Air Intake Mod.... - PeachParts Mercedes-Benz Forum

DieselHead · #1 04-28-2003, 04:29 PM

Hi,
After getting some inspiration from a thread started a short while ago about boost controllers and K&N filters, I decided to do what dieseldiehard did and buy a K&N to bolt directly to the turbo. The pics should pretty much say it all, but if there are any questions, please ask.

The oil separator is made from PVC pipe and matching end caps, brass hose fittings, rubber automotive tubing, and two copper scrubbing pads on the inside. Air that is fed back into the intake comes out of the top of the device, the air/oil mix from the crankcase goes in through the side, and the oil comes out the bottom back into the oil pan.

This thing is kind of a first run. I plan on redoing the home made oil separator using wider but stubbier PVC. The car runs great though, and the turbo sound is much more pronounced. Around town, it's only a little faster, but on the highway it's a completely new car. I carry the original air filter unit in my trunk with the necessary tools needed to reinstall it, just in case something happens. I've driving 50 miles though, and everything seems A-Okay, except for a little leakage from the separator. I'll address that with some silicone sealant.

Alex

DieselHead · #2 04-28-2003, 04:29 PM

the air filter....

DieselHead · #3 04-28-2003, 04:30 PM

the separator...

sixto · #4 04-28-2003, 04:42 PM

How do you relieve crank case pressure? One benefit of routing the valve cover hose to the air cleaner is that there is lower pressure in the air cleaner than in the crank case so air flows. If you route the valve cover hose back into the crank case, you hardly need the catch can as (a) there is no pressure difference to induce air flow and (b) you're not keeping oil from going anywhere you don't want it to go.

Or am I missing something?

Sixto
91 300SE
87 300SDL
83 300SD

DieselHead · #5 04-28-2003, 04:49 PM

The oil separator, the white pipe, separates the oil from the air the crackcase gas that comes out of the valve cover. The air is burned (you'll see that a rubber tube goes in to the air filter) and the oil is returned to the oil pan, just like how the original oil/air separator worked.

Alex

sixto · #6 04-28-2003, 05:00 PM

Gotcha. I didn't notice that it had 3 fittings.

Sixto
91 300SE
87 300SDL
83 300SD

BIGRED · #7 04-28-2003, 05:16 PM

Nice effort. Down the road I plan to modify the air intake. I wanted to try and go with some type of FIPK to draw cold air in from either below or ontop. Your hookup has given me a few ideas.

#8 04-28-2003, 05:24 PM

Looks killer and may very well increase performance. My only concern would possibly be operation in very wet weather. What's your take on that matter?

rwthomas1 · #9 04-28-2003, 07:28 PM

How about before and after 0-60 runs? Nice job. Keep the K&N well-oiled, they don't filter worth a squat when dry.... RT

DieselHead · #10 04-28-2003, 07:44 PM

Thanks. Unfortunetely, I never really timed the 0-60 before. I figure that with a car like this, it doesn't really matter as long as it's fast enough to be safe. I have to go by the seat of the pants method, but I'm absolutely sure that the highway performance is better. I'm going to keep it as is for another 100 miles and assess whether or not it's breathing well. If I get lazy and decide to keep the oil separator the way it is, I'll paint it red or something so it's not so ugly. I can't decide whether or not it's better the way it is now, or if it would be better to have the oil from the oil separator drain out into a container instead of having it recycled back into the system.

Regarding wet performance, we shall see. I'll see how wet it gets the next time it rains and if it's really bad, I'll buy a filter cover that K&N sells.

Alex

ned2683 · #11 04-28-2003, 08:46 PM

you should make a cut away picture on how you made the oil separator.

BIGRED · #12 04-28-2003, 09:16 PM

Quote:

Originally posted by TheVirginiaDude
Ever give thought to making this thing using all copper and brass? You can get the larger coppr pipe at a plumbing supply place and the brass fittings are easy. Will look professional will not be effcted by the enine heat like PVC will be.

I was thinking the same thing and then with a bit of brazing mount it to the air cleaner bracket. With a bitt of buffing you can make it shine as well!

DieselHead · #13 04-28-2003, 09:38 PM

Ned,
Unfortunetely, I'm not very handy with photoshop so I wouldn't know how to draw up a schematic of what I did. I will try to explain the process a little later tonight when I have a tad more time, or I'll draw up something really crude.

VirginiaDude and BIGRED,
Copper was what I was thinking too when I was at Home Depot looking for all the materials. I chose the PVC though because I figured this was just going to be a trial run. I made some mistakes with this first try which I'll have to correct the next go around. I'm going to do one more with PVC and then do a third and final edition with copper. What would I use for end caps if I used copper? Also, with the final version, I'll find a way to mount it more securely and permanently.

Alex

ned2683 · #14 04-28-2003, 09:42 PM

thanks, i am not so sure how the oil separator works. and so i don't know where all the hoses are suppose to connect. i was gonna make one using cheap $20 ricer cone air filter at first and eventualy when i have money i'll get a K&N. what size opening is that?

and if you use copper piping i suppose you can get end caps and drill and tap each ends. good work you got there, keep us up to date.

DieselHead · #15 04-28-2003, 10:01 PM

Here's the thing with that K&N. I bought that particular one (stock number RU1000) because someone else bought it and is using it. The opening on the RU1000 is much bigger, or so it seems, than the end on the turbo where it attaches. It was initially really loose when I put it on, but as I tightened the hose clamp, it fit really nicely and is now very snug (after tightening the hose clamp, I shook it around a bit to make sure it wouldn't slide off). Make sure you clean the surface on the turbo so that there is no oily residue. I used brake parts cleaner on a rag.

According to the www.knfilters.com website, the inner diameter of the filter mounting flange is 2-7/16, but again, it seemed kind of large. Go here:
http://www.knfilters.com/universal/univrndstrt.htm

and take a look for yourself. Good luck. I bought my filter at www.driverfx.com for $35 or something like that. It's a pretty good online store (of course, I have no interest in them).

Alex