Vvt And Afm - S-10 Forum
S-10 Forum is the resource on GM S-series trucks, Suspension, engine information, Body Modifications, painting tutorials.  Modifications to suit every need, budget and whim

Vvt And Afm

Go Back   S-10 Forum > Engine and Drivetrain Tech > LSx Discussion
New User? Register Forgot Password


 
LinkBack Thread Tools
Old 03-17-2009, 12:18 PM   #1
Registered User
 
OUTLAW525YUP's Avatar
 
Age: 31
Join Date: May 2007
Posts: 84
Location: Red Deer Alberta CANADA!
User is: OffLine
Question Vvt And Afm

So I was thinking last night, who thinks it would be possible to combine the vvt of the l92 truck engine and the afm system, I know the afm option is only available with the auto trans but I think it would be a great idea to try. put the comp cams vvt cam in it put out 500 hp then throw in afm and have a vvt 250 hp v4. It should get great milage with the 6spd manual. Any tuning gurus out there please chime in.
P.S. I went and pulled the lifter valley off my 6.2 and the bosses and holes are drilled for the afm manifold.

Last edited by OUTLAW525YUP; 03-17-2009 at 12:19 PM. Reason: more info
Old 03-17-2009, 01:07 PM   #2
Registered User
 
chevysten's Avatar
 
Age: 50
Join Date: Dec 2007
Posts: 841
Location: Huffman TX
User is: OffLine
Re: Vvt And Afm

Maybe try ls1tech.com There is a few guys that I know of that get more into detail.Not saying anybody on here cant.
Old 03-17-2009, 01:25 PM   #3
LSx and V8 Mod
 
SweetS10V8's Avatar
 
Age: 36
Join Date: May 2004
Posts: 4,204
Location:
User is: OffLine
Re: Vvt And Afm

I know all about this.....Wont work,

AFM lifters are different and can not deactivate over .500 lift. AFM isnt worth it. VVT is awesome!

Last edited by SweetS10V8; 03-17-2009 at 01:27 PM.
Old 03-17-2009, 02:03 PM   #4
Registered User
 
jnoehl's Avatar
 
Age: 27
Join Date: Mar 2007
Posts: 365
Location: New Orleans, La
User is: OffLine
Re: Vvt And Afm

Quote: Originally Posted by OUTLAW525YUP
It should get great milage with the 6spd manual.
i wouldn't know about combining them, your talking seriously technical their. but i do know there is no way it would work on a manual trans, AFM components would get torn up by the manual.
Old 03-17-2009, 02:10 PM   #5
S-series Member
 
lilsonoma's Avatar
 
Join Date: Oct 2007
Posts: 532
Location:
User is: OffLine
Re: Vvt And Afm

Interesting read.

Quote:
Variable Valve Timing
The Gen IV Vortec 6.0Ls bring GM Powertrain’s industry exclusive cam-in-block variable valve timing (VVT), or cam phasing, to the small block V-8. VVT eliminates the compromise inherent in conventional fixed valve timing and allows a previously unattainable mix of low-rpm torque, even torque delivery over a broad range of engines speeds, and free-breathing high-rev horsepower. The cam-phasing system in the Vortec 6.0Ls is similar in concept to that introduced in GM’s 3.9L and 3.5L V6 car engines for 2006.

The Vortec 6.0L’s dual-equal cam phaser adjusts camshaft timing at the same rate for both intake and exhaust valves. A vane-type phaser is installed on the cam sprocket to turn the camshaft relative to the sprocket, thereby adjusting the timing of both intake and exhaust valve operation. The vane phaser is actuated by hydraulic pressure from engine oil, and managed by a solenoid that controls oil pressure on the phaser. The phaser uses a wheel or rotor with four vanes (like a propeller) to turn the camshaft relative to the cam sprocket, which turns at a fixed rate via chain from the crankshaft. The solenoid directs oil to pressure points on either side of the four phaser vanes; the vanes, and camshaft, turn in the direction of the oil flow. The more pressure, the more the phaser and camshaft turn. The Vortec 6.0L’s new E38 engine control module (below) directs the phaser to advance or retard cam timing, depending on driving demands. The dual-equal phaser system has the authority to retard the camshaft by up to 52 crankshaft degrees.

