| Author | Message | ||
     Ralphthe3rd |
Hey, besides the fact that the engine is bolted to a Harley Clone Cruiser. http://www.coatesengine.com/motorcycle.html What do you guys think about this "CSRV" Rotary Valve head design? Is it too good to be true ? Aside from production cost and quality control, I don't see a down side to this design. If you see flaws...please explain them to me ???   | ||
| Ezblast |
Anybody know if this is a working deal? - just curious - sure sounds like a good idea! GT - JBOTDS! EZ  | ||
| Kevyn |
Looks interesting, unique and very technical. Time will tell. Engineer comments? | ||
| Charlieboy6649 |
Last year some time I saw a special on either Discovery or one of the like channels about a Bugatti (Is that spelled right?) motor with rotory valve technology. Can't remember all the details but was confirmed on that show as being very efficient and high revving. They were contemplating manufacturing them for F1 cars... | ||
| Ironiceberg |
That type of set up has been around, from like the 70s if I remember right. There was a drag racer developing them. The problem has always been getting them to seal. You got to remember that the compression pressure, heat, ect. is all in dirrect contact with the valve. How ever in the last 10 years or so a new company was working on them with good luck. But last I had read the materials needed where really pricey. But maybe them have finnaly got them into production. Cool! | ||
| Buellkowski |
Mazda now claims a higher level of durability for their rotary engines (remember the quick-wearing rotor oil seals?) through new materials technology. No reason why these heads can't use the same (expensive) materials. But wouldn't the benefits be marginal for low-rpm street use? Looks like a racing application only, to me. | ||
| Spiderman |
What gets me is how the cumbustion chamber looks with two sphers sitting in there. It has to have the wierdest flame front. It can't be good for a clean an consinstant burn over the top of the piston. | ||
| Wyckedflesh |
Coates had built a 22R Toyota engine in the 80's that ran something like 200,000 miles for a test. Constant run on a computer controlled variable dyno so it ran the gambit of loads and rev ranges. At the end they did a leakdown test. There was virtually no loss through the valvetrain. They were also using an industrial teflon/delrin sheet as a surface for the valves to seal around above the combustion chamber. | ||
| Easyflier |
I want to see the other side of that cruisers engine. Are the valves chain driven? | ||
| Hootowl |
The first Buell motorcycle had rotary valves. Think it'll come full circle? | ||
| Spiderman |
The first Buell was also 2 stroke. | ||
| Ezblast |
Still - that would mean that Buell would have some sort of leagal prior and therefore could develop such tech - so why not - sounds great so far - haven't heard a down side so far. GT - JBOTSD! EZ  | ||
| Imonabuss |
Yes, too good to be true. Not only are there horrible sealing issues, but take a look at the flow path through the port shape, if you want to do some 2-D sketches of the port as it is opening. Then do the same with a traditional valve. You'll see huge problems with the rotary valve design, and that's just the start of it. | ||
| Davegess |
A rotary valve on a two stroke bears no relation to this rotary valve except fro a shared name. | ||
| Mfell2112 |
I thought two strokes had reed valves. Mike | ||
| Ezblast |
So far I haven't heard of any bad sealing issues- if you have - where? - why isn't this idea persued - the wear factor of ziltch alone impresses me, and they are looking to it for formula cars - must be durrable under stress - so why are'nt we seeing more of it? GT - JBOTDS! EZ | ||
| Anonymous |
Ez - Do some more research and you'll find plenty on the sealing issue. I doubt if you'll read about it in Motorcyclist or on the Coates home page, though. Read real literature on this technology. Let me give you one more thing to think about, besides Imonabuss's accurate description of the flow issue. Look at the way a poppet valve seals when it has pressure against it. Then look at this valve design If it worked, don't you think it would actually be on F1 cars, not "being considered"? This concept has been around since the dawn of the IC engine, and hasn't made it for lots of good reasons. | ||
| Ezblast |
http://www.mmsonline.com/articles/1199bp1.html http://www.e4engineering.com/story.aspx?uid=1881a6ec-7ad6-4cad-b3f4-311ec01a2849 http://www.abbysenior.com/mechanics/valve.htm I'll broaden my search to engineering studies tomorrow - but what I've skimmed so far tells me only in dificulties in production machining such a thing - I'll keep reading! GT - JBOTDS! EZ | ||
| Charlieboy6649 |
Cool story about Roton. I'm no engineer, by any means, but I'm glad people try new things, or revisit the old. That is progress, even when it doesn't work. At least we learn it doesn't work! LOL. But when it does, ahh the possibilities... | ||
| Bomber |
rotary valves were used on aircraft engines (four-stroke) for a while . . ..sealing issues were one of the nails in the coffin . . .. as was extracting performance from them (see Buss's post on flow path) fun to see how little is really new, ain't it? | ||
| Ralphthe3rd |
 Well, I'm glad I brought it up ! Yeah, if you read all about it on Coates website- it looks terrific ! But.....? I will say this to "Anonymous", are you just jealous you didn't have a piece of the action ? It seems like they have spent years and mega $$$ on R&D and have had some major investors to get where the company is today ?! Wouldn't you think that they have come a long way since those early days ? I dunno, I'm no engineer- but I haven't heard alot of concrete evidence here to suggest that the modern tech isn't solving the old sealing issues. I do like the part of lower emissions thru less oil loss thru the valves. And wouldn't this engine have a high rev factor like a Desmo Ducati ? Sure, each cylinder on a V-twin would use a chain drive to those valves, but aside from that- not many parts to wear out or create drag and friction losses ??? If I'm totally off base... show me. Thats why I started this string. Don't compare this NEW Coates Tech to the old stuff... show me why todays designs aren't as good as the claims ? Erik B. and/or Blake, please educate me? ~Ralph | ||
| Ralphthe3rd |
But ya'll gotta admit one thing...it sure makes for a pretty top end !  And even if performance isn't as great as poppet valve engines...all the other plus's factor in to make a great -long lived/efficient/clean burning cruiser engine. I wonder if Jay Leno has one of the first Coates motorcycles yet ?  | ||
| Dyna |
If I'm totally off base... show me. Thats why I started this string. Don't compare this NEW Coates Tech to the old stuff... show me why todays designs aren't as good as the claims ? Erik B. please educate me? He already did, guess which poster above is him...& its not anon. | ||
| Ezblast |
http://www.kitcars.connectfree.co.uk/page45.html - so do you think they have really beat the old draw backs with the design? GT - JBOTDS! EZ | ||
| Ralphthe3rd |
 edited by ralphthe3rd on April 27, 2004 | ||
| Mpanebianco |
I guess I am one the the investors discussed as I have been investing in the parent company known as CIL for some 15 years. The motorcycle company CMC will roll out first and begin trading prior to the parent which will IPO this year. | ||
| Ralphthe3rd |
Hey Michael, Howz that Coates cycle working for ya ?  I'd really like to know how it performs. How many miles do you have on her ? And whats the power curve like? Please tell us as much as you can.... |
