02-07-2024, 08:36 AM | #1 |
Drives: 2010 Camaro Join Date: Nov 2009
Location: Denver
Posts: 1,383
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Oil ingestion issues and the proper way to address them
A breather cap, while the unit you have has a ball valve to prevent unmetered air from entering, does just the opposite of what a proper PCV or crankcase evacuation system needs to function properly. You never want to vent to the engine compartment for several reasons, safety being #1. Flammable vapors vented into a hot engine compartment create an extremely dangerous fire risk. From hot headers to stray spark. Today’s GDI engines experience an excessive amount of raw fuel pushed past the rings into the crankcase, and mixed with the oil vapors create a very volatile mix of flammable/explosive gasses and that is part of why no form of Professional Racing does this antiquated way of dealing with pressure. All now use a vacuum system on the crankcase so pressure cannot build in the first place. Back in the 1960's-1980's venting was universal for racing applications but the safety aspects and the negative impact on everything from power produced in the short term, and excessive wear and damage to internal parts for the long term, dictated using science and technology for a far better solution. But the aftermarket street crowd has taken this outdated method and has ignored all aspects of a proper crankcase evacuation system resulting in tons of confusion and premature engine failures.
All PCV systems have several functions that are for engine longevity and only one is emissions related. Every ICE (internal combustion engine) produces some blow-by. And here is where the self-taught assumptions come into play, most tuner shops simply stop the thought process at the pressure that results. They never wonder what is contained in that blow-by and how it affects the engine. So first, is piston ring seal. Today’s low tension piston rings are very thin and require pressure above them and suction below to maintain stability and proper seal as this holds them against the ringlands. When pressure builds, it pushes the rings up from the bottom and they enter a state of rapid vibration known as ring flutter. This increases blow-by and decreases power made. So, a negative in every way. But venting for the reasons already listed above never results in zero pressure in the crankcase so it is a very poor way to address this. The stock routing this pressure releases into the main intake air tube so no flammable vapors escape into the engine compartment. That is fine with the average daily driver that rarely sees hard acceleration or WOT operation. But a proper system maintains vacuum suction on the crankcase at all times. Pressure can never build when a proper amount of vacuum suction is pulled but the stock PCV systems only use intake manifold vacuum for this suction, and when accelerating or at WOT, there is no IM vacuum present, and this is when pressure will build. So, the simplified thinking is open the crankcase and vent as they used to do in the "old days". But that brings us to the next function. Contained in the blow-by are these substances: Water, Acids, Raw Fuel, and abrasive particulate matter (ash, soot, and carbon). These are all harmful to the engine attacking the metals, causing far more wear and overwhelming the engine oil’s ability to protect. Today’s full synthetics don't so much "wear out" but become overwhelmed with these contaminants. If not flushed and removed (sucked out/evacuated) they quickly settle and accumulate mixing with the oil. So, the incoming fresh filtered MAF metered air is drawn from the main intake air tube, and this creates a direct path for oil to simply be drawn into the air intake and thus the supercharger. So, our billet CSS has a internal coalescing chamber with stainless mesh coalescing media to trap that oil if pressure exceeds the vacuum generated by our billet Venturi Vacuum Generator. It generates from 7-14" of vacuum so when the IM vacuum drops, the Venturi takes over providing full time vacuum at sufficient levels to prevent pressure from building to begin with. The check valves prevent any pressure back flow and gives the same benefits as a belt driven vacuum pump system, but for the street (except CA). So yes, you do need the CSS to prevent what you’re experiencing. Let me know if you have more questions as this has not been taught in decades and very few understand it outside of the Automotive Engineering or Professional racing World. |
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