FIGS

iTrader: (11)

Hi guys, just though I would post up what our intake oil breathers look like after a full day of lapping at 88 degree ambient temps. Very little blow by as you can see. We use a thicker viscosity Amsoil Dominator competition oil to both reduce blowby and handle the escalated oil temps. Just thought I would post up,
We might do an inline filter off the valve covers so that any trace oil can drain back, but nothing alarming about blowby, its an indicator. Most oil viscosity suggestions by the OEM are to meet EPA startup emissions requirements and fuel conservation standards. Oil should be part of your tuning strategy and should be chosen based on your end use and environmental conditions. Catch cans are a part of this tuning strategy as an indicator of where the system stands. They are not a solution in that regard, unless you like losing compression and of course wasting oil

JDMV8

iTrader: (6)

Isn't the point of a catch can to combat losing compression? Increased air pressure due to oil vapors slow down piston movement. A catch can catches these vapors.
I guess a problem can occur if the catch can has a leak in the hosing or unit itself which disrupts the vacuum...or if it get filled to the brim.
I don't have a catch can, but higher viscosity oil wouldn't be a "fix" for me since I live in the NE region.

lobuxracer

iTrader: (2)

The point of a catch can is to reduce a low octane component in the cylinder. Oil has a very low octane, and sufficient oil vapors will cause detonation.

The source of your information does not understand much about engine physics or positive crankcase ventilation systems.

FIGS

iTrader: (11)

With multiweight oils you can get high viscosity while running with a lightweight starting viscosity, thus 0w40 might be a better solution for your situation. or change oil during colder months as the running temps will be lower.
A catch can is just a precipitator to remove oil from oil vapor when the crankcase is pressurized by excessive combustion pressure that passes the rings. The fact that there is blow by at all suggests that there is leakage around the rings reducing the compression.

JDMV8

iTrader: (6)

Okay. The thing is the intake hoses don't get much blow-by anyway. It's the pvc hoses that do...

I8ABMR

Every ISF to the brand new RCF with the AOS has filled these cans on the track. Pretty wild .

MileHIFcar

I know mine has been filling up about a quarter of the way about every 2-3 weeks..........So what is Figs saying?? That if you have an AOS and are filling it up you are having compression issues and ring issues??

MileHIFcar

This is what I should have quoted that Mike wrote?? Anybody want to chime in on this?

Justind27

iTrader: (6)

My moroso still bypasses oil, I'm changing the can a bit more to try to get the oil to stay low and tapping the bowl for the drain valve (ez oil drain valve for aircraft on Google should be about $23)

I8ABMR

All of ISFs and RCFs on the track have shown this. Your engine is fine. If Lobux and Mike bolted one up their cars would fill them up too.

My point here is , 95 % of the oil vapors get sucked through the PCV and not the intake and valve covers so the AOS will remove that really significant vapor.

Mike have you opened up your throttle body at a track day?? I see your point with the higher viscosity, but my concern would be that the oem bearing clearances are not designed to run thicker oil so while you have increased viscosity your flow rate will drop and lead to an increase in bearing temps since the temp should correlate with oil flow rate

FIGS

iTrader: (11)

when we ran 30w oil we saw significant oil on this side of the breather path, which is the baffled valve cover breather path. The PCV path contains trace amounts of oil as it should. But for those same people that are filling up canisters off the PCV I have to ask, did you have tangible oil consumption of the same magnitude before you chose to accumulate it? We have seen stable oil consumption, meaning the oil required to maintain proper oil levels and normal service intervals over the past 3 oil changes we have increased viscosity. The 50 wt oil is dramatic, but a step that we tool to ensure safe wear levels during elevated temps. Typically most of our race cars are running a 40 wt oil of some type, 5w40 or 15w40. The reason I show the breather side of the intake is that this is the larger indicator of blowby to me and something that we observed early on during testing, probably 5 yrs ago at this point. Pretty sure the CCS-R was not running 30 wt oil during its 25 hr race and it also appears to have maintained the PCV location adding a catch can to the breathers on the valve covers. I am just here to share our experience.

Justind27

iTrader: (6)

I've seen the exact results you are asking about. It's required a little bit of oil in between changes in the past (prior to using the Aos) but I was wondering about that can setup on the ccsr that gushi drove. I've always just ran mobile synthetic in factory weight.

Sylvan

iTrader: (6)

Basically he is trying to discredit his main competitors oil catch can, don't read anything more than that into this.

FIGS

iTrader: (11)

less than 1 qt, more than a qt? Just trying to have you guys think about the system as a whole and the sum of inputs/outputs. Those that have purchased or made catch cans have already spent the money so they have made their decision based on their own concerns. I talk more people out of spending money than not. catch cans will catch oil, but you also are changing the system to do so. as it sits the PCV will take oil back into the crankcase if it has accumulated on top of the valve based on their relative position. We run extended oil changes and do not see much oil consumption, again our experience.

lobuxracer

iTrader: (2)

Counterflow oil migration is common in any vacuum system and it a big problem in the high vacuum world because the oil wants to go to the place you want the fewest molecules. Seeing oil in the intake tube is no surprise to me.

The biggest question from my perspective is this - does your engine use oil between changes? Mine uses very little even with 12k mile OCI. This tells me the oil control rings on the pistons are doing their job, and the system as designed by Lexus is working well.

Any time you introduce a new element into an existing design things change. The AOS or any catch can does something the OEM system does not do - it condenses oil vapors after they have left the engine. There is extensive baffling inside the valve covers to do this as well, and the OEM unit underneath the intake is also designed to remove oil from the PCV flow and return it to the sump.

The things I learned in the gas analysis lab I operated taught me a few fundamental principles about gas behavior. First is, any gas that loses heat also loses pressure and volume (if the system is not fixed volume). Oil vapors are no different from any other gas. So the volume of liquid collected in any catch system is going to be different than what one would expect without it simply because it is cooler than the other parts of the system. Oil will collect and oil will migrate to this cooler spot in the system. Second, the total oil loss is easy to measure if you know how much you put in and when you put it in. So, in essence what Mike is saying is, we are not seeing a significant oil level drop, even during track use, which would make us believe there is anything about the OEM system which is being overwhelmed. I have also not seen this, and have been quite impressed by how little the oil level in my engine drops between changes every 12k miles.