bbundy

Oil return line from the drain of the turbo is above the oil level in the sump. Oil return line from an oil seperator/vent to atmosphere catch can should be below the oil level in the sump.

Bob

bbundy

Oil return line from the turbo is above the oil level in the sump. Oil return line from an oil seperator/catch can should be below the oil level in the sump.

The Mazdaspeed turbo miata has an oil seperator system from the factory it returns the condensed oil below the oil level in the sump as well.

Bob

qes78

ok.
looks like i might have to seal off the vent on the lower block then.
losing too much oil
btw, would this have any connection whatsoever to me having knock now? previously I used to run knock free, but of late, been getting knock

qes78

i've decided to block off the vent on the lower block. now only connected the crankcase breather outlet from the valve cover to the oil catch tank.

Wondering if I should buy another oil catch for the PCV valve outlet.
hmmm

Doppelgänger

iTrader: (12)

Has anyone looked into the oil seperator system that BMW uses? It may be possible to impliment onto a Miata for a solution to all of this...

bbundy

I’m trying to work out a very similar system Vent crank case at valve cover and side of block. Have an effective separator with a return to the pan via an AN weld bung down low by the drain plug.

I have looked at some of the new heavy diesel technology. Motorized swirl pot separator with a filter element to separate oil return it to the pan and it pulls a vacuum on the crank case as well. Without a throttle body a PCV system just don’t work. Less than 10 years ago the state of the art for big diesel was a large tube from the valve cover pointed at the ground with the end cut at an angle so that air flow could create a slight vacuum. Condensate oil just dripped on the ground.

Bob

bbundy

My oil separator return line to the pan.

I welded the AN bung on first about the lowest spot on the pan I could find the fit good in the car. I put some water in it and decided it was not low enough to remain submerged with heavy sloshing going on so I added a tube on the inside of the pan to make it pickup all the way in the bottom. Since I welded the bung on first I couldn’t weld it seald so I had to resort to JB-weld to seal the additional tube.

This location should make it so the return line doesn’t spooge oil back up. With with gas pressure pulsations in the crank case.

Bob

Faeflora

iTrader: (2)

Would this work for a "block vent" ?

Put an air filter on the end of your dipstick tube.

I know this sounds ridiculous, but functionally, it would work, right?

JKav

iTrader: (1)

bbundy, re: returning the oil separator flow to a point below the sump's oil level -- is the thinking that crankcase pressure spikes are damped out by the oil in the sump?

bbundy

Correct.

In order for the pressure spike to get out from this port it would have to blow all the oil out of the sump first. Not likely to do that when there are 3 other vents above the sump oil level that will flow gas pressure pulses fairly easily.

Now if I can just figure out a really good separator system for the other 3 vents.

Bob

bbundy

No it wouldn’t work for a block vent. It is below the oil level in everything but left turns and hard braking.

It would work ok as gravity feed return from an oil separator like the BMW diagram shows I think.

It has shown to not work so good as a turbo oil return because that is pressure fed. Pressure fed wants to return above the sump oil level.

The dipstick also sometimes has issues as a dipstick on the miata especially if you don’t have good crank case ventilation because in some instances like hard left corners the dipstick hole in the pan is above the oil. A good gas pressure pulse when the dipstick hole in the pan is exposed to gas rather than oil will pop the dipstick out as it will try to act like a gas vent.

Bob

Faeflora

iTrader: (2)

OK, I figured it was below the oil line most of the time since it's the -oil dipstick- but I did not know why it blew out- during turns. Thanks for the explanation.

bbundy

I think numerous people who have flogged the crap out of there cars on the track have experienced the dip stick popping up and a bit of oil spray into the engine compartment by the dip stick. Seen it happen many times.

The owners usually freak out when it happens wondering what they screwed up then they put the dip stick back in and it doesn’t do it again. It is kind of an intermittent thing.

It can also happen very often on a boosted car with a bad PCV valve though and might happen more if you are low on oil.

Bob

qes78

i believe I've seen several Evo owners who have the same problem. In the end, they use something similar to the spring found on the hard top latches and tension the dipstick down

wildo

iTrader: (1)

Bob,

Have you looked at the Mann Hummel Provent 200?

I have one, it came highly recommended.
Got mine here:
http://www.efiexpress.com/catalog/pr...products_id=52

Won't be on the track with it for several months though. I have the drain plumbed to the oil pan via a one-way check valve (included with kit).

- Will

bbundy

That looks real interesting. seems wildly expensive for a plastic container with a filter in it though. What sizes are the inlet and outlets?

Bob

wildo

iTrader: (1)

The ports are huge. Inlet & outlet (or vent) are 1". Drain at the bottom is 1/2", and the in-line check valve is also 1/2".

I guess perception is everything! I actually thought it was cheap in comparison to most catch-cans (Moroso, Canton, etc). Full disclosure: EFI Express is local to me, and I've met the owner a few times. He is good friends with a friend of mine. That said, I only found out that they carried the Provent 200 after I did some research and decided to buy one.

I went to EFI's shop and saw a few installs. Seems these are very popular with turbo Audi/VW cars, especially the TDIs.

FWIW, other places I've found sell the Provent for a lot more $$$$. I was prepared to spend about $100 before I found the item on EFI's website.

Here's another source:
http://www.cfpfilters.com/store/provent200.html

Here are the tech specs of the Provent 200 and a few other models in that lineup:
http://www.mann-hummel.com/group/upl...BCHACUaaBi.pdf

Main Provent 200 page on Mann-Hummel's site:
http://www.mann-hummel.com/company/i...=35&rec_no=192

Mann-Hummel is an OEM provider of air & liquid filtration systems, and they seem to have a specialty in crank case ventilation systems. I wouldn't be surprised if they make the BMW system posted above ^^^^.

bbundy

Interesting the Mann-Hummel installation diagram shows the check valve on the return is only used for when the return is above the oil level. I think my return has that one covered. pretty much exaclty the type of system I was planning on installing. just hadnt worked out the details of the oil separator.

Bob

seraph

iTrader: (4)

I don't see alot of track time and am not getting any blow by on the driver port into the intake. I am getting a little bit through the pcv and was going to tap the pcv port 3/8npt to -10an and route to atm.

I was planning on doing the same to driver side but am not sure if I can tap 3/8npt on that side it looks kinda small. What size are you all using to tap the valve cover?

bbundy

I never see any issues until I take it to the track and flog the hell out of it on sticky tires with High G-loading. Then oil wants to come out every crank case ventilation orifice it can find fresh well working engine or not.

Bob