Revolutionary valvetrain technology...
#1
Revolutionary valvetrain technology...
I post this here because the 'inventor' is american and he would like to see the "Big three" make profit of his design.
http://www.coatesengine.com/csrv.html
http://www.coatesengine.com/look_mom_no_camshaft.html
The spherical rotary valves have been designed for a while now, and they propose so many advantages and visibly no disadvantage compared to poppet valve engines that it makes me wonder why no manufacturer has bought the patent and started developping on this revolutionary design.
In the second link (for those that will read) you can read:
I would really like to see what teams of engineers can do, with millions in R&D, with this type of design. But again, I ask myself: If it's that good, why why hasn't anybody started designing engines with this?
What do you guys think?
http://www.coatesengine.com/csrv.html
http://www.coatesengine.com/look_mom_no_camshaft.html
The spherical rotary valves have been designed for a while now, and they propose so many advantages and visibly no disadvantage compared to poppet valve engines that it makes me wonder why no manufacturer has bought the patent and started developping on this revolutionary design.
In the second link (for those that will read) you can read:
Where the CSRV really shines is in its airflow potential compared to a poppet valve Bench-marking a 5.0 L engine from a Lincoln, the stock Ford casting (when tested at 28 inches of H2O) flowed approximately 180 cfm on the intake port at static. The rotary valve for the engine in comparison flowed a whopping 319-cfm at the same test pressure. Equipped with the poppet valve head, the Lincoln engine dynoed at 260 hp and 249 lb.-ft of torque. When equipped with the CSRV head at the same 5,500 rpm test protocol, it made 475 hp and 454 lb.-ft of torque, with no changes to the block or rotating assembly: The higher power was a result of diminished frictional and pumping losses, but the inherent airflow benefit of the spherical valve was the major contributor. With a conventional poppet valve, it can take 34 degrees of crankshaft rotation or more to reach a fully open position, wasting energy and limiting volumetric efficiency. With the CSRV, a comparable port area is exposed in only 2 degrees of crank rotation. The CSRV allows for superior surface flow coefficients from its spherical shape. With the standard 4-inch Ford bore, the factory poppet valve covers only 15.8 percent of the total bore area, while the rotary valve is measured at 20.5 percent.
Since horsepower is defined as work over time, the CSRV allows for an extremely high rpm potential. Test run at Coates' facility have seen a Ford 5.0 liter engine spin to 14,750 rpm! Though the CSRV removes the valvetrain rpm limitations, the need to have a rotating assembly that can withstand the engine speed becomes the essential element. Another benefit of this design is the extended oil change intervals, with the lubricating system not being exposed to the rigors and pollution from the poppet valve.
Since horsepower is defined as work over time, the CSRV allows for an extremely high rpm potential. Test run at Coates' facility have seen a Ford 5.0 liter engine spin to 14,750 rpm! Though the CSRV removes the valvetrain rpm limitations, the need to have a rotating assembly that can withstand the engine speed becomes the essential element. Another benefit of this design is the extended oil change intervals, with the lubricating system not being exposed to the rigors and pollution from the poppet valve.
I would really like to see what teams of engineers can do, with millions in R&D, with this type of design. But again, I ask myself: If it's that good, why why hasn't anybody started designing engines with this?
What do you guys think?
#2
Seems pretty interesting, and if its all its cracked up to be, maybe it will make its way into manufacturing. The only reason I see that its not being used, is Americans are so set in their ways, and dont want to try something new, so instead stick with something familiar.
#4
If I recall correctly, they had problems keeping the rotary valves sealed correctly within the head after extended use. Basically overtime the tolerences between the opening/ports in the head and rotary valve would continue to grow, and with no way to adjust tolerences without the replacement of the entire rotary valve, it ended up putting a hurting on the overall efficiency (power, mileage, and pollutants) and reliability of the design, as burnt and unburnted gas/fuel were allowed to escape throughout the rotary valves rotation in the head. There is definately a lot more power potential with the Coates head/valve design, or some type of electronic or pneumatic valve sytem in comparison to a traditional camshaft/valve arrangement.
