Oil Catch Tank

[ArthurPE]

Iv always believe it to be blowback coming from the Cylinders, maybe the valved are opening slightly during detonation...any way.

the intake are open, but during exhaust
they overlap with the intake, internal EGR

disconnecting the vents on the valve covers and putting filters to atm won't help...(plug cyclone so you don't have a vacuum leak)
try it
as I said I put filter media in the cyclone discharge, no oil vapor...
the cyclone is very effective...

the oil is primarily from the valve seals....and probably blow-by being burned onto the valves...but I doubt it's getting by the valve cover baffles, the long hoses (condenses and drains back into the baffle) and the cyclone seperator...

[JackS4]

What is the informed opinion of when the inlet valves are most susceptible to carbon build-up eg start-up, stop/start driving etc ?

J

[P_G]

I suspect both of what you have said and at higher temperatures say 110 degrees upwards but I am no scientist when it comes to these things.

[caldy]

Caldy have you inspected your valves since having the manifold De-vaned?

Yes, after 2k miles and there was a small amount of build-up, but probably no better/worse than when the vanes were installed.

[ArthurPE]

What is the informed opinion of when the inlet valves are most susceptible to carbon build-up eg start-up, stop/start driving etc ?

J

my 'guess'
high load/high rpm scenarios
stop-go traffic

start-up and warm-up not so much, valaves aren't hot, low blow-by due to the engine being 'nursed' until warm

[silverRS4]

I did a small experiment... I took some filter gauze stuffed/secured it into the cyclone to intake hose...after 200 miles+ no oil stains, not a tinge...

What exactly is the 'cyclone-to-intake hose' you talking about? The discharge is not a hose. It exits directly into the manifold (see the tapered silver discharge of item B below). So either you stuffed your gauze in the wrong place, or you placed it upstream of the cyclone. In that case, while you know full well that the cyclone has a limited volumetric flow tolerance, you make conclusions on its effectiveness after confessing to obstructing the flow path. While I agree that the crankcase ventilation and separator works as designed on the RS4, I think your little test was not properly arranged. Here's a pic showing the items of interest. Note that hose (2) is the only source of fresh air into the crankcase. Its supply point is a connection on the air duct hose between the mass air sensor and the throttle body (not shown).

[ArthurPE]

first: I put gauze in the lines from valve covers to the cyclone
a tinge of oil, the hoses are easily disconnect and generally are dry

second: sandwiched between A and B, no oil what so ever...at least for >200 miles before I pulled it

regardless, the deposits have no impact on performance and are a natural consequence of the design...

the cyclone actually has a very wide operating range...by design
3 cyclones in parallel sequenced by a spring loaded piston valve...

if that much oil were being inhaled:
you'ld have massive oil consumption, most cars use none
you'ld have smoking
carboning in the cylinders/pistons
emmission problems/cat failures

I know we want to beleive there is a 'problem', there's $$$ in it for some...

we want to believe porting a manifold will make more power, not in this engine...even extrude honing wouldn't make a difference...

3 ways to get more ooomph out of this motor:
bore and/or stroke
forced induction
compression ratio: see stroke above

the car is perfectly fine as it is....unless it's setting codes, etc., don't sweat it

[silverRS4]

first: I put gauze in the lines from valve covers to the cyclone..a tinge of oil, the hoses are easily disconnect and generally are dry

Since the dozens of times you’ve posted your test included the words ‘simple’ and ‘hose’, this is where I thought you stuck the gauze. I’m glad that’s now cleared up. See Art, pictures are helpful!

second: sandwiched between A and B, no oil what so ever...at least for >200 miles before I pulled it

Really? There are several hours of work to separate that connection. It’s not exactly simple and there are no hoses. Again, pictures are really helpful. Snap a few the next time you turn a wrench and I’d be glad to help you share them on a forum.

I know we want to believe there is a 'problem', there's $$$ in it for some...

This thread is about the benefit of a catch-can, right? I’ve been stating for over a year now (especially after Pippyrips trial) that the factory separator works fine and the amount of oil vapor in most RS4’s crankcase ventilation system is normal. I’ve mentioned twice in this thread. Who exactly are you arguing with?

we want to believe porting a manifold will make more power, not in this engine

Oh, I get it now. I post helpful pictures on a forum based on a continent that I don’t live on so people send me their manifold for a port job. Actually MRC Tuning does a great job with that and they are a tad more convenient for the folks on this forum. Maybe I like posting pictures because they help RS4 owners on this forum understand how their car works. Words alone can sometimes lead to confusion; especially if you spend too much time typing them and not reading them!

[ArthurPE]

Since the dozens of times you’ve posted your test included the words ‘simple’ and ‘hose’, this is where I thought you stuck the gauze. I’m glad that’s now cleared up. See Art, pictures are helpful!

Really? There are several hours of work to separate that connection. It’s not exactly simple and there are no hoses. Again, pictures are really helpful. Snap a few the next time you turn a wrench and I’d be glad to help you share them on a forum.

