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There are several discussions in the forum for aftermarket Breather Systems for all 928s including the 1987 to 1992 engines. The one that stands out is the one from Precision Motorworks.
After several attempts to Info@precisionmtrwerks.com and one separate email to GregBBRD@aol.com asking for what the kit includes, if there are any options to choose from and price including shipping, still no reply.
First of all what do you think of the Precision Motorworks set up for an S4 and how do you do to buy it? 928 International seem to have it as well any opinions there?
Geo, another option is to make your own. With some hose, tee's and a baffled can, you can accomplish the same end results. Here is my setup (things quickly devolve into the typical Rennlist shenanigans, so only the first post is relevant):
I continue to have zero oil loss through the breather system. The only thing that the can has collected is water condensate from driving in the winter. The primary aspect that I think makes the biggest difference is the large breather line connected to the oil filler cap.
Personally, I do not want water condensate collecting in an endless loop in the oil system, so allowing the catch can to drain into the oil sump was a non starter for me. If you never drive the car in cold weather, it might not ever become an issue for you. Otherwise, I encourage you to give serious consideration to whether or not you want to drain your oil catch can (Provent or other) back into your oil. I think that it's a very bad idea.
First question is do you actually have excessive oil usage? how many miles can you do before you need to add a quart?. GTS engines are often - though not always - heavy oil consumers (perhaps of the order of 1 quart every 500 miles - or more). Earlier S4 engines generally seems to be better with only occasional exceptions (or if tracked). If it isn't broken - I wouldn't fix it because it will likely not be cheap or easy.
I don't recommend by-passing a closed loop emissions system by venting to atmosphere under any conditions. Any water in the oil in the stock system is removed quite quickly once fully up to operating temperature via the intake - with a re-ingestion system (the only kind you should be considering IMO) water will not be a real concern.
I run a provent on my 89 vented from the passenger side valve cover breathers with great results. I do have it plumbed into the oil sump using a modified dipstick and a check valve.
The vent line is hooked up to the smog pump with the bypass valve's vacuum disconnected so it vents to the airbox at all times. Making it a mostly closed loop system. Well, enough so smog shops don't complain.
Before I installed the drain, the provent would collect at least 3 oz of oil after 30 miles of hard (in excess of 4k RPMs most of the time) driving. It would hardly separate anything under normal conditions like highway driving.
Now the thing leaks more oil than it consumes, which is fine with me.
on the Verus dual-chamber AOS I custom plumbed into my car. Prior, it was producing enough oil out the vent line to coat the windshield of a 928 buddy on a trip in as little as 5 miles, so much in fact that I ran the vent line to the back of the car so it wouldn't get all over the bottom of my car. After installing this, nothing but some pressure comes out the vent line - it as worked wonderfully. All the details are in my referenced thread.
There are several discussions in the forum for aftermarket Breather Systems for all 928s including the 1987 to 1992 engines. The one that stands out is the one from Precision Motorworks.
After several attempts to Info@precisionmtrwerks.com and one separate email to GregBBRD@aol.com asking for what the kit includes, if there are any options to choose from and price including shipping, still no reply.
First of all what do you think of the Precision Motorworks set up for an S4 and how do you do to buy it? 928 International seem to have it as well any opinions there?
Geo1965
My apologies, we've been absolutely swamped with orders and work and some things are slipping through the cracks.
In short, we're overwhelmed with things to do and our customer service for our custom pieces is what suffers first.
As an 'economy" more, we are not currently supplying a complete kit for the breather system, unless someone actually needs a complete system. (See next sentence.)
We found that a few select pieces out of our "complete system" reduces the amount of oil that can get to the intake manifold to such a tiny amount, that the "complete kit" isn't really necessary unless the engine is extremely worn out.
And instead of thousands of dollars for a complete kit (which you may not need) the "first step" pieces are ~$450 (with all gaskets and seals required)......and there is no overlapping labor, if you need to add in a complete ventilation kit, at a later date.
Additionally, there is no visual change to the engine bay, as there is with the complete ventilation kit.
While more conservative than our original complete kit, these "first step" pieces are definitely the way to go.
Ordering is simple.
Call Mary at 714 879 9072 and she will take care of your needs
Alternatively, you can Email her at MaryBBRD@att.net.
My apologies, we've been absolutely swamped with orders and work and some things are slipping through the cracks.
In short, we're overwhelmed with things to do and our customer service for our custom pieces is what suffers first.
As an 'economy" more, we are not currently supplying a complete kit for the breather system, unless someone actually needs a complete system. (See next sentence.)
