no one has plumbed them in parallel to see which collects more liquid oil.

Dang, those things are pricey!

Sixto
87 300D

mach4 · #26 08-26-2012, 02:26 PM

Quote:

Originally Posted by suginami

Oh, this is interesting. I didn't realize Mach4 had stuffed an MB diesel into another car.

Any pics of the car, Mach4? If not, what kind of car is it and how is it driving?

The build thread is here - 380SL Diesel Conversion Project

There is also a website at SLDiesel

It runs great. Better than I expected.

charmalu · #27 08-26-2012, 02:38 PM

Sixto, did you see the price for the P-51 Mustang? $999

.
I know Co`s have to jump through Hoops with the FAA etc... so it will raise the cost a bunch.

My 85 doesn`t have the tube in the pan either, I just run it into the U-Tube like the 78/79 w116 300SD.

I have the engine out at the moment, maybe I ought to grab a pan off one at PNP or one of my spare engines. then use a seperator from a 82/83 240D and run the drain to the pan. all the 240D seperators I have seen in the yards are an oily mess, maybe this is because of the inlet/outlet hoses getting old and leaking and lack of maintenance.

Mach4 seperator looks like it is a larger design than the 240 one and maybe less pressure inside it and more efficient?

Then there is the old Draft Tube that has been used for ever.

Charlie