Proper crankcase evacuation is probably the most misunderstood system on an build today and it dosen't matter how experianced or famous a shop/builder/tech is, it is simply not understood.
The main reason most modify their OEM system is to eliminate the oil ingestion into the intake air charge. Many simply delete the system and releive pressure through breathers or (yes, short lived motors) open hoses. This is fine for releiving pressure and eliminating the path of ingestion, but if the suspended combustion by-products are not evacuated while still in a gasseous state then during cool down they condese and drop into the oil and then you begin the path to shrotened engine life.
The main culprits:
Abrasive carbon particles: Many are to small to be filtered out by the oil filter and as the content builds up the accelerated wear to the bearings, journals, and pistons strats to take its toll.
Water. Especcially with todays ethanol added fuels water is absorbed like a sponge and it mixes with other hydrocarbons to form sulfuric acid (get an engine oil analysis to see) which after so many PPM starts to etch the bearing and journal surfaces.
Contaminates and dilutes the oil and its ability to protect.
There are a ton more but these are the main damage causing compounds.
If you are not flushing and evacuating these out of the crankcase each time it is running at operating temp you are accelerating wear.
Now, a NA engine can be evacuated by the intake manifold vacuum alone, and with a properly designed oil separating catchcan installed on the "dirty side" of the PCV system, this is eliminated. The problem is most cans are nothing but any empty container with 2 fittings added so even though some oil will condense (same as a beer can) most is simply pulled right through and still causes detonation and carbon & gunk build-up.
Typical intake manifold from ANY modern car or light truck (yes, they all have this issue):
ALL claim to be the best, but here are some examples:
the can on the left is a popular one branded by a dozen or so companies...Mike Norros & CCA are 2. It draws in the vapors through the top, and there is a small chamber with scotchbrite material in that traps the oil that then drips down into the lower portion to be drained later. It works quite well and only lets a small amount through mainly due to the outlet being only 1" from the drops as they fall. The smaller drops do get sucked through and into the intake aircharge, but the majority is trapped. Good can.
The top one is from AMW and is near identical to the ELite in design.....works excellent.
The one on the right is an Ebay can and is just empty so most oil laden vapors just do a U turn and right out. Junk.
so is this totally empty but nice looking unit:
The far left is Billet Prototypes, Drevolution, DiabloSport, etc. All made by Billet Prototypes.
It is one of the best looking and quality second to none in appearance, but is one of the worst performing of all the well known units. Look at the top portion. It has the inlet & outlet in the same chamber separated by a divider with machine scrap (works well) as the coalesing material. This all works ine except it is on BOTH the inlet & outlet sides and as the vapors are flowing through, the saturated material just keeps the oil right at the outlet so it pulls right through. In tests it probably allows 30-40% of the oil to pull through. Simply remove one side and label it as the outlet and its function nearly doubles. When the motor is not running and there is no flow to pull the oil through the saturated material does drop the oil down into the bottom collection chamber and again, you will see oil caught, but its what gets through that you DONT want.
The RX can on the right has 7" between the inlet & outlet and the vapors enter the top center fitting, travel into the condensing chamber where the tube is perforated and dispreses the gasses to begine condensing, where they then are forced to the outer cooling surface and then have to work past the upper disc separating the outlet chamber. It then exits through a flow controlling oneway checkvalve that prevents the gasses from flowing to fast, and also prevents reversion or back-flow at WOT. This and the Siakou Micchi tested the most effective of allboth allowing no or almpst no detectable oil to pull through. To test any can, simply pick up a clear glass inline fuel filter from any autoparts store ($8-$12) and install it inline between any can outlet and the intake manifold and you can test any can for oil pull through and effectivness.
The cans we have tested and rate excellent are:
The RX performance is the only one with integrated flow controlling checkvalves and the only one made for turbo or front mount SC applications.The RX & Saikou Micchi both trapped all or nearly all the oil.
With a top mount SC this is an intercooler after 6k miles w/no proper can (Livernoise does not believe in catch cans and states this is good for the motor & SC:
As you can see, the amount of varnish and reidue build up has already in 6k miles insultated a good amount of the IC's ability to transfer heat and appears app 15% clogged/obstructed as far as air flow through so imagine 20-30k miles what the effects are.
A top mount SC does not pressurize the intake manifold so any NA can can work. The issue is at WOT where there can be some reversion if not checkvalve eqquipped. The other factor is the size of most cans will allow then to be overwhelmed if there is any substaintial boost as all motors have a certain amount of blow-by. So look at the larger capacity to be able to deal with the increased demands.
Now a turbo or front mount system will pressurize the intake manifold so this is where I see 99% done dead wrong. Even with a one way checkvalve, when under boost there is NO evac taking place and the excess crankcase pressure will force oil into the inlet side of the head unit and this causes several issues. First, the detonation issues from the oil ingestion.
Second, the turbine wheels are extremely fine balanced and any residue or varnish from the oil ingestion will cause the balance to become uneven and then your looking at shortened life.
Most turbo or front mount SC systems vent into the air filter and just compound this.
My solution is to use the RX Stage Two dual valve system. Theprimary valve allows the intake manifold to provide proper crankcase evac when not in boost, and as soon as it detects positie atmosphere in the intake it closes and the secondary valve opens using the turbine inlet suction. The can traps all the oil so at no time is there contamination, and the crankcase is properly evacuated during both boost & non-boost operation. We then use the RX flow controlling checkvalved breather and cap the OEM fresh air path so there is no oil entering via the "clean side".
Now, for the monster big boost builds there is their ultimate:
It dosent fit into tight spots, but with -8 or -10 AN fittings and hoses, high flow one way checkvalves, and over 1 qt capacity it has prevented any oil ingestion on even the wildest 21 plus #boost 1000 plus RWHP builds.
From here lets try questions and answers. I'm not here to sell anything, just share a lifetime of experiance & knowledge in the racing industry.
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