The benefits are considerable. The cam phaser changes valve timing on the fly, maximizing engine performance for given demands and conditions. At idle, for example, the cam is at the full advanced position, allowing exceptionally smooth idling. Under other operating demands, the phaser adjusts to deliver optimal valve timing for performance, drivability and fuel economy. At high rpm it might retard timing to maximize airflow through the engine and increase horsepower. At low rpm it advances timing to increase torque. Under a light load (say, casual everyday driving), it can retard timing at all engine speeds to improve fuel economy. Without cam phasing, a cam design must be biased toward one strength or another—high-end horsepower or low-end torque, for example—or profiled at some median level that maximizes neither.

Variable valve timing allows linear delivery of torque, with near-peak levels over a broad rpm range, and high specific output (horsepower per liter of displacement) without sacrificing overall engine response, or drivability. It also provides another effective tool for controlling exhaust emissions. Because it manages valve overlap at optimum levels, it eliminates the need for an Exhaust Gas Recirculation (EGR) system.

Finally, cam-phasing helps maximize the fuel-saving benefits of Active Fuel Management technology (below). The cam phaser can adjust valve-timing for maximum torque when the Vortec 6.0L is operating as a V4, keeping the engine in this fuel-saving mode as long as possible.

The Positive Crankcase Ventilation (PCV) system now incorporates a larger 2.75mm flow orifice and, to aid assembly, has quick-connect fittings for the connections on the engine.

Active Fuel Management
The L76 aluminum-block Gen IV Vortec 6.0Ls feature GM’s Active Fuel Management technology (AFM). AFM temporarily de-actives four of the 6.0L’s cylinders under light load conditions. It increases fuel economy approximately 6 percent under the federal government’s required testing procedure and potentially more in certain real-world driving conditions. Yet truck owners don’t have to compromise on the Vortec 6.0Ls outstanding peak horsepower to go farther on a tank of gas.

Active Fuel Management stems from a simple premise: most truck owners have more power than they need much of the time. Many choose powerful V-8 engines to be prepared for the occasional heavy load, but during routine commuting that powerful engine operates at a fraction of its capability. Volumetric efficiency is impaired, and that means less than optimal fuel mileage. AFM offers a common-sense solution. It saves fuel by using only half of the Vortec 6.0L’s cylinders during some driving conditions, and seamlessly reactivates the other cylinders when a driver demands full power for acceleration or load hauling.

Managed by the new E38 engine control module (ECM), AFM automatically shuts down every second cylinder, according to firing order, during light-load operation. In engineering terms, this allows the working cylinders to achieve better thermal, volumetric and mechanical efficiency and lowering cyclical combustion variation from cylinder to cylinder. As a result, AFM delivers better fuel economy and lower operating costs. Perhaps the most sensible thing about AFM is that it harnesses the engine’s existing capabilities, starting with the potential designed into the E38 ECM. The only mechanical components required are special valve lifters for cylinders that are deactivated, and their control system. Active Fuel Management relies on three primary components: De-ac (for deactivation) or collapsible valve lifters, a Lifter Oil Manifold Assembly (LOMA), and the ECM.

One of the most sophisticated engine controllers, the E38 ECM (below) measures load conditions based on inputs from vehicle sensors and interprets that information to manage more than 100 engine operations, from fuel injection to spark control to electronic throttle control. AFM adds an algorithm to the engine control software to manage cylinder deactivation and reactivation. When loads are light, the E38 automatically closes both intake and exhaust valves for half of the cylinders and cuts fuel delivery to those four. The valves re-open to activate all cylinders when the driver demands brisk acceleration or full torque to move a load. The engine’s electronic throttle control (ETC) is used to balance torque following cylinder deactivation or reactivation. The transition takes less than 20 milliseconds, and is virtually indiscernible to most drivers.

Valve lifters are operated by the engine’s camshaft, and lift a pushrod that operates the valves in the cylinder head. In the Gen IV Vortec 6.0L, the De-ac lifters are installed in cylinders 1, 4, 6 and 7, while the remaining cylinders use conventional lifters. The hydraulically operated De-ac lifters have a spring-loaded locking pin actuated by oil pressure. For deactivation, hydraulic pressure dislodges the locking pin, collapsing the top portion of the lifter into the bottom and removing the ability to lift the pushrod. The bottom of each De-Ac lifter rides up and down on the cam lobe but the top does not move the push rod. The valves do not operate and combustion in that cylinder stops. During reactivation, the oil pressure is removed, and the lifter locks at full length. The pushrods, and therefore the valves, operate normally.

