Oil Contaminant Separator (OCS) Orientation: The Official Word

[2LZ]

I'm not sure about motorcycle EFI's but back in the day when I was a wrench, car injections systems were only in open loop in "choke mode" and the ECM would function is set, mapped parameters. Once they heated up to operating temp, they switched to closed loop and stayed there allowing the O2 sensor and map/baro or MAF sensors to do their jobs and adjust air/fuel ration constantly through block learn and integrator in your ECM. If this is the case here, the O2 sensor would sniff the extra fuel being recycled and shorten the injector pulse width slightly to keep the air-fuel ratio as close to 14.7/1 as possible.
If this injection system works like that, I have no idea..........

[SpudRider]

Originally Posted by pyoungbl

Every motorcycle EFI system I'm familiar with (Ducati, Triumph, Moto Guzzi) runs in closed loop up to about 3500 rpm and then switches to open loop for higher rpms. Ours might have a higher crossover point but I'm pretty sure the closed loop is only significant for us at idle or just above idle. The EPA cycle could possibly dictate testing at some highway speed as opposed to a specific rpm range so that in itself would modify where the ECU goes from closed to open loop. On the other bikes it is common to have drivability issues at low throttle settings unless the ECU is re-mapped or the owner installs a gadget like a Power Commander to modify the fuel delivery. We do not seem to have that problem and I see no need to mess with the fuel map.

The amount of fuel being dumped by the OCS is really pretty small. I'd guess less than a cc in the batch that I dumped. There is much more water. Personally, I'm happy to see any water vapor being pulled from the crankcase. If it goes to the airbox or the ground...either is a good thing just as long as it is not in the oil. One could always install a larger catch bottle if the volume is a concern.

Thanks for your input, Peter. If you can provide links to any good articles regarding EFI systems, please do post them. We are always eager to learn more.

I agree with you completely; the OCS does a great job removing fuel and water contaminants from engine oil in the crankcase. Also, I'm sure most of the liquid content is water.

[detours]

Originally Posted by Juanro

And what if one connected the crankcase directly to the air box?
Wouldn't it be then that all contaminants would be burned? And then forget about draining or collecting...

I've wondered about that myself. My only concern would be that condensation inside the line would run back into the crankcase ... or get caught in a U-bend and block suction.

[SpudRider]

Originally Posted by Juanro

And what if one connected the crankcase directly to the air box?
Wouldn't it be then that all contaminants would be burned? And then forget about draining or collecting...

Many motorcycles do exactly as you stated. However, having an oil contaminant system is a superior design. The OCS traps contaminants as quickly as possible, and eliminates them from the crankcase. The single, long vertical hose employed by the other systems allows many contaminants to flow back into the crankcase before they ever reach the air box.

[SpudRider]

Originally Posted by 2LZ

I'm not sure about motorcycle EFI's but back in the day when I was a wrench, car injections systems were only in open loop in "choke mode" and the ECM would function is set, mapped parameters. Once they heated up to operating temp, they switched to closed loop and stayed there allowing the O2 sensor and map/baro or MAF sensors to do their jobs and adjust air/fuel ration constantly through block learn and integrator in your ECM. If this is the case here, the O2 sensor would sniff the extra fuel being recycled and shorten the injector pulse width slightly to keep the air-fuel ratio as close to 14.7/1 as possible.
If this injection system works like that, I have no idea..........

I think you know more than I about EFI systems, 2LZ. However, I am basing some of my speculations on the information I obtained from talking to the people at Dobeck Performance, when I was considering working with them to produce a EJK module for the RX3.

http://www.electronicjetkit.com/default.asp
http://www.dobeckperformance.com/

[SpudRider]

Originally Posted by detours

I've wondered about that myself. My only concern would be that condensation inside the line would run back into the crankcase ... or get caught in a U-bend and block suction.

Once again, you are correct, amigo. A lot of the water, and some of the fuel would drop back into the crankcase oil before it reached the air box. The OCS for the Zongshen RX3 is a very nice design.

[Juanro]

I guess if it comes out of the crankcase as vapor it could, in part, condensate over the pipe walls.. the OCS anyway is doing that on purpose.
Any fluid going back to the oil will evaporate again, in the next hot cycle.
Having a straight pipe is mandatory, anyway, any U bend will act as a reservoir and eventually fill up.
I'm not too fond of having to drain the OCS pipe, and in long trips it have filled up and made somewhat of a mess spilling oily fluid all over engine side. Nothing to worry about, my bike spends most of the time filthy anyway, haha

[keithmaine]

Originally Posted by detours

I've wondered about that myself. My only concern would be that condensation inside the line would run back into the crankcase ... or get caught in a U-bend and block suction.

you would not believe the crap in the air cleaner of my Ural that does just that, milky condensation mixed with an oily mess.

