NOAK evaporation and GDI engines

Originally Posted by Gokhan
Originally Posted by circuitsmith
Are PCV fumes entirely responsible for IVDs?
No, but the PCV oil mist (liquid-oil droplets) is responsible for most of the IVD. I can't post the whole Afton paper because of copyright issues, but I'll repeat its summary here. ---------------------------------------------------- Afton/SAE paper on IVD Formation of intake-valve deposits in gasoline direct-injection engines Gregory Guinther and Scott Smith -- Afton Chemical Corporation October 17, 2016 https://saemobilus.sae.org/content/2016-01-2252 I will put their conclusions here. IVD means intake-valve deposits. SUMMARY/CONCLUSIONS * A standardized, vehicle-based GDI IVD test has been developed that is both repeatable and responsive to known additive chemistry. * Higher engine loads lead to an increased rate of deposit formation. * IVD formation in this protocol is an oil-related process, and the majority of the oil that finds its way onto the intake valves comes from the PCV system. * The oil leaving the crankcase through the PCV system is whole oil containing additives and contaminants (not distilled base oil vapor which contains no additives). * PCV gas flow in the intake manifold is inconsistently distributed among the eight runners of the manifold leading to the valves. * Inhibiting the carbon-formation process lessens the rate of deposit formation on the intake valves. * Oil consumption past the rings bring both additive and nonadditive elements into the combustion chamber where they are incorporated into the exhaust-gas particles. * Particles found in EGR exacerbate deposit formation rate. * Particles found in EGR appear to incorporate combusted oil additive components, engine wear metals, and ambient air contamination. Gregory Guinther and Scott Smith Afton Chemical Corporation Note the conclusions I highlighted. They are saying that the main source of the intake-valve deposits is PCV. However, it's liquid oil (whole oil) coming through PCV as a mist, not evaporated oil (oil vapor). So, the amount of oil coming through PCV has nothing to do with the Noack volatility.
So does this mean that a catch can will help? I had one on my Kia Optima until, according to the dealer, it wore a hole in the a/c line.
 
The study Gokhan posted makes sense. I can see how Valvoline Modern Engine would work if they designed it with a unique, special detergent that when the "whole" oil gets in contact with the IV's, it helps clean them. That's they mechanism behind this oil.
 
Originally Posted by Mad_Hatter
How then do exhaust valves manage to stay relatively clean and why wouldn't the engine builder just slightly modify the IV lift profile to address this in CVVC's..if it were just that???
Exhaust valves get hot enough to burn off any deposits. IV lift profile won't change things if the intake manifold has vacuum and the combustion chamber is near atmospheric at the beginning of the intake stroke.
 
Is this new theory or additive/detergent that Valvoline has which can "wash/clean" ivd, part of any (api, etc.) cert? Are others failing this test? Or is this getting into oil is not oil territory? lol
 
Originally Posted by OilUzer
Is this new theory or additive/detergent that Valvoline has which can "wash/clean" ivd, part of any (api, etc.) cert? Are others failing this test? Or is this getting into oil is not oil territory? lol
I haven't read any UOA or VOA on Modern Engine, that gets identified in the analysis as something different / special. I always thought the difference between Modern Engine and Advanced was in the Modern Engine base oil.
 
Originally Posted by Triple_Se7en
Originally Posted by OilUzer
Is this new theory or additive/detergent that Valvoline has which can "wash/clean" ivd, part of any (api, etc.) cert? Are others failing this test? Or is this getting into oil is not oil territory? lol
I haven't read any UOA or VOA on Modern Engine, that gets identified in the analysis as something different / special. I always thought the difference between Modern Engine and Advanced was in the Modern Engine base oil.
No the difference is the detergent they are using. It's proprietary. If you look at the VOA, it only has 79ppm of moly. No other visible metallic additives so the SA is also probably quite low. Not sure about the base oils.
 
Originally Posted by buster
Originally Posted by Triple_Se7en
Originally Posted by OilUzer
Is this new theory or additive/detergent that Valvoline has which can "wash/clean" ivd, part of any (api, etc.) cert? Are others failing this test? Or is this getting into oil is not oil territory? lol
I haven't read any UOA or VOA on Modern Engine, that gets identified in the analysis as something different / special. I always thought the difference between Modern Engine and Advanced was in the Modern Engine base oil.
No the difference is the detergent they are using. It's proprietary. If you look at the VOA, it only has 79ppm of moly. No other visible metallic additives so the SA is also probably quite low. Not sure about the base oils.
What detergent are they using that nobody else is using? What detergent cannot be identified by Blackstone, Polaris.......etc?
 
