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Rotary valve -- someone finally got it right?

Posted: Mon Dec 11, 2006 2:23 pm
by bryson
http://www.v-eight.com/multimedia/pdf/AutoTechBRV.pdf

Very interesting. It kills me though how these restrictions are made for F1 -- they are supposed to be pushing the envelope and developing new ideas to get around certain restrictions. It advances the forefront for automotive technology, why ban this type of technology? It's Formula One, you can't do things to make the sport "more competitive" -- there's nothing higher! That's like telling NASA not to use a certain type of rocket because it's not fair to Russia...

I think that if someone is finally figuring out how to get a rotary valve to work, then why not use it? I can't believe that pneumatic valvetrains are allowed, but rotary valves aren't. Which has more potential to actually be used in production cars? Which is a larger, more significant jump in automotive technology? Hopefully some other company will pick this up, or maybe Mercedes will continue to pursue this for their production cars.

Posted: Mon Dec 11, 2006 2:35 pm
by Shaun41178(2)
Interesting read. What I think is cool is how high of a CR they can run with that setup. And thts with conventional fuel too.

Add E85 to the mix and you can add more CR. it also burns cleaner. With CR around 15:1 or higher with E85, you would probably see as much power output as a conventional engine on conventional fuels. With this design you might be able to do 18:1 compression with E85, and still be able to run a turbo. Talk about big power out of small engines. Which would be great too for fuel economy.

50 mpg 300 hp 1.5 liters.

Posted: Mon Dec 11, 2006 3:06 pm
by Kohburn
pretty similar to the rotary valve head i designed for to bolt to the 60*v6 about 7 years ago

Posted: Mon Dec 11, 2006 3:28 pm
by bryson
Also -- imagine the space savings. It's got the size advantage of a pushrod engine (probably an even smaller head) with the airflow advantages of the rotary valve. The very reason that the LS7 isn't DOHC (and the N* isn't 7L) is no longer an issue. Imagine a 7L engine the size of the LS7 but with airflow characteristics that surpass the nicest production DOHC engines. Imagine the weight and size savings in motorcycles -- scary! I've seen several different designs, but this is one of the first I've seen that incorporates the "valve" and port into one. The idea that I had in mind was kind of a larger "camshaft" with a rectangular hole through it and a typical port, but this seems much better.

Posted: Mon Dec 11, 2006 3:48 pm
by whipped
I'm glad they used cylinders....... that other one with spherical ports/valves/whatever was overcomplicated.

edit - these:

Image

Posted: Mon Dec 11, 2006 4:53 pm
by Pyrthian
nice
and, yes - F1 should not ban this tech. durability needs to be evaluated. how long will these things work & stay sealed. that one of the problems with RX7 rotary (wanklels) is they just cant keep the seal very long. I expect these will have simelar problems - large sealing surfaces

Posted: Mon Dec 11, 2006 6:27 pm
by teamlseep13
Sweet read.
As Pyrthian said, sealing is the issue.
You could do it with some expensive, low wear, low thermal expansive material like ceramic but that problem is just that, its expensive.

It sucks that F1 banned it but I understand why.
Sure they are supposed to be pushing the limits of technology but at the same time they are trying to have a safe racing league. Adding this technology would increase power(faster cars), decrease weight(even more speed) and require a complete re look at the current engines for all teams.
So faster cars are more dangerous and new tech liek this that will need more than just a head swap is pricey.

Posted: Mon Dec 11, 2006 8:25 pm
by p8ntman442
Customer>>>>I need my valve shaft replaced.
Mechanic>>>> :scratch: $1 Billion please

Posted: Mon Dec 11, 2006 9:17 pm
by whipped
heh... 32 valves x $17 > 1 billion$$$

Posted: Mon Dec 11, 2006 9:24 pm
by befarrer
Speaking of a differnt type of valve-train, have you looked a Ducatti valvetrains? They have no valve springs.

http://www.ducatitech.com/info/desmo.html
Image

Posted: Mon Dec 11, 2006 10:13 pm
by TrotFox
All I can say is, "SUCK!"

I'd love to see how this would do on a real-world engine. If the seals would hold up it'd make for one bada$$ engine!

Those Ducatti valves are also nice but if the slightest thing gets out of alignment or worn.... not pretty. ; ]

Red 5spd Formula
Trot, the gray, fox...

Posted: Tue Dec 12, 2006 8:25 am
by The Dark Side of Will
Desmodromic valve actuation is a hold over from the days when there wasn't any good spring steel in Italy. Nowadays it's as old tech as most people think pushrods are. Ducatti uses it for bragging rights because it's cool, but it's entirely unnecessary with modern valvespring tech.

Posted: Wed Dec 13, 2006 8:16 pm
by S8n
The Desmo system works well due to heavier valves used in the big v-twin, compared to a Jap I-4. But it's still old technology.