crankcase venting

[Scottinva]

I will say everything I have heard from bmw master techs, and from my automotive school text books go into great deal of how great PCV valves are. They each mention the fact of how a PCV valve increases power output. I know of american drag cars that use vacuum pumps to pull EXTRA vacuum on the system, which increases performance further.

[Rich Euro M5]

I will say everything I have heard from bmw master techs, and from my automotive school text books go into great deal of how great PCV valves are. They each mention the fact of how a PCV valve increases power output. I know of american drag cars that use vacuum pumps to pull EXTRA vacuum on the system, which increases performance further.

Aviation engine don't have PCV systems, and these engines are all about creating maximum power efficiently. I don't buy into everything put in the text books, as some of this can be done to drive acceptance and certain societal changes. The PCV system by itself doesn't increase power, there was tuning required to compensate for the dilution, and other aspect as well, back when PCV systems were introduced 50 + years ago. .

If the power gains are there as you state, then provide a solution to your friends here utilizing this type of technology. However, will the cost benefit ratio support the gains you'll achieve in a worn M30 with a blower or turbo attached.

Rich

[Rich Euro M5]

Here is a possible solution for those that want to maintain a closed crankcase system. Someone with fabrication capabilities (George or Paul Burke) needs to build what's shown in the cutaway drawing below.



This device needs to be oriented as shown, the vent hose from the valve cover attaches to the angled large tube at the top of the separator, the large lower port connects to a hose, which then connects to the air intake tube between the air filter and the inlet of the turbo. The small output port on the bottom of the device is for the drain line. The S38B35 engine has a oil dipstick tube with a barb fitting, one could acquire this dipstick tube and the S38M5 oil dipstick for drain back. of the oil. Another solution is to add a barb fitting near the top of the oil pan.

Rich

[Rich Euro M5]

I will say everything I have heard from bmw master techs, and from my automotive school text books go into great deal of how great PCV valves are. They each mention the fact of how a PCV valve increases power output. I know of american drag cars that use vacuum pumps to pull EXTRA vacuum on the system, which increases performance further.

The highlighted text is a link to an excerpt from Today's Automotive Technician explaining why modern engines have PCV systems.

This article, specifically paragraph 6, details why some drag racers are using a vacuum pump to scavange the crankcase. It's more than simply bolting on a scavange pump, it's part of an engineered system utilizing low tension rings. I don't believe it's applicable to the typical M30 engine. If someone where to commission Paul Burke to build an engine with these types of rings, then it's valid.

Rich

[mooseheadm5]

Here is a possible solution for those that want to maintain a closed crankcase system. Someone with fabrication capabilities (George or Paul Burke) needs to build what's shown in the cutaway drawing below.



This device needs to be oriented as shown, the vent hose from the valve cover attaches to the angled large tube at the top of the separator, the large lower port connects to a hose, which then connects to the air intake tube between the air filter and the inlet of the turbo. The small output port on the bottom of the device is for the drain line. The S38B35 engine has a oil dipstick tube with a barb fitting, one could acquire this dipstick tube and the S38M5 oil dipstick for drain back. of the oil. Another solution is to add a barb fitting near the top of the oil pan.

Rich

The S38's barb fitting also has a really small oriface, just to add to the discussion.

I had been thinking about a catch can system like that, but I would add some special sauce internally (steel wool) to catch even more of the oil/water vapor.

PCV is also good for seals. It keeps oil from blowing past the front and rear crank seals when the. It also does reduce windage a little and reduces pumping losses at the expense of the charge dilution and intake fouling that Rich mentions. George's E-vac solution seems to be the best, and if there isn't a catch can system that works well enough on the market already, we'll design one.

[Shadow]

what are you guys arguing about?

It's dyno proven that good crank case vacuum makes more
power.

[Rich Euro M5]

what are you guys arguing about?

It's dyno proven that good crank case vacuum makes more
power.

I know why increasing vacuum on the crankcase improves power output, I want him to explain why.

Scottinva has studied automotive technology, therefore he should be able to provide the technical / engineering explanation for why this is so. To simply state some anecdotal crap about Master BMW Techs and his textbooks say so doesn't cut it.

For instance do you understand Paul's statement below, and know why it will catch more oil / water ?

I had been thinking about a catch can system like that, but I would add some special sauce internally (steel wool) to catch even more of the oil/water vapor.

There's a fairly easy explanation for why his special sauce will improve the functionality of the oil separator.

IMO, the guys that are doing FI builds should strive to understand what they are doing vs simply bolting parts together.