The final AFM component is the LOMA. This cast-aluminum assembly is installed in the Vortec 6.0’s V, or valley, in place of a conventional engine block cover. The LOMA holds four solenoids, control wiring and cast-in oil passages. The solenoids are managed by the ECM, and each one controls oil flow to a De-Ac Lifter, activating and de-activating the valves at one cylinder as required for Active Fuel Management.

The Gen IV Vortec 6.0L’s fuel injectors are identical for all cylinders; those feeding the de-activated cylinders are simply shut down electrically by the ECM during de-activation. When the cylinders are deactivated, the engine effectively operates as a V4. AFM operation is load based, as measured by the ECM using dozens of inputs, overlain with the driver’s demand for power as measured by throttle application. AFM’s response time is measured in milliseconds. Operation is always transparent to the driver. The engine returns to V-8 mode the instant the controller determines that acceleration or load requires additional power.

The benefits are substantial. Active Fuel Management does not effect exhaust emissions, and it reduces overall emissions to the extent that less fuel is used. Further, the savings reflected in EPA numbers may not account for AFM’s full impact. Owners who primarily travel long distances at steady speeds will see further fuel-economy improvements.
Old 03-17-2009, 02:25 PM   #6
Registered User
 
OUTLAW525YUP's Avatar
 
Age: 31
Join Date: May 2007
Posts: 84
Location: Red Deer Alberta CANADA!
User is: OffLine
Re: Vvt And Afm

So it is being used togeather. "Finally, cam-phasing helps maximize the fuel-saving benefits of Active Fuel Management technology (below). The cam phaser can adjust valve-timing for maximum torque when the Vortec 6.0L is operating as a V4, keeping the engine in this fuel-saving mode as long as possible" this would be great even I had to stick with the stock cam 403hp in half is still 200hp and that is far more than the old iron duke that was in had and technically it should get great milage.
Old 03-17-2009, 02:26 PM   #7
Need LSx swap.....
 
Kampz69's Avatar

 
Age: 36
Join Date: Feb 2002
Posts: 4,290
Location: SW Chicago burbs
User is: OffLine
Re: Vvt And Afm

good info there
Old 03-17-2009, 03:08 PM   #8
S-series Member
 
lilsonoma's Avatar
 
Join Date: Oct 2007
Posts: 532
Location:
User is: OffLine
Re: Vvt And Afm

With the AFM oil pressure requirements, the new AFM motors get a high volume oil pump. Higher volumes of oil sent through the same oil cavities also means higher pressure so for those of you running 0W oils like I do, it's a decent addition to any rebuild.

Just my .02.
Old 03-17-2009, 07:17 PM   #9
Registered User
 
OUTLAW525YUP's Avatar
 
Age: 31
Join Date: May 2007
Posts: 84
Location: Red Deer Alberta CANADA!
User is: OffLine
Re: Vvt And Afm

lilsonoma where did you get that article. I would like to read up more as I don't know what 6.0 liter they are refering to, and what vehcile it is in.
Old 03-18-2009, 02:48 AM   #10
Registered User
 
Age: 28
Join Date: Oct 2005
Posts: 103
Location:
User is: OffLine
Re: Vvt And Afm

I've taken apart a 6.2 (L92) with both AFM and VVT so some do from factory with that setup. All of the newer engine blocks come with the cast oil passages needed for AFM, so if u swapped the valley cover and lifters you can have your active fuel management. I'm not positive, but I believe you can also just swap the cam, front cover, phaser mechanism, and engine computer to get the vvt. Hopefully somebody else will chime in on swapping over.

All in all some pretty cool technology, and what I typed was just some food for thought. cheers, Jess
Sponsored Links
Advertisement
 

Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the S-10 Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.
User Name:
If you do not want to register, fill this field only and the name will be used as user name for your post.
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid email address.
Email Address:

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.



Thread Tools

Posting Rules
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On



All times are GMT -4. The time now is 11:50 AM.

Powered by vBulletin® Copyright ©2000 - 2011, Jelsoft Enterprises Ltd. SEO by vBSEO 3.2.0
SEO by vBSEO
vBulletin Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.