Last edited by timeattack07gt; 05-16-2008 at 02:16 PM.
#6
here is some more cool technology
http://www.decuirenginetechnologies....glessvalve.php
http://www.youtube.com/watch?v=GXIdOTkJhEY
http://www.decuirenginetechnologies....glessvalve.php
http://www.youtube.com/watch?v=GXIdOTkJhEY
#7
10 years and it still hasn't been picked up by anyone. Looks like he doesn't have any good contacts/hasn't been selling is product well enough or it's junk and they automakers already turned it down.
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#8
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#10
HotRodGuy, that Decuir springless valve system is also pretty interesting. It looks a lot like Ducati's 'desmodromi' system for OHC engines, but with less complications. And it also works with pushrod engines too, I'm guessing we can eventually see those on production engines in the future.
Timeattack07gt, I know I read somewhere about the first SRV concepts having problems sealing properly, but they changed the rotary valve seal to a design that works much like piston rings. They say "a 100% seal is achieved" with the new seals. But I guess to have full credibility they would have to build an engine from an existing DOHC block (say a Ford modular V8) and run it in long term tests, including endurance racing conditions without loss of seal effeciency. If Coates can manage to do this, then I would be a believer that this might actually replace current valvetrain designs.
The upcomming mechanical engineer in me continuously wants to improve the modern internal combustion engine, to avoid being forced to drive electric cars with no soul.
Timeattack07gt, I know I read somewhere about the first SRV concepts having problems sealing properly, but they changed the rotary valve seal to a design that works much like piston rings. They say "a 100% seal is achieved" with the new seals. But I guess to have full credibility they would have to build an engine from an existing DOHC block (say a Ford modular V8) and run it in long term tests, including endurance racing conditions without loss of seal effeciency. If Coates can manage to do this, then I would be a believer that this might actually replace current valvetrain designs.
The upcomming mechanical engineer in me continuously wants to improve the modern internal combustion engine, to avoid being forced to drive electric cars with no soul.
Last edited by JN87; 05-17-2008 at 01:37 PM.
#11
I don't know why we haven't seen such technology used by automotive companies to date. I'm sure some of these automotive companies have the resources and money to make such a design work efficiently and reliably, or through the use some other type of much more efficient valvetrain setup. If you look at some of the crazy technology in current Formula 1 cars, you would agree. Not to mention this technology is all within the rule sets. If they were allowed to go all out, it would definately make for some insane technology developments, that could possibly carry over to future road cars. If you're interested here's a thread from F1technical which has bunch members discussing developing engine designs and theories. http://www.f1technical.net/forum/vie...php?f=4&t=4876 There are a lot of bright minds on this forum, you'll probably like it if you're into the mechanical engineering and technology aspect of cars. One of the guys aerodynamic designs was actually picked up and used by Ferrari two races ago.
Last edited by timeattack07gt; 05-17-2008 at 03:10 PM.
#12
With the research and developpement budgets of some manufacturers and race teams, evolution of the design would be tremendous, especially in race conditions. The rotary valves offer much better breathing and high RPM stability that racing engines would greatly benefit from. I agree that F1 engines really push the limits of technological developpement.
I suppose the the valve sealing issue will get fixed, just like the first Wankel engines had serious oil consumption and recirculating hydrocarbons problems, which were resolved in the most part with the Renesis wankel.
I browsed through that thread and some links, and there defenatly are some wicked engine designs out there. Pretty interesting stuff indeed.
I suppose the the valve sealing issue will get fixed, just like the first Wankel engines had serious oil consumption and recirculating hydrocarbons problems, which were resolved in the most part with the Renesis wankel.
I browsed through that thread and some links, and there defenatly are some wicked engine designs out there. Pretty interesting stuff indeed.
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