Coates Spherical Rotary Valves
02-16-2004 | 07:04 AM
#1
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Joined: Dec 2002
Posts: 873
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From: Tacoma/Puyallup, WA
Coates Spherical Rotary Valves
I may be out of the loop, and this may be old...But I found this very interesting.
http://www.carcentral.net/content/ar...taryValves.php
http://www.coatesengine.com/csrv.html
The real magic of CSRV lies in the numbers; horsepower and torque to name a few. A stock 302ci 5.0L Ford small-block was chosen as a test engine to demonstrate the awesome characteristics of CSRV. The original, stock engine was dynoed at 260 hp and 249 lb-ft of torque. After the CSRV heads were installed, and with no other changes to the short block, the same engine churned out 475 hp and 454 lb-ft of torque! This is due to the reduction in frictional losses and improved airflow. Furthermore, the lack of valvetrain limitations allowed the engine to spin to 14,750 rpm. Since the lubrication system is not exposed to the pollution from the poppet valve design, the engine oil stays cleaner, longer. Other benefits of CSRV include reduced noise and a lower average operating temperature.
http://www.coatesengine.com/csrv.html
02-16-2004 | 08:22 AM
#2
Something tells me this is not an upgrade that can be done cheaply (i.e. under 10K). I also somehow doubt that you could spin a stock 302 Ford short block to 14,750 RPM and not have the bottom end come apart. I don't doubt that this would make significant power but, their example seems a little far fetched.
02-16-2004 | 08:44 AM
#3
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Joined: Dec 2002
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From: Tacoma/Puyallup, WA
I have no doubt that this would be very expensive. From the first link it says the original prototype was created in 1961, took 15 years to get it to run, another 5 to seal properly, and it's just now ready to be implemented. I'm assuming that in 40 years of R&D, they're able to back up their claims.
I think their hope is that automakers will start implemeting their system in engine design, which will drop the prices and make it more available.
I think their hope is that automakers will start implemeting their system in engine design, which will drop the prices and make it more available.
02-16-2004 | 12:13 PM
#5
I wanna see the rods not float at 14000RPM. F1 cars have to use hydrolic lifters to get those RPMs.
the theory of it is good, actual use they are ignoring the 100s of other reasons that there is a redline. I dont think engine makers design the redline over the seal limits.
the theory of it is good, actual use they are ignoring the 100s of other reasons that there is a redline. I dont think engine makers design the redline over the seal limits.
02-16-2004 | 12:13 PM
#6
I wanna see the valves not float at 14000RPM. F1 cars have to use hydrolic lifters to get those RPMs.
the theory of it is good, actual use they are ignoring the 100s of other reasons that there is a redline. I dont think engine makers design the redline over the seal limits.
the theory of it is good, actual use they are ignoring the 100s of other reasons that there is a redline. I dont think engine makers design the redline over the seal limits.
02-16-2004 | 02:38 PM
#7
These valves will never float by definition. Valve float is when the camshaft is spinning so fast that the actual valves are thrown clear off of the lobes and never really seal shut, allowing exhaust gasses and intake gasses to mix and preventing compression of any sort. These camshafts do away completely with the traditional valves and springs, with gasses passing through those colored openings (as they pass through their rotation, they will alternately seal and open as the openings allign with openings elsewhere in the head) you see there instead of passing through linearly reciprocating valves. Since the traditional valves and springs are done away with, there can never be any floating.
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02-16-2004 | 03:53 PM
#8
I think, with the advent of 40+ volt electrical systmes, we'll see electrically (solenoid) actuated valves soon.
http://www.pistonheads.com/news/arti...p?storyId=7005
(BTW, a switch to a higher-voltage vehicle would be great for all the car audio buffs as well, meaning lower amps required for the same power output, meaning smaller wires, heatsinks, etc...)
As far as the spherical valves, I wonder if they have any issues sealing them...? I thought I read somewhere that this type of system works great at WOT, but isn't so great for engines that need a wider rev range to operate in (read: production cars). I am sure you could vary timing on these as you can with cams, but who knows what additional complexity that induces..
Actually, after some more reading, I found this and answered some questions (while inspiring new ones, like how much does the "special material" cost?)
http://www.pistonheads.com/news/arti...p?storyId=7005
(BTW, a switch to a higher-voltage vehicle would be great for all the car audio buffs as well, meaning lower amps required for the same power output, meaning smaller wires, heatsinks, etc...)
As far as the spherical valves, I wonder if they have any issues sealing them...? I thought I read somewhere that this type of system works great at WOT, but isn't so great for engines that need a wider rev range to operate in (read: production cars). I am sure you could vary timing on these as you can with cams, but who knows what additional complexity that induces..
Actually, after some more reading, I found this and answered some questions (while inspiring new ones, like how much does the "special material" cost?)
Among the primary engineering challenges in the
development of the Coates head was implementing a reliable
seal between the combustion chamber and the valve, while
keeping friction at a minimum. The rubbing of metal against
metal, which results from a rotating surface moving over a
fixed one, usually causes substantial wear and lessens the
ability to form an effective seal.
Coates said that he has solved these problems using a
unique sealing mechanism with each valve. Although the seal
is fixed in the cylinder head, part of it moves in a linear
motion in response to cylinder pressure generated during
compression. As a result, the seal surface is pushed solidly
against the periphery of the rotating valve. The sealing
surfaces are, therefore, in contact for one piston stroke, or
one quarter revolution of the crankshaft.
The Coates rotary valves are fashioned from Nitralloy, and
the face of the seal is made from a proprietary carbon-
ceramic alloy. Both materials are highly resistant to wear,
and neither requires lubrication in the engine. "The seal
wears only 0.0001 inch every 25,000 vehicle miles," Coates
said. Indeed, the seal compensates automatically for wear
during engine compression by means of its linear motion.
A similar, but not identical, carbon-ceramic composition
is used in the bearings that support the shaft on each side
of the valves. Meanwhile, conventional steel ball bearings
provide support at opposite ends of the shaft.
development of the Coates head was implementing a reliable
seal between the combustion chamber and the valve, while
keeping friction at a minimum. The rubbing of metal against
metal, which results from a rotating surface moving over a
fixed one, usually causes substantial wear and lessens the
ability to form an effective seal.
Coates said that he has solved these problems using a
unique sealing mechanism with each valve. Although the seal
is fixed in the cylinder head, part of it moves in a linear
motion in response to cylinder pressure generated during
compression. As a result, the seal surface is pushed solidly
against the periphery of the rotating valve. The sealing
surfaces are, therefore, in contact for one piston stroke, or
one quarter revolution of the crankshaft.
The Coates rotary valves are fashioned from Nitralloy, and
the face of the seal is made from a proprietary carbon-
ceramic alloy. Both materials are highly resistant to wear,
and neither requires lubrication in the engine. "The seal
wears only 0.0001 inch every 25,000 vehicle miles," Coates
said. Indeed, the seal compensates automatically for wear
during engine compression by means of its linear motion.
A similar, but not identical, carbon-ceramic composition
is used in the bearings that support the shaft on each side
of the valves. Meanwhile, conventional steel ball bearings
provide support at opposite ends of the shaft.
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