Check out this new valve train system. It pretty much eliminates the need for almost all moving parts in a cylinder head. A friend sent this to me.. Is this new technology? It's the first time I've seen it. http://www.coatesengine.com/ o No:
That looks very interesting. :TU: I couldn't find any pics or videos that really show exactly how it works though. o No:
Like most "new" developments in the engine world, this one isn't new. It was developed back in the early 1900's. It failed primarily because of the rotating valve becoming carboned, or crudded up and eventually seizing I think. That is not to say that new technology like cleaner burning engines, better alloys, or who knows what couldn't be employed today to cure the problem. How do I know that and where did I see it? Heck, I have no idea, I've been reading about engines since I was 10. Some old book someplace.
I wonder if they've shown it to all the major car manufacturers. They probably want too much money for the rights.
That's a GREAT idea, how can I get one for my Buick??? :bglasses: Oh, yeah, for less than what I paid for my house...
you guys probably won't believe this but I actually thought of that exact concept while laying in bed one night when I was 12 or 13. The possibilities of it kept me up for hours. Then I figured someone must have already tried it because it's so simple and forgot about it. Years later I saw a couple of guys on TV trying to make it work on a race engine. The way I remember it they were Italian guys. Now I see this. I hope it works.
In case anyone cares.... Good friend of mine is working on his PHD in some flavor of engineering. Used to be in R+D at Honda. His somewhat simple answer below is that it doesn't work very well. The link in the middle explains the basic concept of what Honda used in order to give some semblance of turbulance to the incoming mixture and then only with limited success... Try to remember that the basic concept for our reciprocating internal combustion engines has been around for over 100 years. Don't expect anyone to deliver any BIG improvements any time soon. regards Ken QUOTE (from friend): Thanks for sending it to me - I had wondered if anyone would try ball valves again - Honda did it on GP bikes in the 60s/70s when most GP bikes were 2 strokers and Honda was determined to do 4 stroke - meaning the engines had to do ~17k rpm to keep up, thus the ball valves. Metulurgy and spring tech have caught up nicely since then, though. VERY fast, the shaping is necessay to allow the use of the cam drive gear set, to allow for correct opening exposure. The gearset isn't as clever as Honda's: they used a geneva gear that would turn full rotary motion into a turn-stop-turn-stop thing, pretty sweeeeeet. Check it out at: http://em-ntserver.unl.edu/Mechanics-Pages/em373honors-S2001/em373/geneva/geneva.htm There isn't a solution to the problem inherent in ball valves vs poppet - you need a bunch of turbulence early in the opening phase to estasblish turbulence in the cylinder (roll, tumble, & squish) to mix - poppets do this inherently, ball valves make for a nice quick opening but don't give you the initial turbulence onset. I would have scalloped the edges or made the interior of the vales rough as a cob. that probably wouldn't be able to mimick the ungodly high turbulence inherent in having a very small opening with massive vacuum on one side and one atmosphere on the other(Reynolds number about 20,000 - smooth, laminar flow is about 500 with 2,000 getting to transitional flow). Unless you've got a 20,000 rpm motor, this is a not a good solution, it will most certainly produce less power at low end with a small, if any, increase at the top end.
WOW! That Geneva Gear is something else, thanks for the link! :TU: Still, I can't help but think that something like this would be a step forward...the idea of a "straight pipe" into the chamber... o No:
Rotary valve technology This was in Popular Hot Rodding a couple of years ago, I think. The developer had several engines under tyest at the time. They had incredible power output, mostly because they could be built for very high rpm operation. Eliminating valve float means that the only restrictions on rpm would be keeping the bottom end together and filling the cylinders. So if you put a set of these on a short stroke big bore motor with a turbo or centrifugal supercharger..... Look out!
saw that like 8 yrs ago on a show on discovery channel called beyond 2000 kinda neat idea and they were a bunch of italian guys trying it on a race motor. I would think that it may work well on something with a super or turbo charger. imagine.... no chance for lifter noise !! -nate
The turbulance issue is corrected today with SPFI. Any remaining need for mixing with turbulence can be accomplished using a boundary device or interrupter in the valve. Still, it's not going to work well wehn you start pumping dirty, and oily city air through those precision machined surfaces. Racing maybe... The magnetically actuated valves being developer for F-1 have a real chance though. New technology, fully dynamic valve tuning....
