Variable Valve Timing for 6.2L
12-10-2005, 02:26 AM
#1
Variable Valve Timing for 6.2L Am I the only one excited that the new 6.2L will have variable valve timing? I know you would need a newer PCM, but VVT could allow a larger aftermarket cam to be much more friendly down low in the RPM range.
12-10-2005, 05:15 PM
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im also very excited but i wish this was around a couple of years ago. all i ever hear when i argue with ricers is how toyota has VVT-i already and has for a while. and they bash how american cars are way behind... which they are but still it pisses me off ha ha.
12-10-2005, 08:16 PM
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Originally Posted by Syxx613
im also very excited but i wish this was around a couple of years ago. all i ever hear when i argue with ricers is how toyota has VVT-i already and has for a while. and they bash how american cars are way behind... which they are but still it pisses me off ha ha.
12-10-2005, 09:51 PM
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the vvtl is pretty cool actually. we had a celica gts with the vvtl-i and a 6speed, when that thing was going up the revs and passed 6grand the whole sound of the motor changed and it started rippin and pulls to 8200rpm, then when you shift it lands you right at the beginning of the powerband around 5900-6100 in the 1-2 and 2-3 shifts. if gm can work that nicely into a respectable car, it will be insane.
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12-10-2005, 10:07 PM
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the new issue of hot rod has a small write up about it.according to the article,it's able to maintain 90% of it's peak TQ (415 ft. lbs.) from 2300-5600 rpm.pretty impressive.i wouldn't say american cars are that far behind the imports.it's actually impressive that GM is able to keep a pushrod V8 engine viable that still meet emissions and economy in todays world of overhead cam 4 bangers.
Last edited by 66deuce; 12-11-2005 at 06:31 AM.
12-10-2005, 10:10 PM
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Originally Posted by Grimes
Am I the only one excited that the new 6.2L will have variable valve timing? I know you would need a newer PCM, but VVT could allow a larger aftermarket cam to be much more friendly down low in the RPM range.
12-10-2005, 10:33 PM
#10
Originally Posted by 66deuce
with LS7 style heads,imagine the power you could get with a good port job and a bigger cam.maybe we can finally have our cake and eat it too.
like having a TRex idle like a stocker? lol, maybe that's pushing it a bit far....
12-15-2005, 06:05 PM
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Originally Posted by 66deuce
i wouldn't say american cars are that far behind the imports.it's actually impressive that GM is able to keep a pushrod V8 engine viable that still meet emissions and economy in todays world of overhead cam 4 bangers.
12-17-2005, 11:33 PM
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Yea well the one thing that hasnt been said in this thread yet is that its still OHV, The very 1st OHV VVT car is the G6, I drove a 3.9 2 valveV6 6 speed with the vvt and ( its FF so it doesnt feel fun ) but the car doesnt ever feel like its out of the Max power range. It moves pretty damn fast for a "240 hp" car, 3400lb car. 6.* second 0-60, mid 15 second ¼ mile and gets like 28 mpg.
I think a perfomance based LS VVT car would be aweome, imagine the MPG possiblites =)
I think a perfomance based LS VVT car would be aweome, imagine the MPG possiblites =)
12-19-2005, 01:06 AM
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Originally Posted by BuffJoeyD
Yea well the one thing that hasnt been said in this thread yet is that its still OHV,
12-19-2005, 03:40 AM
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There are DOHC vehicles with lower CG's... Most of them are inline.. non V engines..
Its not so much the height on a V8 quad cam but the width of the package..
Total engine weight with a belt driven 4 cam v8 and doing things like hollow core cams is'nt much different.. There are some components like push rods that are gone and others alot simpler and lighter.. rockers. lifters for cam followers and HLA's.
That being said if OHV's did'nt have their own advantages they would'nt still exist.
There will likely be ways to update older LSx engines with this technology..
Its not so much the height on a V8 quad cam but the width of the package..
Total engine weight with a belt driven 4 cam v8 and doing things like hollow core cams is'nt much different.. There are some components like push rods that are gone and others alot simpler and lighter.. rockers. lifters for cam followers and HLA's.
That being said if OHV's did'nt have their own advantages they would'nt still exist.
There will likely be ways to update older LSx engines with this technology..
12-19-2005, 03:59 AM
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Originally Posted by Grimes
Am I the only one excited that the new 6.2L will have variable valve timing? I know you would need a newer PCM, but VVT could allow a larger aftermarket cam to be much more friendly down low in the RPM range.
You would probably run a little smaller cam than a non VVT for the same top end as the high rpm setting of the VVT would need to be taken into account in spec-ing the cam..
I am guessing too that LSA's run will be tighter as well.
I wonder if Kurt at W2W knows how many degrees of actuation the system has?
Last edited by V8_DSM_V8again; 12-19-2005 at 04:07 AM.
12-19-2005, 07:32 AM
#17
Originally Posted by V8_DSM_V8again
Basically its just variable cam advance and retard...
You would probably run a little smaller cam than a non VVT for the same top end as the high rpm setting of the VVT would need to be taken into account in spec-ing the cam..
I am guessing too that LSA's run will be tighter as well.
I wonder if Kurt at W2W knows how many degrees of actuation the system has?
You would probably run a little smaller cam than a non VVT for the same top end as the high rpm setting of the VVT would need to be taken into account in spec-ing the cam..
I am guessing too that LSA's run will be tighter as well.
I wonder if Kurt at W2W knows how many degrees of actuation the system has?
