Motorsport Air Oil Separator 986 fitting

[The Radium King]

Originally Posted by steved0x

I've always wondered - if the difference between the two is just the size of the oil reservoir, could somebody mod the original AOS so that is can hold more volume, maybe by adding a piggyback container that joined to the side so that the AOS would not overfill with oil and give it a little more time to exit in the proper way. I wonder if there is even room. Or the hose that takes the oil from the AOS and returns it to the engine - could it be replaced with a longer hose, thereby providing a little extra capacity, maybe just enough to keep the oil from overfilling the AOS.

Just random thoughts.



Yeah, I have blown the smoke bomb once at the track, in my case I had accidentally filled the oil 1-2 bars over the full line just as you describe. The power cut out of the car (similar to when the TC comes on or when you hit the rev limiter), flashing CEL for a few seconds, reading the code later it was misfires on a couple of cylinders. It was scary.

what you can do is take the pipe that runs from your aos to your intake and route it through an afternarket air/oil seperator OR an oil catchcan then back to your intake. this way, if your primary aos fails, you have some pre-warning that something is afoot and can take action before hydrolock, smoke bombs, etc. the other thing to note is that the aos has several iterations as porsche improved the design; make sure you have the latest (latest version is .04, although there is as version for the +03 models that may fit as well ...).

[BYprodriver]

Originally Posted by The Radium King

what you can do is take the pipe that runs from your aos to your intake and route it through an afternarket air/oil seperator OR an oil catchcan then back to your intake. this way, if your primary aos fails, you have some pre-warning that something is afoot and can take action before hydrolock, smoke bombs, etc. the other thing to note is that the aos has several iterations as porsche improved the design; make sure you have the latest (latest version is .04, although there is as version for the +03 models that may fit as well ...).

'03> version connections are very different from original configuration as seen in OP pic.

I don't know if he will be able make it work on his race engine much less a stock 96-02

[jml911]

Well the good news is that the motorsport / race oil separator valve part no: 996 107 926 00 will fit a 986 3.2 engine just fine.

Difficult to show you exactly how we got it to work but it did need a few new pipes and connectors to be made up but it wasn't a big job.

Best bit - it's cured the oil ingestion problem and no more smoke blowing out in left hand corners.

[Paseb]

do you need parts/hoses from porsche to install the new AOS?

i had another big cloud of smoke during my race this weekend. I think my oïl level was a little over but still, i want to install one...

Originally Posted by jml911

Well the good news is that the motorsport / race oil separator valve part no: 996 107 926 00 will fit a 986 3.2 engine just fine.

Difficult to show you exactly how we got it to work but it did need a few new pipes and connectors to be made up but it wasn't a big job.

Best bit - it's cured the oil ingestion problem and no more smoke blowing out in left hand corners.

[Gelbster]

Pelican has the correct part number- the latest that Radium kindly mentions:
996-107-023-04. They offer a choice of OEM or the much cheaper URO brand.Anybody care to comment on the URO ? It is 1/2 price!
Has anyone got a specific recommendation for a catch can to use and experience of how well it works ? I have used them on other vehicles and found them excellent if you position them intelligently.
There is not much room but wondered if anyone had tried this?Has 12AN fittings.
Pro Series Baffled Oil Catch Can Honda Civic Acura Integra 6 Port Black 12 An | eBay

Originally Posted by The Radium King

what you can do is take the pipe that runs from your aos to your intake and route it through an afternarket air/oil seperator OR an oil catchcan then back to your intake. this way, if your primary aos fails, you have some pre-warning that something is afoot and can take action before hydrolock, smoke bombs, etc. the other thing to note is that the aos has several iterations as porsche improved the design; make sure you have the latest (latest version is .04, although there is as version for the +03 models that may fit as well ...).

[kiyakubuke]

I was talking to a guy with a cayman s at the track a few weeks ago. his solution was to remove the upper vent line and plug the hole at the throttle and the one on the top of the AOS. He said that the AOS was basically just a emissions thing and did not effect performance etc.. so by blocking it off it prevented any oil from getting into the intake and had no negative side effects other than increased tailpipe emissions.
From what I understand about how the AOS works, I think his logic is sound, just not sure I would take the chance on mine without knowing for 100% that it would not harm the engine.

[Gelbster]

Kiyak,
Interesting story,thanks for sharing.
Logically, you could just put a partial restrictor in that line. That would reduce the quantity of oil that could pass. It would allow fumes to pass as normal. The tree-huggers may prefer that?

[kiyakubuke]

Originally Posted by Gelbster

Kiyak,
Interesting story,thanks for sharing.
Logically, you could just put a partial restrictor in that line. That would reduce the quantity of oil that could pass. It would allow fumes to pass as normal. The tree-huggers may prefer that?

If I was going to do it I would put a shut-off in line of the upper vent line. that way I could just shut it off at the track, and back on for normal driving. beats $800 for the track AOS.

[mikefocke]

Isn't the AOS also there to release crankcase pressure by allowing the venting of mist and separating out its components? Without the AOS to allow the venting, where else would the pressure go?

[Steve Tinker]

Originally Posted by mikefocke

Isn't the AOS also there to release crankcase pressure by allowing the venting of mist and separating out its components? Without the AOS to allow the venting, where else would the pressure go?

Probably through the crankshaft oil seals (whistling sound) or up past the piston rings.
Remember the M96 engines have a relatively light piston ring pressure compared to older engines - it wouldn't take much positive crankcase pressure to force them back with not very nice consequences.....

[BYprodriver]

Originally Posted by Gelbster

Kiyak,
Interesting story,thanks for sharing.
Logically, you could just put a partial restrictor in that line. That would reduce the quantity of oil that could pass. It would allow fumes to pass as normal. The tree-huggers may prefer that?

I'm afraid that would cause a stronger vacuum signal, one of these days I'm going to try & increase the diameter of the connecting hose.

[kiyakubuke]

I think I agree with you guys. might work, but I would prefer not to take the chance.

[renn68]

jml - what fittings did you use for A-A and B-B? Even a sketch of what you did would be helpful

G :-)