View Full Version : does this exist?


IamSam
07-04-2011, 04:24 AM
I was just thinking about how to make an engine more efficient and effectively put that power to the ground. Something may already exist, im not sure, but its definitely something Ive been thinking about!

First off the transmission would have to be continuously variable (CVT), so the engine would always be in its power band. Next the engine would have to have some sort of forced induction so it would be more efficient.

I was mainly thinking about the valve train. I know Variable valve timing exists, but what about eliminating the camshaft(s) all together? Why cant you just have all of the valves controlled directly by solenoids? It doesn't seem that far-fetched to me. Has this been thought of before? Any reason it wouldnt work? - V

O.N.
07-04-2011, 04:42 AM
i think some F1 teams use air actuated valves off an air compressor this give you a million different durations lift everything for you to play with you can get some camshafts that have good bottom end good mid range bad top end.
and cams that have good mid good top and bad bottom, with air valves it is good all over.

Old Geezer
07-04-2011, 04:32 PM
http://scarbsf1.com/valves.html

Springs are replaced w/ the air system, not the cams...

O.N.
07-05-2011, 08:39 AM
well how cool would my idea be...lol 1000 different variations of life duration everything...lol
10 million camshaft designs in 1...lol

Ethan[ws6]
07-05-2011, 11:00 AM
BMW uses solenoids in some engines to control valve events but they are only capable of doing like 5k RPM. Some companies like Toyota control intake valves by means other than camshaft to control compression and improve efficiency at different times.

farmington
07-19-2011, 08:43 PM
Lots of interesting things going on behind closed doors in the auto industry right now. Yes, camless engines. cams with two lobes per valve. Of course the direct injection.

1SLwLS1
07-22-2011, 02:03 PM
;15116609']BMW uses solenoids in some engines to control valve events but they are only capable of doing like 5k RPM. Some companies like Toyota control intake valves by means other than camshaft to control compression and improve efficiency at different times.

That's damn impressive that they're good to 5K. I looked into this a while back and finding a solenoid capable of handling ~54 Hz @ 6500 RPM that can also handle the environment is a tall order.

COPO9560
07-22-2011, 10:41 PM
If you want to see something different in valve train, look at Ducati's Desmo system - no valve springs.

A solenoid might have issues moving valves quick enough without overheating at highe engine speeds. One cannot instantly open or close a valve that has mass - you have laws of physics that are hard to get around. Split lobe cams that allow changes in duration are an interesting concept, I believe Porsche tried this a few years back.

YodiBrodi
09-05-2011, 01:42 PM
[/QUOTE] Split lobe cams that allow changes in duration are an interesting concept, I believe Porsche tried this a few years back.[/QUOTE]

sounds like honda's vtec to me, a more aggressive lobe design that's actuated over a certain RPM for a broader powerband. and we all know that's been around for over 20 years.

then BMW has a system that can actually change valve lift throughout the RPM range instead of like the vtec on/off switch but duration remains relatively the same, i believe

jimmyducati
09-05-2011, 03:30 PM
ducati's desmo valve system is nice, although a bit finicky on adjustments and can cost alot of money if its not set up correctly. openers, closers, shims and cams cost ALOT of money, even for a bike with 8 valves.

got milk??
09-05-2011, 09:32 PM
This may be something your interested in!

http://www.launchpnt.com/portfolio/transportation/magnetically-actuated-engine-valve/

chuntington101
09-06-2011, 07:44 AM
I was just thinking about how to make an engine more efficient and effectively put that power to the ground. Something may already exist, im not sure, but its definitely something Ive been thinking about!

First off the transmission would have to be continuously variable (CVT), so the engine would always be in its power band. Next the engine would have to have some sort of forced induction so it would be more efficient.

I was mainly thinking about the valve train. I know Variable valve timing exists, but what about eliminating the camshaft(s) all together? Why cant you just have all of the valves controlled directly by solenoids? It doesn't seem that far-fetched to me. Has this been thought of before? Any reason it wouldnt work? - V


I think it was the Williams F1 team that used a form of CVT transmition in F1, right before it was band for being TOO effective! So it dose work. lol Basically the idea is you can hold the engine at a constant rpm to devilver the most power. In a really world senario as you accelerate the engine would automaticely blip to peak power rpm and you would accelerate away. Then once the required spped was reached the engines RPM would fall away but maintain a contact road speed. Big engines would not be needed as much smaller unit could provide the power required ofor short periods during acceleration. Also oyu wouldn't need the broad exspance of torque as the engine would hold a fixed RPM while accelerating. Plus the engines could be designed to work most effectively at fixed engine speeds (a bit like aero piston engines).

