Max Engine HP at every RPM?

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sicbeing

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Cribanox
http://auto.howstuffworks.com/camshaft6.htm

Several engine manufacturers are experimenting with systems that would allow infinite variability in valve timing. For example, imagine that each valve had a solenoid on it that could open and close the valve using computer control rather than relying on a camshaft. With this type of system, you would get maximum engine performance at every RPM. Something to look forward to in the future...
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Wow. I love going to this website, it's made me much morew knowledgeable, did anyone of you hear about something like this? I don't see how it's possible to get max power at every rpm, and I read the web page multiple times to try and understand it lol.
 
When they say max performance they don't mean maximum power. When you are doing something like valve timing on an engine its a compromise. If you tune the valve timing to get as much power as possible at 2000rpm, then tune it again at 3000rpm, you will find that different timing works best for each rpm. By doing it fully variable, you can get the ideal timing for each engine speed. Without the variable valve timing you have to make compromises and you end up with an engine that isn't making as much power as it could be.

It's like Honda's VTEC system. You find that one camshaft works well at 2000rpm, but sucks at 8000... and the one that works well at 8000 sucks at 2000. Honda's solution is to put both camshafts in and switch between the two of them. With a fully variable system like they are describing, you'd get rid of those camshafts completely and you can have the computer control exactly when the valves open and close.

...that was not a clear and concise answer at all :)
 
^ What he said.

BMW is one of the companies working on this technology. One problem to overcome is the amount of electrical power required to operate the solenoids, which is considerable.

I imagine another problem is to make them reliable enough to run for years and years. You don't want one to poop out on you in an interference design, as many many cars are nowadays.


M
 
If I remember correctly, BMW and Renault did electromagnetic valves on their F1 engine a couple seasons ago. Not for max efficiency or power band reasons though. They did it because normal valve springs can't keep up with 20,000rpms. I think they use hydraulics now, but either way, there is no camshaft.

I don't see this as being very far from showing up in high end cars. If you can electrically, magnetically, or hydraulically control the valves without having to mess with cam shafts and valve springs, thats a great thing. More control just opens sooo many doors for tuning and efficiency. Should be sweet.

Hilg
 
I have the F12000 book by Peter Wright... it's absolutely nuts some of the tuning they do. Maybe I can tell yall about it after this history test :nervous: that I'm 'studying' for ;)
 
Bah. I'll stick with Pushrods. *pouts in corner*

:dopey:

That's crazy... So would a "VTEC" Smallblock be possible?
 
The actual design of VTEC is that there are 3 lobes on each cam for each set of valves. If you were to look at an engine like the very commen B16A, its a 1.6 liter dohc vtec engine. Each cam has two lobes that open the valves for the lower rpm range and at higher rpm lobe is locked into place by a pin activated by oil pressure. The smaller lobes are designed to be just right for the lower rpm and the bigger profile is for the higher rpm power. This is how Honda got 170hp out of a 1595cc engine is street tune.

We could also look at a SOHC D16Z6. This engine, being a sohc engine, does not have room for vtec to be used on both the intake and exhaust vavles. so, it only has vtec for the intake valves but works the same way.

Now we could also look at a SOHC D15B (jdm.) It is also a sohc engine and has three lobes for each set of valves but they are all different unlike normal vtec engines. There is a very small profile that works under 2000rpm by only being big enough to prevent fuel pudling. there is a normal profile for 2000-4600rpm and then the vtec profile that operates like a normal sohc vtec engine. this system is called the 3 stage vtec system.

There is also a system called VTEC-E which works the same way as the stage vtec but there are only two profiles. there is no high rom profile and this system is used for ultra high fuel economy.


that may or may not make any sense to you all.
 
I wasnt going to make such a long reply but it just came out. I was just going to explain it a little to bring some more understanding to this topic.
 
In addition to working on solenoid-actuated VVT, as ///M-Spec mentioned, BMW is also working on a new design of mechanical VVT that is almost as variable as with solenoids, but made with more familiar technology:

http://www.mr2sc.com/websites/articles/VVTI-BMW Mechanical VVT.jpg

MR2SC.com
BMW has actually designed a mechanical system that still uses conventionalcam lobes, but is still able to vary lift and timing by moving the fulcrum point of the rocker arm. The system is incrediblydifficult to visualize (I still don't get it.) but it could offer most of the advantages of electrically actuated valves without delving so far into unexplored technologies.
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Taurine
.... and where did that come from? :odd:
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THE ED3's post is a reply to retsmah's first post in this thread, and a clarification of how a certain VVT system works in a thread where the subject is VVT. Makes sense to me. :)

Taurine
Wouldn't solenoids take up more room then what a camshaft would occupy?
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Depends on how much energy is needed.

