Yesterday's news and re-inventions that have been submitted to the Creativity Pool. See what they look like and where to get them.
By joseph ake
#1389
The engine could gain horse power by taking away the valve springs. In place the cam would be over the valves, the valve stem would hook to the cam lobe on the sides, contact on the face would be a roller. The engine could be reved very high and not float a valve.

Reward: a job and a peanutbutter and jelly sandwich
By dosefuk
#1552
sorry mate but you basic idea is already done. they have production engines which dont use any valve springs but use pneumatic technology to work the valves. produces more hores power then float springs and is less complex than your idea! :-#
User avatar
By Michael D. Grissom
#2157
The Wankel eliminated all the valves, springs, cams, pistons, rods, etc. and accordingly delivers a lot more power per ci while running much smoother.
They solved the rotor seal problem a long time ago and therefore are becoming popular in airplanes (FAA approved!). Too bad Mazda gave it such a bad name in the beginning that it's got a long way to go for full recovery in the car driving publics mind.

BTW there's a really neat animated Wankel engine on HowStuffWorks.com
User avatar
By FlatTop808
#2562
If I'm reading your idea correctly, you're saying use a cam to both open and close the valve. If that's what you mean, you're very late with this idea. Every Ducati motorcycle made these days operates just like that. Its called Desmodromic Valve Actuation. It allows them to use very aggressive valve timing with no float; snap it open, snap it shut. Its expensive to produce and a bear to maintain. It has two sets of shims per valve because it follows two cams, and they have to be checked and adjusted every 5000 or so miles.
And it doesn't free up power in the engine. Closing the valves still requires energy and the only place to get it is from the engine.
BTW, Peugeot first used this type of valvetrain on a race car in the 1910's.

http://httpd.chello.nl/~wgj.jansen/desmosys.html
User avatar
By Michael D. Grissom
#2566
WOW!!! -- that's amazing! Peugeot did that in 1910!!! That was incredibly precise machining for that era (even for shims). If this is true and I'm assuming it is, then, I'm really suprised that the French didn't win ALL of the air races of that period.

NOW it all makes sense that it only took the French about a year to design and build that precision KIT with perfect instructions as a gift to America that took us (USA) at least 3 years to assemble.
Attachments
P0005026.jpg
P0005026.jpg (19.65 KiB) Viewed 7637 times
By headwerkn
#3217
Formula One engines have had pneumatic valve trains for some time. Motorcycle racing will probably go the same way very soon - about 16,000 rpm valve float is a real problem.

Given the trend towards adjustable valve control systems in modern engines (ie. Honda's VTEC and BMW's VANOS) - which are currently mechanically-based and pretty darn complex - to get more power and efficiency out of smaller, less polluting engines, I'd hint that such systems will be commonplace in many production cars in the next few years.

The ability to easily adjust valve timing, lift and duration via a computer program, rather than hideously expensive metal cam shafts, will open up engine tuning all over again, just like when fuel injection replaced carbs.
User avatar
By FlatTop808
#3227
Camless engines are definitely in the future (near future, I hope). Several manufacturers have been working on this for years and Lotus just signed a deal with Eaton to pursue the technology. Infinetly variable valve timing would solve a whole wad of problems. Add in variable intake and exhaust tuning, which some cars and bikes already have, and variable compression and the engine can be made to do almost whatever you need it to do.
Aprilia is already using pnuematic vavles on its GP bike, along with throttle by wire. Its not really competetive but I'm guessing that's because its a triple and they don't have the money to compete with Honda and their V5 (why a V5? Because they're Honda. This is the same company that built a bike with oval cylinders). For the foreseeable future, bikes will stick with regular valves because they already can make more power than the rear tire can handle.
By Justin
#3294
I still want more: of more power that the rear wheel can handle.
Good idea though.. I also wonder if eventually they will (or have) control the valves electricly, with electromagnets..
OFFSHORE
Finger Wheel Fidget Toy

A three inch wheel with rubber grip on the outside[…]

Makeover of backyard

Nothing to share but I definitely want to see the […]

Sticking Games

No fantasy but real sports. Professional level foo[…]

This must be very useful information. Thank you ve[…]