| Author | Message | ||
     Kajunman |
With the valve train problems Danny is having, maybe EBR sould consider the valeless technology from this company on the new line of production bikes. http://www.coatesengine.com/csrv-system.html Kajunman | ||
| Dannybuell |
wow! | ||
| Jdugger |
I wonder why we haven't see this technology in cars? | ||
| Nuts4mc |
ever try to "machine" a sphere?...then put precision holes in it? no valve alternatives... sleeve type engines: the Brit's had 'em in WWII - saw one out at an Airshow in Corona, Ca. the plane had counter rotating props! Sleeve valve inventor: http://www-g.eng.cam.ac.uk/125/achievements/ricard o/ I'm voting for direct injection two strokes...love the smell of Klotz in the AM.. http://www.synerject.com/di.html EEeeBR isn't the only one having "valve" issues...maybe he should sell one of his Fadals and buy another dyno... | ||
| Kajunman |
I wonder why we haven't see this technology in cars? It maybe a little more expensive than a regular valvetrain. }I know that at one time and maybe today, the company made replacement heads for the big block chevy and gasp one of the Harley engines. Kajunman | ||
| Barkbuster |
here`s some more. Whats holding this valve train back patent rights? http://www.youtube.com/watch?v=pDsRa4eT7co | ||
| Barkbuster |
lots of Harley conversions in the video. | ||
| Reepicheep |
My dirtbike is valveless.  That rotary valve setup is cool, I was trying to think through something like it a few years ago. Seems practical. Given how fast it could spin and how much it could flow, it seems pretty compelling. And it looks like an easy retrofit to an existing engine. Except I wonder what the piston has to look like in order to get good compression? That sphere would have to leave a lot of empty space the piston top would have to fill in order to get high compression. | ||
| Paulp1125cr |
That's pretty cool. I've been machining these pistons for a company in michigin that has an engine with two pistons per cylinder, check it out it's pretty wild http://www.ecomotors.com/ | ||
| Nillaice |
so they've solved the floating valve problem. piston speed is again the limiting factor and compression? you can still get compression up there with origional pistons if the bottom side of the bolt-on replacement head fills in the same gap that the OHV head shape did. but your probably gonna wanna change out the origional pistons for some lighter ones while you're in there. if youv'e got the $$$ for these fancy heads, you can splurge on some fancy alloy rods and pistons. | ||
| Froggy |
Would this setup mean no more periodic valve adjustments too? Or would this need some kind of similar maintenance? | ||
| Dennis_c |
No more valve adjustments  more riding time | ||
| Fast1075 |
"No more valve adjustments" Buy an XB! | ||
| Froggy |
I have two running XBs, each one needs more scheduled work than both my 1125s combined. Pass. | ||
| Boogiman1981 |
okay so this stuff has been around for at least 20yrs. why is it not all over the place? | ||
| Albert666 |
i remember seeing the coates stand at the autosport show, probably getting on for twenty years ago now | ||
| Boogiman1981 |
looks like they may actually be about to go somewhere. news reports are saying they are opening a factory to build the industrial engines for heavy gensets. maybe after a few years of them running right we will see more stuff. looked like they are licensing to china too. so that could be good or bad. time will tell | ||
| 1_mike |
jdugger et al - This technology "has" been used in cars...and "many, many" years ago. It's been used or better..."tried" in various types of engines, from drag race engines to smaller road race type engines While I only have some knowledge about the drag race engine, I believe the other engines had similar problems, though I cannot confirm that. In drag race form, a guy and his son spent a LOT of both time (as in years) and money building a Top Fuel/Funny Car engine using this design "valve train". They made up heads with different designed intake and exhaust ports, different shaped rotory valves. The engine just didn't make enough power to compete with the old...Chrysler Hemi copy. As I recall, there was also a galling problem between the rotory valve and the seat it rides in. They tried many different materials trying to find a compatable material. This was more a problem because of the chamber pressures caused by the fuel (Nitromethane) than any RPM problem. The Nitro engines don't run that high an RPM. Espicially with the advent of the rev. limiters mandated by the NHRA. They finally gave up the rotory valve design and went to the 4 valve head on the Hemi design block. While this combination did make more power, it still wasn't enough to keep up with the old 2 valve design. The did try a coupla years worth of cam designs to make it work, because they were the only guys trying these new designs, it pretty much blead their bank funds to the point of...needing to stop the hemorrhaging of their bank account. Mike P.s. - This rotory valve design noted above...was used back as far as about the mid or late 70's to no later than the early 80's. (Message edited by 1_mike on July 10, 2012) | ||
| Kajunman |
1_mike I am unaware of any galling problems that existed in the Coates designed big block Chevy head and the Coates designed Harley head. Could have been the use on a nitro engine or the head design. I am sure that if any problems did exist they have been solved long ago because using the valeless system in a harsh environment on an industrial engine would bring any flaws to the surface. Kajunman} (Message edited by kajunman on July 12, 2012) | ||
| Two_seasons |
The Suzuki rotary back in the '70 had my attention. Ah the sweetness of simplicity. | ||
| Brumbear |
The very nature of how it works has me wondering about one thing in particular. A poppet valve is forced closed with the upstroke of the motor making it a rigid contact point. The rotary valve is basically a bolted on piece of steel with the explosive force pushing away the rotary valve there just has to be a weak spot there? | ||
| Boogiman1981 |
The shaft seemed pretty stout. I wonder the same. The area actually exposed to the cylinder would limit those forces too. | ||
| Dcmortalcoil |
Mazda rotary engine!!! | ||
| Xnoahx |
These are rotary valves though, not rotary piston | ||
| Kajunman |
BUMP | ||
| Red93stang |
I like this engine design myself. http://www.dukeengines.com/ | ||
| Davefl |
I have two engines with rotary valves in the garage now(both old Vespa 2-strokes.) | ||
| Sir_wadsalot |
Screw that, too complicated, heavy diesel two strokes are the real valveless deal. There's holes in the cylinder wall, it pulls down, sucks in air, goes up explodes, pushes aexhaust out....it's crazy. If they could do that with gas engines...the rotary thing is neat though, basically rotary engine principal applied to valvetrain. Genious, but reinventing the wheel at too high a cost. Kinda like Desmo valves working out for Ducati, but you'll never see em on a toyota corolla. | ||
| Darth_villar |
Direct injection turbo rotaries, mark my words. |
