MyE28.com

I was up at KB Motorsports today and Jesse ( the mechanic that has been helping with my turbo project) brought in his E28 and gave me a ride..................

All I can say is !!!!

Here is what I know about the car:

US spec 1988 E28 M5 with a Euro M88 motor and DINAN turbo, custom exhaust, MSD ignition and some other tweaks (still a work in progress as Jesse says).

HP is well into the 500hp range (the boost gauge he had hooked up was pegged at 15psi). I have to say its probably the quickest automobile I have ever been in and makes unbelievable noises
Here are some pictures:

What is an M88 doining in a US spec E28?

Duke M535ti wrote:What is an M88 doining in a US spec E28?

Apparently kicking ass.

rediculous setup, wish I had somethin like that

why is the valve cover breather hose open to the atmopshere? I never really understood why there was the breather pipe between the valve cover and the intake plenum, but in this engine the VC is open. I can understand why you wouldn't connect it to the plenum - that thing is now pressurized, but in an NA engine, what function is there for this hose? and why is it ok to run open in a turbo?

where is the air filter / cleaner assembly? i see an aftercooler where the factory airbox is - where is the air intake now?

I am impressed that the A/C was retained in this car, and the A/C / fuel cooler exchanger was retained as well. Many BMW turbos seem to lose the A/C system.

oh, also - there is no vacuum/manifold refernce on the FPR. On boosted engines is this the norm? Or is something else happening here to make the fuel pressure appropriate based on vacuum/boost? Or is this compensated for in the map with longer / shorter injector open times? what engine management is this car running?

Can someone explain this overflow business to me?

<img src="http://www.solisearch.net/ims/pic.php?u ... j&i=292800">

The PCV is not necassary unless you need to pass smog. On Dinan turbo systems, the valve cover air tube is normally plumb'd just after the AFM where there is always a very small amount of vacum. That way its never pressurized. That gent for whatever reason decided to remove that piece of plumbing.

On the intkake, its under the car with probably a cold air intake in the front spoiler. He also may have a aftermarket ECU that doesn't use the AFM. Maybe a MAF conversion or some other air measuring device. We don't know.

The FPR can be capped off if the ECU is tuned for it. Plus, in the last pic, there is a FMU that can control fuel pressure uner boost. With the stock FPR capped, you always get max pressure from it. You just have to tune the ECU for. All Dinan turbo systems are customed tuned by SteveD himself. So capping the FPR is OK.

RussC

Matt wrote:why is the valve cover breather hose open to the atmopshere? I never really understood why there was the breather pipe between the valve cover and the intake plenum, but in this engine the VC is open. I can understand why you wouldn't connect it to the plenum - that thing is now pressurized, but in an NA engine, what function is there for this hose? and why is it ok to run open in a turbo?

where is the air filter / cleaner assembly? i see an aftercooler where the factory airbox is - where is the air intake now?

I am impressed that the A/C was retained in this car, and the A/C / fuel cooler exchanger was retained as well. Many BMW turbos seem to lose the A/C system.

Car is running a standalone so the pipe between the valve cover and VC can be open.

Intake is likely in the front valance area prior to the turbo inlet.

All TCD systems are designed to retain the a/c systems.

Todd

Matt wrote:why is the valve cover breather hose open to the atmopshere? I never really understood why there was the breather pipe between the valve cover and the intake plenum, but in this engine the VC is open. I can understand why you wouldn't connect it to the plenum - that thing is now pressurized, but in an NA engine, what function is there for this hose? and why is it ok to run open in a turbo?

where is the air filter / cleaner assembly? i see an aftercooler where the factory airbox is - where is the air intake now?

I am impressed that the A/C was retained in this car, and the A/C / fuel cooler exchanger was retained as well. Many BMW turbos seem to lose the A/C system.

The breather, when piped into the intake tract creates vacuum in the block... this promotes better piston ring to cylinder sealing. He would be better off having this connected. You can leave it open on any engine as long as the port to the intake is plugged. Otherwise, you have a huge air leak.
This car is using a RRFPR. Why the signal line to the stock FPR is disconnected I don't know. Perhaps the stock FPR is modified to remain open or it is just supplying it's maximum pressure all the time.

