Built a Catch Can - Page 3 - PeachParts Mercedes-Benz Forum

mach4 · #31 08-26-2012, 05:44 PM

Quote:

Originally Posted by disqo

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

It wouldn't do you any good, as this was purpose built for a totally custom application. As has been pointed out, many Mercedes already have an air-oil separator incorporated into their design.

sixto · #32 08-26-2012, 06:01 PM

Here's some info on the conic design - http://us.mg5.mail.yahoo.com/neo/launch?.rand=52h0iutv8r4cq

And the patent itself - Oil separator for a crankcase ventilation system in an internal combustion engine

Isn't most of the oil vapor going to flow straight through?

Sixto
87 300D

mach4 · #33 08-26-2012, 07:14 PM

Quote:

Originally Posted by sixto

And the patent itself - Oil separator for a crankcase ventilation system in an internal combustion engine

Isn't most of the oil vapor going to flow straight through?

That doesn't make any sense. Some oil would be separated, but the efficiency would have to be really low.

Here's the main description of the supposed operation

I guess if it's a primary device, the efficiency doesn't have to be anything special.

Graham · #34 08-26-2012, 07:38 PM

Quote:

Originally Posted by sixto

Here's some info on the conic design - http://us.mg5.mail.yahoo.com/neo/launch?.rand=52h0iutv8r4cq

And the patent itself - Oil separator for a crankcase ventilation system in an internal combustion engine

Isn't most of the oil vapor going to flow straight through?

Sixto
87 300D

That unit is different from the cyclone previously posted. It is hard to see how it works. It seems to be relying on the oil droplets migrating to the outside of the pipe. There will be a velocity profile across the diameter with low velocity at wall and highest in center. You would think that would cause mist in centre to be carried straight through. But they say, the pressure loss causes oil to drop out.

They do say it could be applied as a primary separator indicating that perhaps it is not too efficient.

Graham · #35 08-26-2012, 07:48 PM

Quote:

Originally Posted by mach4

The build thread is here - http://www.peachparts.com/shopforum/diesel-discussion/308791-380sl-diesel-conversion-project.html

There is also a website at SLDiesel

It runs great. Better than I expected.

I recall following the original thread for a while. Congrats on getting it all together. Must be very satisfying.

My 617 diesel and my 107 will remain apart. I don't have those skills

sixto · #36 08-26-2012, 07:52 PM

Quote:

Originally Posted by Graham

That unit is different from the cyclone previously posted. It is hard to see how it works. It seems to be relying on the oil droplets migrating to the outside of the pipe. There will be a velocity profile across the diameter with low velocity at wall and highest in center. You would think that would cause mist in centre to be carried straight through. But they say, the pressure loss causes oil to drop out.

They do say it could be applied as a primary separator indicating that perhaps it is not too efficient.

If it quacks like an expansion valve, maybe there's a drop in temperature along with the drop in velocity and pressure to further promote condensation. I don't buy it any more than you do

Sixto
87 300D

mach4 · #37 10-09-2012, 07:33 PM

As you can see in the image below, the catch can was not as efficient as it should be. Oil is still condensing out in the intake. It's a ton better than before without the catch can, but I think I can do a lot better.

So I rebuilt the catch can using the same sheet metal template, but this time I used a set of baffles to significantly increase the fume path through the catch can. Here it is ready to be loaded with stainless wool and welded up.

Here's the new design showing the path through the can.

And yes, the bottom baffle has notches cut in the bottom to allow oil to flow through to the drain.

JHZR2 · #38 10-10-2012, 01:24 PM

Nice!

What would be a great mod is to build this, with the connections to have a wye into the regular drain, and then pipe the system through this, to the main separator, and then into the drain tube.

Id pay to put one on my 300cd.

mach4 · #39 10-10-2012, 03:46 PM

Quote:

Originally Posted by JHZR2

Nice!

What would be a great mod is to build this, with the connections to have a wye into the regular drain, and then pipe the system through this, to the main separator, and then into the drain tube.

Id pay to put one on my 300cd.

The problem with this idea is that I don't have a "regular separator". The vehicle that this engine is in is a 107 and there is just no room. I built a custom air cleaner to fit the space I have available - which is the reason I built the custom separator as well.

cho · #40 10-11-2012, 07:39 AM

Quote:

Originally Posted by mach4

Hi mach4

do you expect any trouble with crankcase ventilation in due
separator setup air resistance? ... i.e serious blow-by...etc....

Tx

ChO

.

MTUpower · #41 10-11-2012, 08:14 AM

^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

I've got a 240D sep unit on my modified 617-95X which leads to a gatorade bottle filled with fishing line The drain on the 240d unit drains to the oil pan- and the vapor section leads to the gatorade bottle. The bottle does have holes in the top. When first installed the holes were too small and the engine would not produce power- just as Cho suggests to watch out for. I had to make larger holes and the problem went away. After nearly three years I pulled the bottle and there was about 4 ounces of oil liquid in it. (of course I checked it many times in those three years). I did not want a oil coated intake/IC and so no vapor liquid enters the intake at all. No need to plum the vapor section to the intake if you have a second catch can. There is no significant vapor residue in the engine compartment either so I'm happy.

iceman104 · #42 03-15-2014, 02:54 AM

Interested in possibly buying one of these off you. My 85 300sd has a separator and drain hole in oil pan. But some how the oil isnt making its way in the passage way made for it. It end up all in my air filter then draining out a small hole in bottom of oil box and all over the car in enge bay. Is this because a bad separator or do i have ALOT of blow by? What can i do please help.

cho · #43 03-15-2014, 04:12 AM

.

take a 5-10 mile ride,park and take the valve cover cap off (gently) while idle
if you have serious blow by the cap will fly

video here

.

mach4 · #44 03-15-2014, 10:46 AM

Quote:

Originally Posted by iceman104

Interested in possibly buying one of these off you. My 85 300sd has a separator and drain hole in oil pan. But some how the oil isnt making its way in the passage way made for it. It end up all in my air filter then draining out a small hole in bottom of oil box and all over the car in enge bay. Is this because a bad separator or do i have ALOT of blow by? What can i do please help.

Mine is a custom designed catch can with the shape and brackets specifically designed for my 380SL diesel conversion project. Wouldn't work for your setup. You'd be better off getting a general purpose one off eBay - just search "catch can".

Check your drain valve. Maybe it's clogged and won't allow the oil to drain back into the air filter. If it is you can replace it, or get a catch can style that you manually drain periodically.

gregp1962 · #45 08-10-2021, 01:07 PM

Mach4, How is this setup working for you now that years have passed? Do you still have the converted SL?