Originally Posted by Triple_Se7en
What detergent are they using that nobody else is using? What detergent cannot be identified by Blackstone, Polaris.......etc?
Anything that isn't metallic, especially a transition metal. Without that it's not going to show up on an ICP. Phosphorus is a metalloid of sorts and can be detected. Even when it is metallic you only see the metal itself (nothing about a compound), and of course you only see those metals that are tested.
 
^ right. Anyone's guess. There was a patent on some of the research they did on it. I think it's been posted before.
 
Originally Posted by circuitsmith
Originally Posted by Mad_Hatter
How then do exhaust valves manage to stay relatively clean and why wouldn't the engine builder just slightly modify the IV lift profile to address this in CVVC's..if it were just that???
Exhaust valves get hot enough to burn off any deposits.- and that's where I was going with bringing up the exhaust valve. I don't then see how is it those same very high temp exhaust gasses are depositing on the IV? Unless the exhaust gasses are somehow "cooking" oil already on the IV's? IV lift profile won't change things if the intake manifold has vacuum and the combustion chamber is near atmospheric at the beginning of the intake stroke. - fair point. I think. Maybe overlap at the beginning of stroke 1? But maybe the delta would still be too great..dunno.
 
Short of having a GDI / PFI hybrid injection system to spray the backs of intake valves - best you can do is use a lower NOACK oil with low VII's and low SAPS and keep OCI's on the shorter side (under 5K miles) . *For my Hyundai 2.4L GDI engine I will next fill start using Valvoline Advanced 5W30 (lower in VII's than M1 but slightly higher than M1 in ash) . Valvoline Advanced still has slightly lower VII's than Pennzoil Platinum (not sure about ash though) … I don't think Castrol is even in the conversation as the base oils Castrol uses for USA bound oils are simply not that great of quality (VII content is highest among M1 , PP , QSUD and Valvoline Advanced - NOACK not great either on the Castrol oils) .
 
Originally Posted by ChrisD46
Short of having a GDI / PFI hybrid injection system to spray the backs of intake valves - best you can do is use a lower NOACK oil with low VII's and low SAPS and keep OCI's on the shorter side (under 5K miles) . *For my Hyundai 2.4L GDI engine I will next fill start using Valvoline Advanced 5W30 (lower in VII's than M1 but slightly higher than M1 in ash) . Valvoline Advanced still has slightly lower VII's than Pennzoil Platinum (not sure about ash though) … I don't think Castrol is even in the conversation as the base oils Castrol uses for USA bound oils are simply not that great of quality (VII content is highest among M1 , PP , QSUD and Valvoline Advanced - NOACK not great either on the Castrol oils) .
What does VII's stands for? viscosity index? again somebody needs to educates me LOL my mazda calls for 0w20, is valvoline as good specs in 0w20?
 
Valvoline is a good choice too. I'd put M1 EP/AP 0w20/5w20 at the top, followed by Pennzoil Platinum, then Valvoline. For boutique, I'd use Driven GDI 0w20. SA is .72.
 
Originally Posted by buster
Valvoline is a good choice too. I'd put M1 EP/AP 0w20/5w20 at the top, followed by Pennzoil Platinum, then Valvoline. For boutique, I'd use Driven GDI 0w20. SA is .72.
Which specs is it better on Pennzoil Platinum vs Valvoline that you like better? IIRC, PP has an SA about 1.3%. But that was a few years ago.
 
Originally Posted by wolf_06
Originally Posted by ChrisD46
Short of having a GDI / PFI hybrid injection system to spray the backs of intake valves - best you can do is use a lower NOACK oil with low VII's and low SAPS and keep OCI's on the shorter side (under 5K miles) . *For my Hyundai 2.4L GDI engine I will next fill start using Valvoline Advanced 5W30 (lower in VII's than M1 but slightly higher than M1 in ash) . Valvoline Advanced still has slightly lower VII's than Pennzoil Platinum (not sure about ash though) … I don't think Castrol is even in the conversation as the base oils Castrol uses for USA bound oils are simply not that great of quality (VII content is highest among M1 , PP , QSUD and Valvoline Advanced - NOACK not great either on the Castrol oils) .
What does VII's stands for? viscosity index? again somebody needs to educates me LOL my mazda calls for 0w20, is valvoline as good specs in 0w20?
Viscosity index improvers. polymers used to increase the viscosity index of a formulated engine oil. Less of these is considered to be better for deposit control and extreme pressure performance. They can be used as a crutch to prop up a thin base oil mix. They tend to leave deposits on piston rings and don't hold up well to extreme pressure without temporary and permanent breakdown. Keys to look for is oils with a viscosity index of 170 or less and a lower viscosity spread between winter and kinematic viscosity, som0w3 in not better than 10w30 unless the cold weather pump ability of0w30 is needed.
 
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*It could be now that Valvoline Advanced Synthetic could be better than PP Synthetic in ash content and already know it beats PP in VII % content . Still, PP would be my 2nd choice followed by M1 .
 
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