Booker, that overflow system looks stock. This setup is required on the M88/S38 to properly bleed the t-stat housing and head. On the M30 (as you know) there is a bleed screw at the highest point in the system... not so on these puppies.

Ahhh.... Thanks.

The car runs a MS v3.0 I understand.

Jessie..the owner is n aquaintence of mine.he epitomizes the new breed of tech, that is not satisfied with plugging in a computer and reading fault codes.
Jessies big kick is trouble shooting the old way.one wire, one system at a time.
to that end he's building his own stand alone mega squirt engine management system. it will ultimately replace the current set-up.
as for the m88,......he bought the motor with the dinan components and has replaced his us spec s38 with the aforementioned.
( the s38 is has been transplanted into an early 3.0 coupe )
great kid, lotsa enthusiasm and a willingness to build on his own and learn from his errors.
if youre in n.san diego county.....he's a helluva tech to have on your side...........


by the way.........it passed californias smog requirements.......

If the car is smogged, there is only two ways to get that car smogged in CA.

First, cheat. Dinan never EO certified the E28 S38 turbo kit. So it will never pass a visual inspection. But, you can get techs to pass it through whatever means you can think of.

Second, get your own cert through the ARB referee. That cost a good deal of money. I doubt he did that

Tuning it to pass CA smog is very simple if he did all the MS stuff himself. It just needs to run closed loop off boost with a minimal cat converter. It will run as clean as a stock E28.

RussC

Matt wrote:why is the valve cover breather hose open to the atmopshere? I never really understood why there was the breather pipe between the valve cover and the intake plenum, but in this engine the VC is open. I can understand why you wouldn't connect it to the plenum - that thing is now pressurized, but in an NA engine, what function is there for this hose? and why is it ok to run open in a turbo?

where is the air filter / cleaner assembly? i see an aftercooler where the factory airbox is - where is the air intake now?

I am impressed that the A/C was retained in this car, and the A/C / fuel cooler exchanger was retained as well. Many BMW turbos seem to lose the A/C system.

Matt, in this picture it can be seen how Dinan plumbed the crankcase ventilation between the turbo low presure/AFM side and the valve cover.

Interesting!

Isn't that vent hose a source of oil buildup in the intake system? I assume this is upstream of the turbo and the aftercooler. What happens to an aftercooler with oil film on the inside of it? I would imagine it is undesirable?

An inline oil separator would seem prudent here?

Matt wrote:Interesting!
Isn't that vent hose a source of oil buildup in the intake system?

Yes

Matt wrote:I assume this is upstream of the turbo and the aftercooler.

You are correct.

Matt wrote:What happens to an aftercooler with oil film on the inside of it?

Efficiency is reduced

Matt wrote:I would imagine it is undesirable?

It's an engineering tradeoff. If crankcase pressure isn't vented, external seals (valve cover gasket, f&r main seals, and oil pan) will leak. Venting to the atmosphere is unlawful on an E28. That leaves venting to the intake circuit. It's a solution but as you've said, it contaminates the intake tract. It results in oil dilution of the intake charge reducing power and increasing residual by products of combustion. In addition, it reduces internal engine cooling and can increase detonation as a function of unspent byproducts of combustion. On the positive side the additional oil in the charge mixture may reduce upper cylinder and valve guide wear by increasing lubrication.

Matt wrote:An inline oil separator would seem prudent here?

There is an "inline oil seperator" of sorts in the valve cover. There is an oil baffle where oil is separated from air and drains back into the crankcase; it's what BMW used.

M635CSi wrote: There is an "inline oil seperator" of sorts in the valve cover. There is an oil baffle where oil is separated from air and drains back into the crankcase; it's what BMW used.

It's not a separator, rather, a simple baffle to keep oil splash from entering the vent system... oil vapor flows freely past it.