F1 has and still dose use pneumatic valve springs. This effectilve means you can run MUCH harder acceleration on the cams than you can with a spring. role on greater cylinder filling and thus more power.

Lotus has done a lot of testing on electronic valves and variable comp. ratio engines. nothing really come to life on these though.

CHris.

GNIUS
09-19-2011, 11:14 PM
Siemens has also been working on some solenoids for doing this. The hard part is initial start up timing and long term reliability. There is a lot of heat in a small space and alot of repetitive wear surfaces.

roninsonic
09-20-2011, 12:03 PM
there's an Alfa Romeo production car with a primitive version of this... Google the Alfa Romeo MiTo Multiair.


Camless has been sort a holy grail for a while... I mean, PERFECT valve lift and duration for EVERY combustion event is CRAZY... The torque curve on an LS1, for example, would look INSANE. And then you get into the tuning aspects of it. If the system was run off of tables in the PCM, you could do all sorts of crazy things like change lift and duration for load and throttle percentage, as well as RPM. With a properly engineered and tuned setup, you could have a street/strip MONSTER that could get 35-40mpg on the ride home. All with no idling problems.

t/a98
09-20-2011, 01:22 PM
There is a continuously variable desmodromic design too. I don't remember the exact name but the throttle cable went to the valvetrain and it has no throttle body. It changes duration and lift in accordance to throttle input.

1CAMWNDR
09-21-2011, 11:12 AM
Sturman Industries is a real heavy hitter in the camless engine world. Their Digital Hydraulic valve actuation looks promising:


http://www.sturmanindustries.com/main/hydraulicValveActuation.htm

chuntington101
09-21-2011, 01:42 PM
There is a continuously variable desmodromic design too. I don't remember the exact name but the throttle cable went to the valvetrain and it has no throttle body. It changes duration and lift in accordance to throttle input.

Isn't something similar fitted to some BMW engines?.....

cutlass_455
09-29-2011, 08:53 PM
Or you could get rid of the poppet valve altogether and use this...

http://www.coatesengine.com/

This is awesome because you dont have a mass going up and down. Also the valve doesnt protrude into the chamber so PTV clearance isnt an issue.

chuntington101
09-30-2011, 08:02 AM
Or you could get rid of the poppet valve altogether and use this...

http://www.coatesengine.com/

This is awesome because you dont have a mass going up and down. Also the valve doesnt protrude into the chamber so PTV clearance isnt an issue.

First off this idea has been around for a long time. UI perosnally haven't really seen anything come of it. Its a good idea, but i bet its a B!TCH toseal the thing under full working load!

WeaponX_Perf
09-30-2011, 05:27 PM
Most Nissan Vehicles have a CVT instead of a 5 or 6 speed auto these days. My best friend worked at Nissan HQ and I got to try out the prototype a few years back. Pretty wild watching the rpms stay pegged at 6K.

http://www.nissan-global.com/EN/TECHNOLOGY/OVERVIEW/cvt.html

nicentech
09-30-2011, 06:03 PM
I'm a nissan tech and the cvt is awesome. It's been out since 2003 and has really worked well. Its main drive is a wide steel belt that runs between two sets of pulleys, rather cool to see. They however do not make and rwd cvt transmissions, which is a buzz kill for sure! Check out the newer nissan and infinity 3.7L v-6 vq37vhr it has vvel which is awesome and had huge performance gains. It still has the conventional cam timing that's cam sprocket controlled but also has a motor on the cam that's like a varraible vtec. Check it out rather innovative

cutlass_455
09-30-2011, 11:06 PM
First off this idea has been around for a long time. UI perosnally haven't really seen anything come of it. Its a good idea, but i bet its a B!TCH toseal the thing under full working load!

First off, I never said it was a new idea. I heard of this about 15 years ago, as Im sure other have too, or probably longer.

chuntington101
10-02-2011, 05:54 AM
First off, I never said it was a new idea. I heard of this about 15 years ago, as Im sure other have too, or probably longer.

