Are all vvt created equal.

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Each manufacturer designs their own. Overall they seem ok? Ford 5.4 comes to mind, but most are ok—timing chains seem more problematic.
 
besides reliability i would thing the range is most important for the most benefits
 
Cant speak for vvt on higher end German vehicles. I Never had any issues on a Toyota and only issue I heard of on a Honda is the vtec solenoid being troublesome. However the newer vvt's are not as hard hitting as the past they're more civilly tuned. I remember vtec from the late 90s early 2000s and you knew about it when vtec engaged. Even the old celica gt-s and Corolla xrs had a bang when vvt hit.
 
Lots of different terms and systems being thrown around in here.

VVT is variable valve timing. It changes the relationship of the camshaft(s) to the crankshaft (called phasing), allowing camshaft timing to change based on engine operating conditions. VVT is largely an emissions control strategy. There is some performance benefit in retarding and advancing camshaft timing at various points in the engine operating range but the biggest benefit is controlling emissions. You will rarely (if ever) have a dual-VVT engine with an EGR valve. Being able to control camshaft timing allows the introduction of exhaust gas to the intake stream through reversion. Again, small performance benefit, large emissions benefit.

VVT is pretty much the standard on all engines now. Every manufacturer uses vane-type actuators with oil control solenoids. Pretty standard stuff across the board. You'll see it called many things: VCT (Ford), VANOS (BMW), VVT-i (Toyota), AVCS (Subaru). They're all pretty much the same technology.

There is a different set of acronyms and names though: VTEC and iVTEC (Honda), VVTL-i (Toyota), i-AVLS (Subaru), MultiAir (Fiat), Valvetronic (BMW), etc. There are more advanced systems that typically also change camshaft lift and/or duration during engine operation. They all include VVT but go way beyond in terms of complexity and vary wildly in function, capability, mechanization, and reliability.
 
Lots of different terms and systems being thrown around in here.

VVT is variable valve timing. It changes the relationship of the camshaft(s) to the crankshaft (called phasing), allowing camshaft timing to change based on engine operating conditions. VVT is largely an emissions control strategy. There is some performance benefit in retarding and advancing camshaft timing at various points in the engine operating range but the biggest benefit is controlling emissions. You will rarely (if ever) have a dual-VVT engine with an EGR valve. Being able to control camshaft timing allows the introduction of exhaust gas to the intake stream through reversion. Again, small performance benefit, large emissions benefit.

VVT is pretty much the standard on all engines now. Every manufacturer uses vane-type actuators with oil control solenoids. Pretty standard stuff across the board. You'll see it called many things: VCT (Ford), VANOS (BMW), VVT-i (Toyota), AVCS (Subaru). They're all pretty much the same technology.

There is a different set of acronyms and names though: VTEC and iVTEC (Honda), VVTL-i (Toyota), i-AVLS (Subaru), MultiAir (Fiat), Valvetronic (BMW), etc. There are more advanced systems that typically also change camshaft lift and/or duration during engine operation. They all include VVT but go way beyond in terms of complexity and vary wildly in function, capability, mechanization, and reliability.

The Toyota A25A-FKS is a mainstream engine with Dual VVT-i (electric cam phasing on the intake cam) with a EGR valve.
https://parts.toyota.com/a/Toyota_2...UST-GAS-RECIRCULATION-SYSTEM/526430-2501.html
 
Cant speak for vvt on higher end German vehicles. I Never had any issues on a Toyota and only issue I heard of on a Honda is the vtec solenoid being troublesome. However the newer vvt's are not as hard hitting as the past they're more civilly tuned. I remember vtec from the late 90s early 2000s and you knew about it when vtec engaged. Even the old celica gt-s and Corolla xrs had a bang when vvt hit.
That's not VVT that you felt. It's the Toyota VTEC you felt on the VVTL-i system
 
My L96 (6.0 gasser) in my 1 ton has VVT. The previous generation LY6 had it as well. As far as I can tell it has been trouble free. People will sometimes eliminate it they are doing a cam swap. I don't plan on swapping the cam in my truck.
 
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