VVT Engines and Best Engine Oils ?

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Where does it say about thinner oils being best for VVTI? It talks about the passages being small but that doesn't mean that thin oil is required for this. I ran 30wt in a spec'ed 20wt engine with VVTI with 0 issues.
 
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It's true- a lubricant with extremely low viscosity is great for efficiency, but leaves many things desired for longevity. There are certain mechanical properties of the ICE that still greatly exceed the physical capabilities of current engine oil technology. Extremely thin oil and the pressure spike right at TDC are two things that don't play nice together.
 
I miss the old vtec where you knew vtec was singing. Vvt just doesn't have that in your face kick.
 
You would think if any issues it would be at cold temperature startups as oppose to operating temperatures. Therefore the x (xWy) should play a bigger role than y if any....
Even then, the experts always say if the oil is "pumpable" it doesn't matter and they disregard the cold temp oil flow videos. I still don't understand this part quit well!

If the gaps are really paper thin x2 then sludge or deposit should play a bigger role.
 
Originally Posted by ChrisD46
Interesting article suggesting premium oils / oil filters and possibly oils on the thinner side are best for VVT engines - your thoughts ? http://oil-synthetic.com/2017/01/18/variable-valve-timing-improves-engine-efficiency/


My thought is if VVT engines were that sensitive to oil viscosity, then better not ever "kick the VVT in" until the oil hits 200 F. Ever hear of a VVT engine throwing codes or having issues if someone relined the engine with 5W-20 that was only at 100F, which is thicker than a 5W-50 at 200F ?

That article is saying that keeping the engine clean inside (by using good oil and filter, and regular maintenance) is important so the tiny passages that operate the VVT don't clog up and cause problems.
 
Originally Posted by ZeeOSix
Originally Posted by ChrisD46
Interesting article suggesting premium oils / oil filters and possibly oils on the thinner side are best for VVT engines - your thoughts ? http://oil-synthetic.com/2017/01/18/variable-valve-timing-improves-engine-efficiency/


My thought is if VVT engines were that sensitive to oil viscosity, then better not ever "kick the VVT in" until the oil hits 200 F. Ever hear of a VVT engine throwing codes or having issues if someone relined the engine with 5W-20 that was only at 100F, which is thicker than a 5W-50 at 200F ?

That article is saying that keeping the engine clean inside (by using good oil and filter, and regular maintenance) is important so the tiny passages that operate the VVT don't clog up and cause problems.


That makes sense. Does the vvt kicks in when the car has warmed up? That would be a good design!

Either way you would think they design the engine to handle the oil viscosity issues except the sludge or deposits which can clog up tiny passages.
 
Doesn't Chrysler have a vehicle model where they specify a viscosity for this very reason?

I can't remember the model. Was it the 300?
 
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simply put vvt is not affected by viscosity or oil temps. the solenoid requires oil pressure. i guess with engine management vvt could be deactivated until the engine is at a safe operating temp.
 
Originally Posted by Oildudeny
I miss the old vtec where you knew vtec was singing. Vvt just doesn't have that in your face kick.


Off topic a little:

That's because VVT simply changes cam timing and not lift or duration. Those of us who hot-rodded engines for years understand the true capability of "big cams" vs. re-timed emissions cams.

For example, it was common for 1800cc engines to produce a real world 250HP. Such as variants of the Cosworth BD engines. These were fire breathing monsters, with some righteous cam profiles. Fast forward to Honda's VTEC, and the 2000cc/240 HP engine was not far off the mark. It took aggressive cam profiles to make that happen, not VVT.


The BD series of engine, designed in the late 1960's should look familiar to many of us, as it's the basis for many modern designs.

[Linked Image]


FYI, Ford's VVT has a strong tendency to fail with the use of uber thin oils. Here in South Florida, Ford tech have discovered that higher viscosities result in longer cam phaser life. The speculation is that the thin oils and particulates wear the phasers our more rapidly, leading to an annoying knock.

I use M1 10W-30 and 10W-40 (depending on season) in my 5.4L Ford V8, 120,000 miles, and no phaser knock. I've done better than my neighbors, many of whom have had phasers replaced at least once, sometimes twice.
 
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Good old Ford, home of the 6.0 PSD customer based engine durability test!
mad.gif
I've wondered how VVT-i engines shear oil fairly badly, I always assumed it was timing chain related, but there must be VVT issues with them as well. I know my xB isn't a fan of anything thinner than 5W30.
 
No VTEC issues running xw-40 oils in my Odyssey which specs 5w-20. Can't even tell the difference. But then it isn't true VVT as it uses a separate intake cam profile to change the lift/timing.
 
Originally Posted by ChrisD46
Interesting article suggesting premium oils / oil filters and possibly oils on the thinner side are best for VVT engines - your thoughts ? http://oil-synthetic.com/2017/01/18/variable-valve-timing-improves-engine-efficiency/


That is not what the link says, instead
Quote
AMSOIL synthetic motor oil resists ......... It also resists viscosity loss, meaning it consistently performs the duties of a hydraulic fluid, which is vital to proper operation of VVT components.

... which implies too low an operating viscosity in the "VVT hydraulic fluid system" could lead to improper VVT operation.
In other words, higher operating viscosity is preferred in VVT system.
 
Originally Posted by OilUzer
You would think if any issues it would be at cold temperature startups as oppose to operating temperatures.

No as I understand it, VVT activation is not oil temperature dependent.
Instead it's engine rpm dependent. CMIIMW.

Quote
Therefore the x (xWy) should play a bigger role than y if any....
Even then, the experts always say if the oil is "pumpable" it doesn't matter and they disregard the cold temp oil flow videos. I still don't understand this part quit well!

I would advocate a higher y in 30 or 40 is perferred to 20 at sustained high rpm high load and hence high oil temperature regimes, never mind if it's x is 0, or 5 or 10.
 
*My assumption (perhaps wrong) was that the VVT passages were the thickness of two sheets of paper .
Originally Posted by StevieC
Where does it say about thinner oils being best for VVTI? It talks about the passages being small but that doesn't mean that thin oil is required for this. I ran 30wt in a spec'ed 20wt engine with VVTI with 0 issues.
 
My dad has a Dodge Caravan (2012) with over 300K on it and it has VVT and it has seen conventional it's whole life in the 5w30 variety with a basic fram filter cartridge. It was a fleet vehicle most of its life and saw lots of extended periods of idling. It calls for 5w20. It's running perfectly.

My mom has a 2015 Dodge Journey 2.4L with about 100K and it gets bottom basic 5w30 and a fram filter even though it calls for 5w20 and it also have VVT. No issues to report.
 
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