We found that a few select pieces out of our "complete system" reduces the amount of oil that can get to the intake manifold to such a tiny amount, that the "complete kit" isn't really necessary unless the engine is extremely worn out.
And instead of thousands of dollars for a complete kit (which you may not need) the "first step" pieces are ~$450 (with all gaskets and seals required)......and there is no overlapping labor, if you need to add in a complete ventilation kit, at a later date.
Additionally, there is no visual change to the engine bay, as there is with the complete ventilation kit.
While more conservative than our original complete kit, these "first step" pieces are definitely the way to go.
Ordering is simple.
Call Mary at 714 879 9072 and she will take care of your needs
Alternatively, you can Email her at MaryBBRD@att.net.
Thank you, I will contact Mary.
Engine has new piston rings and seals so just trying to avoid too much oil fumes going into the intake in high RPM as I still see drops of oil on the rear bumper. Hope your stage 1 will eventually solve this.
Drops of oil on the rear bumper? do you mean soot deposits? Oil ingested will not survive a trip through the engine and still look like oil. We may be trying to solve the wrong problem here...
Engine has new piston rings and seals so just trying to avoid too much oil fumes going into the intake in high RPM as I still see drops of oil on the rear bumper. Hope your stage 1 will eventually solve this.
Regards,
Geo
My pieces are proven, time after time, to significantly reduce the amount of oil that collects in the intake system....otherwise there would be no point in making them, much less selling them.
However, I've seen many GTS engines which will use a quart of oil every 300-500 miles, which do not deposit oil on the bumper.
Are you sure you are not leaking oil from the engine, externally? (The airflow around a 928 chassis will carry oil from the front and wrap it around the rear, depositing it on the bumper.)
I emailed Mary and several months passed by but there is no reply from Mary or anybody else.Not sure what to conclude and if you are not selling these parts anymore, but in terms of customer service a response whatever this might be would have been better. If I am having so much trouble getting your parts I am thinking to go with the original parts or convert to a 928 GTS set up if marginally better.
I emailed Mary and several months passed by but there is no reply from Mary or anybody else.Not sure what to conclude and if you are not selling these parts anymore, but in terms of customer service a response whatever this might be would have been better. If I am having so much trouble getting your parts I am thinking to go with the original parts or convert to a 928 GTS set up if marginally better.
Regards,
George
Whatever you do, do not replace the S4 system with a GTS configured system- that is akin to taking epsom salts to cure diarrhea!
The stock S4 system is far from perfect but if everything is working as it should there appears to be a point of inflection around 4k rpms where oil consumption goes south thus why track junkies feel compelled to do something. I spent considerable time and effort trying to recover from my "GTS conversion debacle" including two inlet manifold off jobs over and above the original manifold off job to convert to the GTS configuration- my logic was driven by what turned out to be a dumb desire to make my by then installed 90 S4 motor look like a GTS!
If I were in the original S4 position today & looking to improve I would seriously consider the GB slimmed down option in the first instance as a path of least resistance. You can also take the DIY approach - quite a few such approaches are documented including mine that contains some DIY plumbing elements.
I concur with Fred - whatever you do - Don't covert to the GTS breather system. Porsche didn't seem to put much effort into this or do much verification of these breather changes - it was NOT a very effective system
I emailed Mary and several months passed by but there is no reply from Mary or anybody else.Not sure what to conclude and if you are not selling these parts anymore, but in terms of customer service a response whatever this might be would have been better. If I am having so much trouble getting your parts I am thinking to go with the original parts or convert to a 928 GTS set up if marginally better.
Regards,
George
Sorry.
I have no idea of what the problem is...Mary sometimes overlooks things or doesn't bring them to my attention, if there is a question.
Resend your "request" Email directly to my private email at GregBBRD@aol.com and I'll go staple it to Mary's computer screen.
Whatever you do, do not replace the S4 system with a GTS configured system- that is akin to taking epsom salts to cure diarrhea!
The stock S4 system is far from perfect but if everything is working as it should there appears to be a point of inflection around 4k rpms where oil consumption goes south thus why track junkies feel compelled to do something. I spent considerable time and effort trying to recover from my "GTS conversion debacle" including two inlet manifold off jobs over and above the original manifold off job to convert to the GTS configuration- my logic was driven by what turned out to be a dumb desire to make my by then installed 90 S4 motor look like a GTS!
If I were in the original S4 position today & looking to improve I would seriously consider the GB slimmed down option in the first instance as a path of least resistance. You can also take the DIY approach - quite a few such approaches are documented including mine that contains some DIY plumbing elements.
Nice! This is invaluable information, I will stick to my S4 set up then and see for eventual improvements.
05-26-2021, 06:41 AM
928 Breather System Upgrade
