Will Camshafts Soon Become Extinct?
Originally Posted by 01WS6er
The TB is only there for failsafe. Once engine cranks the TB opens completely. Try a search its out there. Think about a 380HP 750 that weights about 4500 lbs gets 26-28 MPG on the highway, now that is cool.
Just a little more food for thought.
Just a little more food for thought.
That is actually one of the most attractive things about electronically operated valves. With the TB open you can run down the road with a intake at a higher pressure.
You can also do things like have more square valve events. You can also close the intake valve extremely prematurely at part throttle so the rest of the intake stroke acts like a spring, loading up energy that you can for the most part reclaim on compression.
Also at part throttle you can open exhaust very close to BDC (while still closing at BDCexhaust). what would that do is make better use of the power stroke at low throttle.
I've also read that 42 volt systems could shed a significant amount of wieght in wiring. The problem is its edging on what can be considered dangerous.
Thread Starter
TECH Fanatic
Joined: May 2005
Posts: 1,135
Likes: 1
From: The 'Burgh, PA
Great insight Alvin - the impact on the TB was not immediately obvious to me until I heard a few of you bring it up. Things really get interesting when you start talking about leaving the TB open while cruising down the road at low RPM's. The computer would control even more aspects of the engine, and the valves would no longer be slaves to a mechanical camshaft profile that cannot change. Emissions could also be greatly improved with less mechanical parts / systems.
Thanks,
Just think about it. ON your intake stroke your doing alot of work by moving the piston down with such a heavy vaccum on it. With electronically opened valves you can start your intake stroke, open your valve really quick while your expansion (volume) rate is high near TDC.. get your little shot of air and then close again. Since all the cylinders aren't fighting for a small piece of air in the intake, the manifold can remain at ATM.
You would be controlling cylinder filling with valve events instead of putting a HUGE restriction on the intake.. that being the throttle body.
Just think about it. ON your intake stroke your doing alot of work by moving the piston down with such a heavy vaccum on it. With electronically opened valves you can start your intake stroke, open your valve really quick while your expansion (volume) rate is high near TDC.. get your little shot of air and then close again. Since all the cylinders aren't fighting for a small piece of air in the intake, the manifold can remain at ATM.
You would be controlling cylinder filling with valve events instead of putting a HUGE restriction on the intake.. that being the throttle body.
Originally Posted by gametech
I wasn't referring to the valve actuators as switches. I was referring to switches and relays in the rest of the vehicle. Ignition, window, and door switches, for example, are all still part of the total vehicle package that would be affected by higher DC voltage. Higher voltage does have the side benefit of allowing for smaller electrical wires, saving weight and money.
http://www.isqe.com/
Correct about the voltage increase decreases the current needed to be moved so the wiring is smaller.
Originally Posted by spy2520
i think i heard that 48v was the original plan, and something about a possible safety issue where 42v is already going to shock you if you touch both terminals like you can easily do on a 12v battery, 48v was just enough of an increase that it would actually shock the **** out of you just enough that even with rubber gloves you'd feel it and it would hurt...thats all hearsay though...
I don't see it as being a real safty issue.
This has been discussed for years. I remember 1st reading about the change that "Needs" to be made to a 48V system back in 1995/96. Car Stereo people have been paying attention to this for years since the ability of the system is roughly 3-4x what's out there now.
Originally Posted by 2002_Z28_Six_Speed
Don't diesels [military] get away from that by putting somethings in circuit with only one battery and somethings in circuit with both batteries?? That would be a solution for civi cars.
48 volts is far from dangerous. You can put one hand on the - side and one on the + side of 48 volts and it aint gonna hurt you one bit. Ive been on about 70 VDC and its a small sensation, nothing thats going to hurt ya.
LS1 Tech Stories
The Best V8 Stories One Small Block at Time
Gas Monkey Built a 6-Wheel Ferrari Testarossa With a Corvette LT4 Engine
Verdad Gallardo
7 Most Reliable High-Performance Engines GM Has Ever Built
Verdad Gallardo
Amazing '71 Camaro Restomod Is Modern Muscle Car Under the Skin
Verdad Gallardo
6 Common C5 Corvette Failures and What's Involved In Repairing Them
Pouria Savadkouei
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph
Verdad Gallardo
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked
Pouria Savadkouei
Top 10 Most Powerful Chevy Trucks Ever Made!