Small-Block Glory
GM's full-size 2007 SUVs will get power from a range of V8s similar to those currently available: a 4.8-liter generating 290 horsepower, several 5.3s, and 6.0s producing up to 355 horsepower. The high-power news is a 6.2-liter variant for the Escalade and luxury Yukon Denali, with an anticipated 400 horsepower.
Most of the engines have aluminum blocks; all share the Gen IV architecture introduced in the 2005 Corvette, with engineering tailored to the demands of a truck. The 6.0 and 6.2 will deliver a significant increase in power compared to the previous premium engines, thanks to high-flow cylinder heads developed for the LS7 V8 in the Z06 Corvette. Both also feature something few might have imagined a few years ago: variable valve timing in a cam-in-block engine.
GM's pushrod VVT uses a spline-type phaser to turn the camshaft relative to its drive sprocket. Given the single cam, intake and exhaust valve timing change at the same rate with a fixed relationship, but GM says the VVT helps improve fuel economy, reduce emissions and optimize the balance of low-end torque and high-rpm horsepower.
Given the trend in gas prices, and recent public opinion polls suggesting American drivers are more concerned with fuel economy, GM is particularly sensitive to the issue. It's response? Its full-size SUVs are already the most fuel-efficient available, and the 2007 models increase the edge. The company expects all variants to exceed 20 mpg in the EPA's combined mileage rating.
Further, GM's PR staff is trying its best to focus on fuel-saving technologies built into its next-generation big SUVS. The premium models get new six-speed automatic transmissions. Most still get four-speeds, though the company says the six-speeds will be installed across the board as its capacity to build them increases.
Advertising will focus on GM's Displacement on Demand technology. The 5.3 and 6.0 V8s — the most popular choices — are equipped with the system, which deactivates four cylinders under light-load conditions to reduce fuel consumption. All 5.3s can run on E85 ethanol, which theoretically can reduce gasoline consumption 85 percent. And the company promises new dual-mode hybrid technology in calendar 2007. The system is being developed jointly with BMW and DaimlerChrysler, and uses small motors in the gearbox rather than larger ones inline with the combustion engine. It will reportedly be much less expensive to build, while delivering a 25-percent improvement in fuel economy.
In any case, the new frame and powertrains in the 2007 models increase towing capacity to 7,200 pounds (two-wheel drive) and 7,700 pounds (four-wheel drive) in short-wheelbase versions, and to a class-leading 9,800 pounds with the long wheelbase.
http://www.edmunds.com/insideline/do...ticleId=107589
GM's full-size 2007 SUVs will get power from a range of V8s similar to those currently available: a 4.8-liter generating 290 horsepower, several 5.3s, and 6.0s producing up to 355 horsepower. The high-power news is a 6.2-liter variant for the Escalade and luxury Yukon Denali, with an anticipated 400 horsepower.
Most of the engines have aluminum blocks; all share the Gen IV architecture introduced in the 2005 Corvette, with engineering tailored to the demands of a truck. The 6.0 and 6.2 will deliver a significant increase in power compared to the previous premium engines, thanks to high-flow cylinder heads developed for the LS7 V8 in the Z06 Corvette. Both also feature something few might have imagined a few years ago: variable valve timing in a cam-in-block engine.
GM's pushrod VVT uses a spline-type phaser to turn the camshaft relative to its drive sprocket. Given the single cam, intake and exhaust valve timing change at the same rate with a fixed relationship, but GM says the VVT helps improve fuel economy, reduce emissions and optimize the balance of low-end torque and high-rpm horsepower.
Given the trend in gas prices, and recent public opinion polls suggesting American drivers are more concerned with fuel economy, GM is particularly sensitive to the issue. It's response? Its full-size SUVs are already the most fuel-efficient available, and the 2007 models increase the edge. The company expects all variants to exceed 20 mpg in the EPA's combined mileage rating.
Further, GM's PR staff is trying its best to focus on fuel-saving technologies built into its next-generation big SUVS. The premium models get new six-speed automatic transmissions. Most still get four-speeds, though the company says the six-speeds will be installed across the board as its capacity to build them increases.
Advertising will focus on GM's Displacement on Demand technology. The 5.3 and 6.0 V8s — the most popular choices — are equipped with the system, which deactivates four cylinders under light-load conditions to reduce fuel consumption. All 5.3s can run on E85 ethanol, which theoretically can reduce gasoline consumption 85 percent. And the company promises new dual-mode hybrid technology in calendar 2007. The system is being developed jointly with BMW and DaimlerChrysler, and uses small motors in the gearbox rather than larger ones inline with the combustion engine. It will reportedly be much less expensive to build, while delivering a 25-percent improvement in fuel economy.
In any case, the new frame and powertrains in the 2007 models increase towing capacity to 7,200 pounds (two-wheel drive) and 7,700 pounds (four-wheel drive) in short-wheelbase versions, and to a class-leading 9,800 pounds with the long wheelbase.
http://www.edmunds.com/insideline/do...ticleId=107589
BTW, I'm sorry I didn't mention in the first post that the engine is still cam in block
Jap CRAP
12-20-2005, 12:39 AM
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Imagine having a powerband that looks like this:
----------------------------------------->
On the subject of variable stuff...what if someday we had variable stall speeds?
Just think, you could have the ultimate engine that could do it all. High mileage and smoothness when you drive, and high power when you race.
----------------------------------------->
On the subject of variable stuff...what if someday we had variable stall speeds?
Just think, you could have the ultimate engine that could do it all. High mileage and smoothness when you drive, and high power when you race.