A couple of months back, we reported that Honda had filed a patent for its next generation variable valve timing and lift control system: appropriately named "Advanced VTEC." At the time, the only information available was the results of this new technology, specifically that it would boost fuel economy, increase performance and spew less emissions into the atmosphere – simply an evolution of their current system.
Paul Tan was able to procure the patent itself and has published the filing on his website, paultan.org (or you can view it here through the U.S. Patent Office).
The short and sweet version involves the employment of a small cylinder encompassing the camshaft that is connected to the rocker shaft. As the drum rotates the rocker adjusts the valve lift and timing. There are several images and a statement of claims posted, which are well worth a look-see if you've got your engineering hat on.
[Source: U.S. Patent Office via PaulTan.org]
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Reader Comments (Page 1 of 1)
David @ Apr 17th 2007 9:43AM
If you're serious about driving, you can match performance with the same hp. Torque just allows for lazier driving. For most people (who provide the bulk of the sales) looking for more economical 4-bangers, this will be a great addition by providing added power (not necessarily in the form of torque) *and* high efficiency.
However, from an even more technical standpoint, this is going to make the engine even *more* expensive by at least doubling the number of moving parts involved in actuating the cams. It definitely has the potential of making cars like the Civic Si even more expensive, depending on how well Honda can keep its mfg costs down.
bob @ Apr 17th 2007 9:59AM
Honda has never added much torque to their engines. They don't cuz that would lower MPG.
George Stewart @ Apr 17th 2007 10:09AM
http://www.revsearch.com/dynamometer/torque_vs_horsepower.html
so that you ignorant (not stupid) blokes can see where torque affects horsepower and mpg.
Now can we have an intelligent discussion from all, not just a few?
Bcknkd @ Apr 17th 2007 10:28AM
Why is everyone so insecure?
The subsequent diatribe from both sides is embarrassing.
sydbot @ Apr 17th 2007 10:33AM
How about we talk about the implications of this technology. Shouldn't a variable lift system, tuned towards increasing efficiency and lowering emissions at lower RPM, be able to create a virtual Atkinson-cycle engine? Personally, I think this is the real jewel of this technology.
HoldenC @ Apr 17th 2007 11:09AM
While I'm not a HUGE fan of Honda/Acura, I do admire their commitment to pushing the leading edge in terms of engineering (particularly engine-related) expertise. This company is "quirky" to say the least, adamantly sticking to their guns about staying independent (even though they're "relatively" small in today's terms), trying to focus on efficiency (one of the highest MPG fleets), and basically being a "techy" type of a company with engineers calling a lot of the shots (for better or for worse). From an overall standpoint, an overwhelming majority of the Honda/Acura owners I've known over the years really LOVE their vehicles; which says a lot; although their "quirkiness" seems to limit how fast they can grow versus Big Toyota.
Myself, I would prefer a little more low/mid-range grunt, and somewhat more distinctive (and attractive IMHO) styling inside & out. From what I hear Honda is starting to understand this also. As a carfan, I think it will be interesting to see where this company goes next.
ssgtakeo @ Apr 17th 2007 12:08PM
I think it is a matter of preference, I don't care how better efficiency combined with power is achieved, I just care that technology from all players involved continues to improve.
REM83 you cannot compare a Corvette and an Accord. Yes the Corvette is a V8, and yes it is AMAZING that it gets such good milage while still being able to perform at the supercar level. However you can get away with things on a sports car that would never work in a typical family car. Once you add the rear seats, safety equipment and amenities that you'd find in an Accord in a Corvette, it ceases to be a Corvette.
You can't compare the two, they do completely different jobs.
Matt @ Apr 17th 2007 12:29PM
21:
"You can't compare the two, they do completely different jobs."
I do believe he was making it a point to compare the engines. And for a reason. ;)
Ryan @ Apr 17th 2007 12:44PM
HP is directly related to Torque and engine RPM.
You can not produce more HP without increasing torque and/or RPM.
A formula 1 car is limited by the rules to the displacement of the engine. For a given displacement only so much can be done to increase torque, so they increase RPM close to 20,000 rpm.