Hennessey's New Supercharged Silverado ZR2 Has 700 HP
Verdad Gallardo
Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes
Verdad Gallardo
48 volt's is barely a tingle. IT won't "Shock" you bad at all. Especially mechanics (dried out skin on their hands). If you want to try it out, go find your door-bell system in your house. That's a 48V DC system. It'll give a tiny shock. Some people like myself with dried out hands barelly feel it at all. For women, it's a tiny shock. (Women by study have lower resistance in their bodies)
Originally Posted by mcamp001
I think most home doorbell/ thermostat systems are 24 volt, at least mine is
Teching In
Joined: Dec 2003
Posts: 31
Likes: 0
Originally Posted by 1CAMWNDR
Her ya go fellas. Check this **** out:
http://www.sturmanindustries.com
http://www.sturmanindustries.com
Yeah, read about something like this a while back.
And on a side note, I played the piano for Penn State's Christmas Party on Christmas Eve (they're in town for Outback Bowl). I got to shake Joe's hand. Pretty cool.
And on a side note, I played the piano for Penn State's Christmas Party on Christmas Eve (they're in town for Outback Bowl). I got to shake Joe's hand. Pretty cool.
Camless engines are inevitable, we just need the kinks ironed out. About 10 years ago I read an article where a researcher used piezo-electric transducers to actuate valves on a single cylinder engine. The piezos have only a tiny stroke so it was rigged up with 20:1 rocker style arms to amplify the motion. The engine ran really well. The big problem was the engine produced about 5 kW while the "valve train" required 15 kW to operate. Power consumption of the camless valve train will take quite a while to improve even after the system is working well. Its not obvious how to efficiently operate a whole valve train electrically without expending a lot of power.
Originally Posted by brad8266
48 volts is far from dangerous. You can put one hand on the - side and one on the + side of 48 volts and it aint gonna hurt you one bit. Ive been on about 70 VDC and its a small sensation, nothing thats going to hurt ya.
Originally Posted by brad8266
um..ok. Have you ever got shocked my an electric oulet at home before?? Its not that bad. Thats 120V, 50 isnt anything compared to that.
120VAC --> 84.85 VDC. That arguement is very misleading and from your reply it does sound like you didn't even give that thought. Don't play off electricity as a toy. AC is a sine wave so that higher voltage is overrated compared to a DC shock or the average voltage of AC over time.
By the way. You can experience low voltage/high current (short like condition) and high voltage/low current (open like condition) in your body from wet skin vs dry skin respectively. Do you honestly believe that it is still 120 Volts by the time it gets to your heart? AHAHAHAHA Ever heard of voltage divider?
Guess not.Measure from body to ground NOT source to ground. IN YOUR BODY. Look up Kichoff's Law for confirmation. Further, look up current controlled circuits. Your certificate only covers a tightly managed power system. Not the world of the possible. And that's "what I know about this electric."
-------------
Unrelated
-------------
I love it when people, mostly on the net, condone common knowledge and rub it off as unneeded intelligence or "book-smarts."
I understand that my revision to this post sounds smart allic, however, that is due to the conditions under which other people treated me despite I was diligent and mature with them at first. Text made small as off-topic.
Last edited by 2002_Z28_Six_Speed; Jan 26, 2007 at 08:39 AM.
Originally Posted by 2002_Z28_Six_Speed
I have a 50 volt induction coil you can try out in that case.
I thought it was the amperage that was most dangerous. At least for 12v/24v/48v dc and 110v/220v ac. Your skin shouldn't allow enough conduction, unless the current burns through the outer flesh.
from http://www.cdc.gov/niosh/elecovrv.html
Estimated Effects of 60 Hz AC Currents
1 mA Barely perceptible
16 mA Maximum current an average man can grasp and "let go"
20 mA Paralysis of respiratory muscles
100 mA Ventricular fibrillation threshold
2 Amps Cardiac standstill and internal organ damage
15/20 Amps Common fuse or breaker opens circuit*
*Contact with 20 milliamps of current can be fatal. As a frame of reference, a common household circuit breaker may be rated at 15, 20, or 30 amps.
1 mA Barely perceptible
16 mA Maximum current an average man can grasp and "let go"
20 mA Paralysis of respiratory muscles
100 mA Ventricular fibrillation threshold
2 Amps Cardiac standstill and internal organ damage
15/20 Amps Common fuse or breaker opens circuit*
*Contact with 20 milliamps of current can be fatal. As a frame of reference, a common household circuit breaker may be rated at 15, 20, or 30 amps.
Staging Lane
Joined: Feb 2005
Posts: 56
Likes: 0
From: Ontario, Canada
Mercedes C-class debuts with this technology as a 2008 model.
http://paultan.org/archives/2005/07/...valve-engines/
http://paultan.org/archives/2005/07/...valve-engines/