Didn't mean to come across as an *ss mate. sorry. :)

have you seen sleave valves? They where used heavily in British WW2 aero engines in the later stages of the war. supposed to give significant performance advantages of poppet valves (although they had aot of problems sealing poppet valves back in the 1940's).

Chris.

cutlass_455
10-02-2011, 03:25 PM
Its alright Chris, no offense taken.

No, I havent heard of them valves, have to look them up.

71novaguy
10-02-2011, 06:02 PM
back in the day, fighter planes used a dual lobe cam shaft that the pilot could pull a lever and it would move the camshaft to its high lobe profile. this allowed more power and speed to let them get away. or so I am told by an old college professor...

Wnts2Go10O
10-03-2011, 08:18 PM
hasnt there been a nagging heat issue with the mag actuated valves? i know MB has been trying to come up with something. theres been stuff flying around since it was released they wanted to go to a 43 volt system.

i think hydraulic would be more feasible, less heat issues.

chuntington101
10-04-2011, 07:34 AM
hasnt there been a nagging heat issue with the mag actuated valves? i know MB has been trying to come up with something. theres been stuff flying around since it was released they wanted to go to a 43 volt system.

i think hydraulic would be more feasible, less heat issues.

I know Lotus where carrying out alot of testing. Think thye hwere looking to use a 72volt system.

Would hydraulics work fast enough?

Nereus
10-06-2011, 07:41 PM
I know Lotus where carrying out alot of testing. Think thye hwere looking to use a 72volt system.

Would hydraulics work fast enough?

The amount of work needed to move that pressure of viscous fluid at that speed accurately would be useless compared to the ease of cam actuated valves. Not to mention the large flow losses through those size fittings and valves. Also, as far as I know the gain Lotus was getting from using solenoids was rather minimal too, other than the infinitely variable part.

First off this idea has been around for a long time. UI perosnally haven't really seen anything come of it. Its a good idea, but i bet its a B!TCH toseal the thing under full working load!

The problem with these valves is that pretty much nothing beats poppet valves in effectiveness and ease of variability. Especially at higher RPM, the poppet valve acts as though it almost isn't there from the air's perspective and can also be used to effectively induce swirl, especially in 2-valve cylinders.

Didn't mean to come across as an *ss mate. sorry. :)

have you seen sleave valves? They where used heavily in British WW2 aero engines in the later stages of the war. supposed to give significant performance advantages of poppet valves (although they had aot of problems sealing poppet valves back in the 1940's).

Chris.

While this is an interesting concept and could probably be used to apply EGR to the ports themselves, again poppet valves will be more effective in not slowing the air flow. You also would need to take into account the compressibility of air at higher engine speeds. And you would also be using a free mechanism to induce F/A swirl, thus losing power.

stevieturbo
10-11-2011, 06:09 AM
It'll probably end up going to a rotary valve type system.

But it all boils down to cost. At the minute, valve/springs are just the cheapest option, they work very well, and work for a very long time.

Until emissions targets cannot be met with existing systems, doubtful they will change.

CharlieB53
11-21-2011, 01:59 PM
We have the technology, I just haven't seen anyone put it all together yet.

I've been fortunate to have had my hands in a number of shops, working for some pretty old guys, seen and done a lot, and often think too much.

Mercury Marine built a neat engine for the Corvette years ago that used a 4 valve head with two intake paths, one had a butterfly that stayed closed, using only one port/valve to keep airflow/speed high until engine speed and load require the additional flow of both valves/ports. The motor had a lot of promise.

Back in '79 while working in a bike shop (HD's and Kawasaki's) I was degreeing cams on a KZ900 and started wondering about how I could build a set of 3 adjustable idlers such that I could vary the LSA of the cams and also advance/retard each cam. maximizing HP and torque throughout the entire RPM range.

A four valve head, total VVT, dual intake path, need I say more?

c-ham
01-11-2012, 01:14 AM
i believe kawasaki's last Moto GP bike, before they pulled out of GP, had solenoid operated valves.

stevieturbo
01-11-2012, 06:29 AM
There is ample technology out there. Making it affordable, reliable and of enough benefit to make it worth putting into either low volume or mass production is a different matter though.

At the minute the only thing forcing some change, are emissions targets.