Rich

[Scottinva]

The drag guys were using pumps to help keep the oil in the system with the extra vacuum, the horsepower gains were just an added bonus. With added vacuum in the engine not only are you improving the ring seal, but if there is air pressure within the pistons stroke that is a resistance. By having vacuum you are taking this resistance away. I was having issues with oil getting into the breather tube. So I plan on running a catch can in place of the stock system, and hook it into the exhaust to get the engine vacuum I need, but not get all that oil into the intake. Under hard turns my engine gets ton of oil into the intake through that breather hose. I believe having vacuum on this system instead of just venting it to atmosphere, will have an added benefit to what I was trying to do with my car. "Bill in mn" was telling me about the steel wool inside of the catch can.

[Rich Euro M5]

The S38's barb fitting also has a really small oriface, just to add to the discussion.

I didn't look into the barb to see if there was an oriface in the barb. If it's too small then it becomes problematic for drainback due to plugging, but if the drain line is too large it would impact the functionality of the oil separator. I also have no idea how much draw the turbo inlet tube will have. I suppose one could measure the available vacuum using a water column. The sizing of the various pipes and hoses would need to be estimated, maybe even SWAG'd, then tested in application. Ideally a passive solution would be best for reliability, but if there isn't enough vacuum generated by the turbo inlet to reduce crankcase windage, then George's eVac solution would be a good method for generating the needed vacuum.

Rich

[winfred]

if mine decides it wants to pump oil through the evac system ill add a separator and plumb the drain back into the oilpan, just like a obdII bmw where the cyclonic valve drains into the dipstick tube, i am not running the oil level sensor and have a plate bolted over the hole, i can pull the plate and tap a hole in it and put in a fitting. it would be plenty easy to T into the dipstick tube and let the drain go there and pretty much never need to touch the system again unless sludge appeared and clogged something

[FirstFives Dictator]

I was having issues with oil getting into the breather tube. So I plan on running a catch can in place of the stock system, and hook it into the exhaust to get the engine vacuum I need, but not get all that oil into the intake. Under hard turns my engine gets ton of oil into the intake through that breather hose.

Like this?
http://www.youtube.com/watch?v=0p_F3snYdI4

[winfred]

wish our autocrosses were long enough to have oil distribution problems, depending on the coarse design fast cars get er dun low 40s upper 30s. i need to upload the vid of my shark, it was before i added a resonator and is even more obnoxious and raspy then yours

Like this?
http://www.youtube.com/watch?v=0p_F3snYdI4

[FirstFives Dictator]

wish our autocrosses were long enough to have oil distribution problems, depending on the coarse design fast cars get er dun low 40s upper 30s. i need to upload the vid of my shark, it was before i added a resonator and is even more obnoxious and raspy then yours

Like this?
http://www.youtube.com/watch?v=0p_F3snYdI4

I have a cat; does that count?
Really the reason most of these street-prepared exhausts sound like butt is we're trying to save weight.
If I wasn't so cheap, I'd spring for a Burns muffler.

[Rich Euro M5]

If I wasn't so cheap, I'd spring for a Burns muffler.

The Burns website is exhaust system porn. Really nice stuff, but the prices are

Rich

[Brad D.]

The Burns website is exhaust system porn. Really nice stuff, but the prices are

Rich

No kidding, Burns makes awesome stuff.

[winfred]

http://www.youtube.com/watch?v=O7vSLwYoxGw i may have ya on noise, it has a magnaflow crossover muffler for a resonator and lost most of the rasp and gained more burble, b35 manifolds and head pipes, kitty got lost and god knows what stainless catback, was told it was a stebro but not sure now


its about to get a set of stahl headers when i get the monster e30 roadworthy

Like this?
http://www.youtube.com/watch?v=0p_F3snYdI4

[mooseheadm5]

What rear muffler is that?

[winfred]

got it through kyle from todd and was told it was a stebro but if it is its a older design, the current ones the rear pipes come out over/under and the welds look like a high school shop class project, mine are side by side and the construction is great, mine has fatter pipes then the new ones too, any markings that were on it are gone, all stainless. it'll probably find its way onto my m635 as this shark has a turbo in its future, probably distant future with all of the shit i have to do

What rear muffler is that?

[George]

The Burns website is exhaust system porn. Really nice stuff, but the prices are

Rich

No kidding, Burns makes awesome stuff.

If you only knew how many times I've tried to order Burns stuff for work only be shot down by accounting. Bastards.

[Alfonso Bedoya]

I know this may seem frivolous to you guys, but I was thinking how about if a one way check valve was placed on the crank case vent with a K&N to promote healthy air post CFC's how'd that work? for vacuum? Plus the intake bellows hole from the crank case is plugged of course. Fuel purity..

Thanks in advance.

[FirstFives Dictator]

If you only knew how many times I've tried to order Burns stuff for work only be shot down by accounting. Bastards.

Don't they understand you're an artist trying to work...?