I made a separator for the vent system on my twin turbo and located it on the driver's side. This creates a long path and cooler location to help condense and collect the vapor. It will collect about 1/2 pint of oil per month (tired engine). On my new engine the drain line will be plumbed back to the sump so it's maintenance free. The M88/S38 intake plenum has a small hose attached to the oil dip stick tube to drain oil that has accumulated.
It is recommended that intercoolers and associated intake plumbing be cleaned periodically. If I recall, Buick recommended a yearly drain and clean of the GN's intercooler.

Sweeney wrote:

M635CSi wrote: There is an "inline oil seperator" of sorts in the valve cover. There is an oil baffle where oil is separated from air and drains back into the crankcase; it's what BMW used.

It's not a separator, rather, a simple baffle to keep oil splash from entering the vent system... oil vapor flows freely past it.

It seems you're drawing a distinction without difference. The BMW baffle is an oil separator "of sorts." It was designed to seperator oil with an internal baffle and does serve as an oil separator with one surface finned for cooling and exposed to lower temperatures It is an oil separator to” separate” the oil splash from entering the vent system.

M635CSi wrote:

Sweeney wrote:

M635CSi wrote: There is an "inline oil seperator" of sorts in the valve cover. There is an oil baffle where oil is separated from air and drains back into the crankcase; it's what BMW used.

It's not a separator, rather, a simple baffle to keep oil splash from entering the vent system... oil vapor flows freely past it.

It seems you're drawing a distinction without difference. The BMW baffle being an oil separator "of sorts." It was designed as an oil seperator with an internal baffle and does serve as an oil separator with one surface finned for cooling and exposed to lower temperature thereby serving to seperate the oil from vapor. It is in fact an oil separator to” separate” the oil splash from entering the vent system...

I believe Matt was referring to a devise dedicated to filtering oil vapor from the atmosphere... the structure in the BMW valve cover is no such devise though a small amount of the oil vapor may condense (though the temperature differential between the vapor and internal metal surfaces is, I assume, close to nil, but, perhaps higher temps exist in the baffle area as all heated atmosphere from the crank case is routed through this area).
There are also no dedicated "cooling fins" in this area on either the M88/S38 or M30 valve covers. There are baffles that effectively increase the path length to allow oil splash to "drop out" before becoming entrained in the vent flow. The M88 has 7 such baffles and the M30 has 3. These are not designed to collect/remove vapor as a separator would.

Sweeney wrote:

M635CSi wrote: There is an "inline oil separator" of sorts in the valve cover. There is an oil baffle where oil is separated from air and drains back into the crankcase; it's what BMW used.

Sweeney wrote:It's not a separator, rather, a simple baffle to keep oil splash from entering the vent system... oil vapor flows freely past it.

It seems you're drawing a distinction without difference. The BMW baffle being an oil separator "of sorts." It was designed as an oil separator with an internal baffle and does serve as an oil separator with one surface finned for cooling and exposed to lower temperature thereby serving to separate the oil from vapor. It is in fact an oil separator to” separate” the oil splash from entering the vent system...

Sweeney wrote:I believe Matt was referring to a devise dedicated to filtering oil vapor from the atmosphere... the structure in the BMW valve cover is no such devise

I agree, but since there is no need for a "devise dedicated to filtering oil vapor from the atmosphere" I said “of sorts" because the BMW unit is all that is on the engine for oil separation. The design of the BMW unit is more along the lines of oil separators sold for use in lightweight piston aircraft engines made with simple baffles.

Sweeney wrote:though a small amount of the oil vapor may condense (though the temperature differential between the vapor and internal metal surfaces is, I assume, close to nil, but, perhaps higher temps exist in the baffle area as all heated atmosphere from the crank case is routed through this area).
There are also no dedicated "cooling fins" in this area on either the M88/S38 or M30 valve covers.

The BMW design benefits from cooling fins on the valve cover which are exposed to a significant temperature differential but which is somewhat irrelevant because the baffles do the job

Sweeney wrote:There are baffles that effectively increase the path length to allow oil splash to "drop out" before becoming entrained in the vent flow. The M88 has 7 such baffles and the M30 has 3. These are not designed to collect/remove vapor as a separator would.