This thread is about the benefit of a catch-can, right? I’ve been stating for over a year now (especially after Pippyrips trial) that the factory separator works fine and the amount of oil vapor in most RS4’s crankcase ventilation system is normal. I’ve mentioned twice in this thread. Who exactly are you arguing with?

Oh, I get it now. I post helpful pictures on a forum based on a continent that I don’t live on so people send me their manifold for a port job. Actually MRC Tuning does a great job with that and they are a tad more convenient for the folks on this forum. Maybe I like posting pictures because they help RS4 owners on this forum understand how their car works. Words alone can sometimes lead to confusion; especially if you spend too much time typing them and not reading them!

sound advice: perhaps you should practice what you 'preach', because this deposit non-issue has taken on religious fervor, lol

or if they are intentionally misleading/disingenuous for ulterior motives: to sell something...reminds of the gold plated speaker cable debate...

I stand to make not a $ off modding or fixing 'problems' associated with this car...can you say the same?

[ArthurPE]

to summarize, IMO, there are 2 mechanisms casuing the deposits (whether they affect performance is another issue):

one is valve seal leakage, it can't be avoided, some oil must be allowed to get thru the seal to lube it, they are DESIGNED to do so...

second, internal EGR, as the hot gas (with some fuel) contacts a cool valve, deposits form, it will even affect some of the closed valves depending on volume

I think why more deposits seem to form closer to intake is that the valves are closer/cooler...

blow-by vapor would have oil in a liquid (vs gaseous) state entrained so would carry thru to the chamber and be burned, in addition it is in very small quantities...the blow-by is oil mist from the crankcase that is blown back up the head drain galleys by leaking compression (blown-by the rings), it is NOT oil flashed to a gas...

since it is liquid, it is easy to seperate, thru the baffles & cyclone, plus gravity in the tubes/conduits...if it wasn't droplets of liquid vs gas, cyclones would be useless...you would need condensors

the oil is not real hot...how do we know this? Audi heats the mixture to avoid freezing the water in solution (another natural consequence in any engine)

with the engine running put a temp probe over the valve cover vent
even contaminated oil will have a flash point >350F or so, usually >400F
the crankcase oil in these cars is ~200F, and THAT is where the mist comes from...even spray from the underside of the piston <300F
so the oil is not being 'boiled' off and being sucked into the engine...

[ArthurPE]

oil catch can/RS4 ~4:50 http://www.youtube.com/watch?v=sGKvHUpzMjk

but what is really going to impact deposit formation is the water/meth injection


it looks like he plugged/bypassed the cyclone...hmmmmm

you don't need to remove the manifold to get to the cyclone:
disconnect the hoses (quick-connects)
remove the cover bracket
slip whatever the valve over it is off its mntg stud
remove the cable clipped to it and the one in a clip on it
remove the 3 iirc, screws that secure it (don't drop them, tight work)
it pulls right out
maybe 15 minutes or so (finnegling the screws is the variable)

[P_G]

Out of curiosity what is the flash point of the typical 5W-30 oils like Castrol Edge, Fuchs Titan GT1 and Mobil 1?

It is been suggested to me to use Royal Purple, something ArthurPE may be familiar with as it originates in the US which supposedly has a higher flash point and is better synthetically which may reduce the carbonisation?

What is the general consensus?

[pippyrips]

Out of curiosity what is the flash point of the typical 5W-30 oils like Castrol Edge, Fuchs Titan GT1 and Mobil 1?

It is been suggested to me to use Royal Purple, something ArthurPE may be familiar with as it originates in the US which supposedly has a higher flash point and is better synthetically which may reduce the carbonisation?

What is the general consensus?

SR-71 had a few oil changes samples analysed - pretty sure after 4-5k miles it was below 100 degrees c.

[ArthurPE]

Out of curiosity what is the flash point of the typical 5W-30 oils like Castrol Edge, Fuchs Titan GT1 and Mobil 1?

It is been suggested to me to use Royal Purple, something ArthurPE may be familiar with as it originates in the US which supposedly has a higher flash point and is better synthetically which may reduce the carbonisation?

What is the general consensus?

SR-71 had a few oil changes samples analysed - pretty sure after 4-5k miles it was below 100 degrees c.

really?
that is below the boiling point of water...

Royal Purple is not oem approved but it is API approved so it should not void the warranty...

http://www.royalpurple.com/prod-pdfs/motor-oil-ps.pdf

flash point 5W40 ~425F

Castrol SynTec 5W40 ~ 400F

diluted with fuel/water/contaminants I bet the lowest either would get is 350F or so...at a 5k mile change interval and a car that is broken in...

this all depends on service: traffic or highway, etc.

[Terry1948]

I was just wondering, when I drive the car for a journey and arrive home and switch off and then the next day start her there appears to be very little smoke on start up but if when I get home Stop it and then later have to move it just up the drive the next time it appears to smoke a lot more it is blueish smoke so does this mean oil is running down the valve guides and causing more build up? also when I decoke it should I use diet coke or full fat coke!!