Speaking of VVT and HowStuffWorks.com, Ferrari's VVT is pretty neat. It uses a 3-dimensional lobe profile and simply shifts the cams:

camshaftferrari8pb.gif
 
THE ED3
I wasnt going to make such a long reply but it just came out. I was just going to explain it a little to bring some more understanding to this topic.
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Thats cool, but VTEC isnt the topic :)


The solenoid valve system has been in the works or talked about for quite a few years now.

Btw anyone want some detailed technical info on different VVT type systems go here
http://www.autozine.org/technical_school/engine/vvt_1.htm
 
boy it would suck to have an electrical problem on that car though. Oops! There goes the engine.


haha nice avatar retsmah
 
sicbeing
Well, I understood what I posted... somewhat, but now I'm 100% confused! lol
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Maximum HP (what you said):
maxhp2be.jpg


Maximum Performance (what solenoid valves would do):
maxperformance7hn.jpg


VVT systems vary valve timing in order to increase performance in different RPM ranges. The flash animation and information at http://auto.howstuffworks.com/camshaft2.htm provide a good explanation of how and why this is done.
 
JNasty4G63
If I remember correctly, BMW and Renault did electromagnetic valves on their F1 engine a couple seasons ago. Not for max efficiency or power band reasons though. They did it because normal valve springs can't keep up with 20,000rpms. I think they use hydraulics now, but either way, there is no camshaft.
Click to expand...

There was some talk of renault doing electromagnetic valves that i remember, but they never made it happen. I was just talking about one of our engine guys about this yesterday, apparently there are some experimental engines out there using electric soleniod operated valves. There's some neat stuff they can do with them, like they can eliminate the throttle, instead of shutting a throttle you just dont open the valves as much. Not ready for production cars yet though.

Modern F1 cars actually do have camshafts, the hydaulics are used to replace your standard valve spring. So the hydraulic just closes the valve in the same way that a valve spring closes a valve. Except that as you said valve springs break at crazy high rpms, hydraulics dont :)
 
retsmah
There's some neat stuff they can do with them, like they can eliminate the throttle, instead of shutting a throttle you just dont open the valves as much. Not ready for production cars yet though.
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BMW have already made throttleless engines with their Valvetronic technology without using electromagnetic valves but instead with a fairly complex mechanical system.

Here is an explaination and pictures on how they did it, easier than me trying to explain (scroll down near the bottom).

http://www.autozine.org/technical_school/engine/petrol2.htm
 
retsmah
Modern F1 cars actually do have camshafts, the hydaulics are used to replace your standard valve spring. So the hydraulic just closes the valve in the same way that a valve spring closes a valve. Except that as you said valve springs break at crazy high rpms, hydraulics dont :)
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Good info, I didn't know that was how they did it. I knew there were some hydraulics used, just not to the extent they are. Weird, oh well.

Hilg
 
VIPERGTSR01
BMW have already made throttleless engines with their Valvetronic technology without using electromagnetic valves but instead with a fairly complex mechanical system.
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That is really cool. The electric systems may end up being better, but they probably wont match the coolness of all the gears and levers and cams of the mechanical systems :)
 
///M-Spec
^ What he said.

BMW is one of the companies working on this technology. One problem to overcome is the amount of electrical power required to operate the solenoids, which is considerable.


M
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Bigger battery? Or research into batteries for them to hold more charge longer.
 
You need a bigger alternator, if you are pulling more power than your alternator can put out then you are going to kill your battery. The battery is really only there for starting the car and running electronics when the car is off.
 
retsmah
That is really cool. The electric systems may end up being better, but they probably wont match the coolness of all the gears and levers and cams of the mechanical systems :)
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This calls to mind watches, for some odd reason. We've had full on electrical watches for decades, but technophiles still prefer mechanical ones. :indiff:

And even when they do buy a quartz watch, they buy one with hands instead of the more accurate and readable digital display. (guilty, your honor. :lol: )
 
LeadSlead#2
when this first comes out, it's going to break like crazy
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That's why manufacturers test things, so that they won't break by the time they're released.

@VIPERGTSR01: Whoa, I actually learned something new about BMW today. :dunce: It's been a while since I've done that. :lol: :) I've always wondered what Valvetronic was...
 

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