You’re defining your terms to meet your objectives. Oil separators are in use every day that are designed with a few baffles to separate the oil - these are commonly known as oil separators. There is no need for a "devise dedicated to filtering oil vapor from the atmosphere". If the internal seals (rings and valve guides) need replacing then the heat of combustion leaking past the seals will indeed cause oil to vaporize. The solution to that problem is to repair the seals on the engine. The solution I'm working on for the M635CSi/M88 turbo is to use a scavenge pump.

Defining terms to meet my objectives? I don't think so.

You're describing cosmetic, raised lines on the valve cover as "cooling fins". In fact, the "M POWER" logo on the M88 covers 90% of the area of the baffles. The cross sectional area of the passage through the baffles is equal to or slightly greater than the port into the vent tube with very few baffles... 3 and 4 baffles for either inlet on the "M" valve cover. There is also very little surface area for vapor to condense.
Actual vapor separators have a relatively large volume compared to the inlet and outlet and contain condensing plates/media with lots of surface area. The large volume provides a relatively low energy environment that allows for separation and collection.
The structures in the valve cover do not compare to a true separator.
The BMW design, as with most other manufacturer's, is an attempt to keep liquid oil from entering the vent system while the vent system transports oil vapor, combustion gases, etc back to the intake system to be burned.
If these BMW valve covers have what are intended to be oil vapor separators then the designer needs to go back to school.
You are correct that there isn't a need for a dedicated devise. There is a benefit to one though.

I don't want to get in the argument, but i've had the valve cover off a BMW engine enough times to nkow about the splash baffle. Inspite of that, i get grime/sludge buid up in my breather hose, so i an only surmise that vaporized oil (or some amount of liquid oil) still makes it past the basic baffle, and if i think about that grime coating on the inside of an aftercooler, it doesn't make me feel spectacular

So yeah, i was talking more about something that would clean any oil residues/vapors/anything that can turn into a grimy inside coating on the aftercooler. The factory baffle is not even up to the task of keeping my breather hose clean, so thus my questions about it getting into the aftercooler and clogging that thing up

Sweeney wrote:Defining terms to meet my objectives? I don't think so.

I said you're defining terms to meet your objectives because you keep using the term "oil vapor separator" interchangeably with oil separator. The baffle in the BMW valve cover is clearly intended, as you agreed, to separate oil and keep it from going back to the intake. The fact that it is a very simple baffle type oil separator is not the issue.

Sweeney wrote:You're describing cosmetic, raised lines on the valve cover as "cooling fins". In fact, the "M POWER" logo on the M88 covers 90% of the area of the baffles.

Yes, you are correct. The cooling fins on the M88/S38 and M30 valve cover are mostly cosmetic and provice minimal cooling.

Sweeney wrote:The cross sectional area of the passage through the baffles is equal to or slightly greater than the port into the vent tube with very few baffles... 3 and 4 baffles for either inlet on the "M" valve cover. There is also very little surface area for vapor to condense.

I suspect that is because BMW saw a need for an oil separator and not a vapor condenser...

Sweeney wrote:Actual vapor separators have a relatively large volume compared to the inlet and outlet and contain condensing plates/media with lots of surface area. The large volume provides a relatively low energy environment that allows for separation and collection.

BMW used an oil separator of sorts not a vapor separator

Sweeney wrote:The structures in the valve cover do not compare to a true separator.

Oh they compare, they just compare unfavorably. That is why I described it as an oil separator “of sorts”

Sweeney wrote:The BMW design, as with most other manufacturer's, is an attempt to keep liquid oil from entering the vent system

Yes, separate the oil... as in what an oil separator does.

Sweeney wrote:while the vent system transports oil vapor, combustion gases, etc back to the intake system to be burned. If these BMW valve covers have what are intended to be oil vapor separators then the designer needs to go back to school.