[dave92029]

Very interesting discussion, BUT for us non mechanics, would someone PLEASE post a picture of the best way to mount the OCS. Apparently there are merits to mounting the OCS both ways.

I "presume" that the preferred/ best method is the one that keeps "stuff" out of the crankcase and allows the engine to run smoothly at all rpm's.

Thanks for all your input.

[detours]

Originally Posted by dave92029

Very interesting discussion, BUT for us non mechanics, would someone PLEASE post a picture of the best way to mount the OCS. Apparently there are merits to mounting the OCS both ways.

I "presume" that the preferred/ best method is the one that keeps "stuff" out of the crankcase and allows the engine to run smoothly at all rpm's.

Thanks for all your input.

I'm not sure one way is more effective than the other at pulling vapor from the crankcase. Spud has run his 14,000 miles in the 'unofficial' orientation without ill effects. Myself and others have thousands of miles in the unofficial orientation.

To me, it's a question of whether you want more or less fluid in the catchtube:

• Official (cap toward top): More fuel vapor condenses in the catchtube. Less fuel vapor pulled into the air intake. Higher risk of filling up the OCS (and blocking suction) on long trips. Potentially better tailpipe emissions, but more fuel to pour on the ground.
• Unofficial (cap toward bottom): Less fuel vapor condenses in the catchtube. More fuel vapor pulled into the air intake. Lower risk of filling up the OCS (and blocking suction) on long trips. Potentially worse tailpipe emissions, but less fuel to pour on the ground.

For my part, unless CSC says the OCS orientation will affect my warranty ... or until I learn compelling reasons why burning fuel vapor from the OCS is worse on the environment than pouring fuel condensate on the ground ... I intend to mount my OCS 'upside-down', so as to burn as much of the fuel vapor from the crankcase as possible and to collect as little fuel in the catchtube as possible.

[willy dog]

i am leaning on the side of detours but then again not sure i want to burn the crap at the bottom of the tube might be draining it the way to go well getting very good at flipping it kind of like my opinion

[detours]

Originally Posted by willy dog

i am leaning on the side of detours but then again not sure i want to burn the crap at the bottom of the tube might be draining it the way to go well getting very good at flipping it kind of like my opinion

Oil and contaminants are actually at less risk of entering the airbox in the 'upside down' orientation.

Remember, the OCS filter is shaped like a cup.



In the 'upside down' orientation, vapors must pass through 2 filter walls (the side and the floor of the filter) before reaching the air intake. Heavy contaminants like oil and particulates will be filtered out by one or the other filter wall, dissolved in condensate fuel and dropped into the catchtube.



In the opposite 'official' orientation, vapor will only pass through one filter wall and up the open part of the cup. This is another reason why I like the 'upside down' orientation.

[SpudRider]

Originally Posted by detours

...For my part, unless CSC says the OCS orientation will affect my warranty ... or until I learn compelling reasons why burning fuel vapor from the OCS is worse on the environment than pouring fuel condensate on the ground ... I intend to mount my OCS 'upside-down', so as to burn as much of the fuel vapor from the crankcase as possible and to collect as little fuel in the catchtube as possible.

I agree. I was planning to flip my OCS as an experiment, but I noticed the hose from the crankcase cover to the OCS was kinked at an acute angle. Given the location of the mounting plate, the OCS is positioned at a much more natural orientation in the "unofficial" position. After riding over 14,000 miles without any problems, I don't see a good reason to change the position now. I much prefer to burn the captured fuel, rather than dump it. However, I don't think it will harm anything to mount the OCS either way.

[kumatae]

I just flipped mine around even though I've been riding trouble free for 8000 miles. I noticed that tube was filled with gas. I never had bother to drain it this whole time.

I agree with spudrider that the hose does seem kinked in acute angle but I went ahead and did the flip. Maybe later when I have more time, I'll shorten the tube to make it more natural. The process probably took all of 10 minutes at the max.

[rtking]

I flipped mine around to the "correct" orientation, but I don't like the kinked hose. I slept on it overnight and I'm pretty certain I'm going to change it back to the way it came (i.e. the "incorrect" orientation) as it never gave me a lick of trouble.