These engines suck down gas and do not last for very many miles or hrs.
A tractor is limited as well a field can not be plowed at 200 mph so the way to do more work in less time is to plow a wider path each pass.
These engines have to last for many hours, miles, years and operate on non-taxed off-road diesel
They turn very slowly by comparison 1200, 1800, 2000 RPM. They produce massive amounts of torque.
The operators are very concerned about fuel economy.
Both tractors and race cars are powerful, high torque at low rpm vs. low torque at very high rpm.
A camshaft is a compromise.
Design it for low end torque and high RPM power suffers, design it for high RPM and it will barely idle.
Variable cam lift and phase systems from GM, Honda, BMW, etc all attempt to do the same thing.
Make more torque (which translates to HP) throughout the operating range of the engine.
If you are BMW you brag about how it makes your engine more powerful (which it does) if you are Honda you brag about lowering emissions and improving MPG which is also true.
If you are GM, it is just as true that it improves power, lowers emissions and improves MPG. But nobody seems to talk about that because it is cool to bash domestic manufactures.
"Once you add the rear seats, safety equipment and amenities that you'd find in an Accord in a Corvette, it ceases to be a Corvette."
#21
Yes, then it becomes an CTS-V
6 liter V8 400 hp vs 3 liter V6 244 hp
24 MPG hwy vs 30
Yes, they do different jobs and neither can do the job the other does as well it self, that does not make either a bad vehicle, just that different.
MikeW @ Apr 17th 2007 12:48PM
Honda intentionally left of the variable resonance on the Accord V6 J30A4 in all applications except the stick shift models. The accord hybrid J30A5 has it.
Part of the problem is the horrible interface with the automatic transmission. P R N D5 D4 D3 with a button on the console to lock out first gear would be correct for the United States. Honda has a useless P R N D5 D3 2 1.
The variable lift will allow better fuel atomization at part load, also isn't the throttle programmed to be at 90 degrees [to be used in event of failure]
Nissan passed honda, who is the maverick now Honda?
Aki @ Apr 17th 2007 1:04PM
It's not just Ugly Truth, you'd need to ban Mike, Aaron, and all the others who turn *any* Big 2.5/Japanese automaker story into a racially-charged spat-fest. The utter lack of IP banning only exacerbates this issue.
As for a-vtec (what i'm guessing it'd be called), it sounds fancy but we'd really have to see it in action. Nice to see that it doesn't require cam profiles anymore, though.
rem83 @ Apr 17th 2007 1:10PM
Ok, there's a difference between deleting comments with offensive content and comments with argumentative comments. I think you guys are going a little crazy here.
Damon Lavrinc @ Apr 17th 2007 1:14PM
To all - We are doing our best to police comments and fend off much of the B.S. that inhabitates this forum. Some of us are better than others and I try to keep tabs on what you guys are saying throughout the day. That said, I'm out on the West Coast and don't start checking e-mail until later in the morning, so in cases like this, it runs rampant until I get online.
As for this space, my apologies to anyone who had a comment deleted that contained some honest debate. Anything that pertained to the matter was nixed. It's just how the system works -- for now. But that will all change soon enough.
geo.stewart @ Apr 17th 2007 1:29PM
No apologies necessary Damon.
That others abuse the privilege offered here does not reflect on Autoblog but on the abusers. I for one appreciate the updates ya'll (yeah, I'm in the South) post and the platform to comment when I take a car-break (instead of a smoke break)./
Avinash machado @ Apr 17th 2007 1:45PM
Thanks Damon.
mcr @ Apr 17th 2007 1:55PM
I could see reasons behind deleting the off color post, but why would the mods delete a post pointing out the fact that this "news" broke over 2 months ago?
This was published on Feb 9, 2007:
http://www.vtec.net/news/news-item?news_item_id=659664
Don @ Apr 17th 2007 5:00PM
Excellent! More efficiency...the same amount of no torque!
RickDom @ May 24th 2007 8:50AM
I feel the Advanced VTEC kicking in!