Repeating the term "oil vapor separator" does not make it relevant. The oil separator in the BMW valve cover is not intended as a vapor condenser but rather as an oil separator. BMW engineers do not need to go back to school. But the BMW accountants may need a good talking to. I'm sure they had something to say about how much the valve cover and PCV system on the M88/S38 engine should cost.

Sweeney wrote:You are correct that there isn't a need for a dedicated devise. There is a benefit to one though.

I see the problem with the BMW crankcase ventilation system as fundamental to the lubrication system BMW chose which is made worse by putting the engine under boost.

Matt wrote:I don't want to get in the argument, but i've had the valve cover off a BMW engine enough times to nkow about the splash baffle. Inspite of that, i get grime/sludge buid up in my breather hose, so i an only surmise that vaporized oil (or some amount of liquid oil) still makes it past the basic baffle, and if i think about that grime coating on the inside of an aftercooler, it doesn't make me feel spectacular

That's a good point. I don't think the grime/sludge build up in the breather hose is caused by oil vapor but by contaminants carried in the oil mist from the bellows effect of the crankcase.

Matt wrote:So yeah, i was talking more about something that would clean any oil residues/vapors/anything that can turn into a grimy inside coating on the aftercooler. The factory baffle is not even up to the task of keeping my breather hose clean, so thus my questions about it getting into the aftercooler and clogging that thing up

If you find anything but clean oil, the engine probably has one or more bad seals.

"Oil vapor separator" is relevant because that's what this whole discussion has been about... preventing oil vapor from reaching and collecting on components in the intake tract.
In the context of discussion "oil vapor" and "oil" are interchangeable... oil vapor is, in fact, oil... in the form of vapor.

Can you explain the "bellows effect" of the crank case, please?

Sweeney wrote:"Oil vapor separator" is relevant because that's what this whole discussion has been about... preventing oil vapor from reaching and collecting on components in the intake tract.

I don't agree that oil vapor separation is "relevant." It's not what I said BMW had in the valve cover and it's not really what this discussion is about. And to that extent, it is inappropriate to use the term interchangeably with the term I used. I never said there was an oil vapor separator in the valve cover and I don’t agree that an oil separator and an oil vapor separator are the same.

Sweeney wrote:In the context of discussion "oil vapor" and "oil" are interchangeable... oil vapor is, in fact, oil... in the form of vapor.

Oh no, it is not the same in the context of this discussion. In a healthy running engine, oil exists primarily as a liquid and as a fine mist or as small droplets. Very little oil is in the form of actual oil vapor, although it seems a convenient term to use. The reason I bring this up is because different techniques must be used to separate a fine mist or small droplets of oil from the atmosphere than are used to separate an actual oil vapor from the atmosphere. Oil separators (to separate oil mist) can be made with metal baffles. An actual oil vapor separator can not use metal baffles to effectivly separate the oil vapor. The oil in suspension in the crankcase is not primarily oil vapor. It is oil mist or small droplets of oil that fall out of suspension onto the inner hose linings and other internal components. To the extent internal engine seals leak, there will be more oil vapor as the result of hot gases blowing past the internal seals into the crankcase and valve cover and vaporizing the oil. I do not believe this vapor is what settles on the inside of the plenum or hoses but rather, the oil mist that precipitates pollutants out of the hot exhaust gases and subsequently settle on surfaces as residue and dirty oil. The actual oil vapor does not settle on the inside of the engine components.

Sweeney wrote:Can you explain the "bellows effect" of the crank case, please?

I'm not sure it's such a good term to use but I meant to convey the effect the pumping action of the pistons have on the crankcase/valve cover vents, a pressure pulse is evident when the vent is open to the atmosphere.

Sweeney wrote:

M635CSi wrote:
I made a separator for the vent system on my twin turbo and located it on the driver's side. This creates a long path and cooler location to help condense and collect the vapor. It will collect about 1/2 pint of oil per month (tired engine). On my new engine the drain line will be plumbed back to the sump so it's maintenance free. .

Mmm. Food for thought.

There was a recent thread on anothor forum where they were talking about using the exhaust for vacuum and plumbing the vent into there (using a check/arrestor valve). I have no idea how that might affect the cat(s).