I remember reading about rotary valves decades ago in Popular Mechanics, Smokey Yunick was playing around with them. The inherent problem was that while poppet valves seal tighter when subjected to pressure, rotary valves suffer from blow-by. Similarly, poppet valves have no problem with thermal expansion and contraction, but rotary valves very much do.
The sealing dilemma of this rotary valve design is obvious. With compression, conventional valves wedge tighter into their seats, and continue to bed as they are run in. Ever since unleaded gas required better valves and seats, conventional valves with just regular oil changes and belt maintenance commonly go for 100,000-250,00 miles with no issues--- frequently still passing emissions tests with like-new performance. These?
These are all issues poppet valves suffered in the early days - the real reason they are not developed further is, whats the point? All manufacturers know that ICE engines are history so why spend billions making a better one?
@@piccalillipit9211 Good point, though I suspect -- I'm not a mechanical engineer -- that the basic physics of increased pressure naturally sealing poppet valves tighter but doing the opposite for rotary valves, is a fundamental problem. Regardless, I think you're right, it's probably an irrelevant point because the writing is on the wall for ICE engines.
@@tinetannies4637- Yeah I think if they wanted to make it work they probably could. Im increasingly of the opinion that as good as electric cars are, they are not the solution. IMO - Some people need electric cars. The majority of people need excellent mass transit, busses, trolly busses, trams, light rail and high-speed rail. And some people need ICE engines that are high quality and efficient. But we are all suddenly obsessed with battery cars.
I remember reading about these Coates valves in the 90’s. If this design has been around so long, why hasn’t it shown up in the mainstream? Still has sealing issues inherent to rotary valve design.
Even if it seals well indefinitely, the performance gains will never outweigh the manufacture cost. Carbon seals, ceramic bearings, extremely precise spherical grinding... Nah, cams and valves. DOHC with VVT comes very close in performance for a fraction of the cost.
IIRC, Coates wanted a LOT of money for rights. The Japanese automakers were interested regardless. However, Coates wanted the product to stay in the US, with US automakers.
In the early 1960s a company called Southcotts built a rotary valve head for a 6 cylinder Holden motor. This motor was raced in a speedway midget with moderate success , but sealing prevented it from achieving its potential. There are pictures on the internet look it up. PS I lucky enough to see it race.
That Holden motor needed a supercharger so it could get the air into the cylinders, as I remember. A guy named Dunton was involved in the design & building of the project.
I actually do know a little bit about Coates International. I worked on a team developing cylinder heads valve covers front covers and intake and exhaust manifold at a foundry for an 850 in.³ engine line 6 engine with coats spherical valve technology. I have met George coats personally and done a tour of his shop. This technology is not phony, but I am aware of how big business are looking to buy the technology so they can shelf it. Coats wants his technology to be used all over the world. That is why he will only deal with businesses that will buy a license and pay a per engine royalty of $50. This way he can guarantee that the technology is not buried.
More engine technology I've never heard of. Where the hell do you find this stuff! Seeing how the rotary valves work, they are almost common sense. I'm surprised they haven't been put into use. Keep these excellent reports coming.
They haven't been put into use because it's a failed concept lacking adequate airflow with poor combustion efficiency and it's heavier and considerably more expensive than a traditional setup that makes more power, is cheaper, and weighs less.
About time valve technology moves forward. Seems this idea took a backburner from years ago. Finally things are going forward. Way to go COATES !!!!!!!!!!!!!!!
I first saw the coates design more than a decade ago, and this design first popped up in the 1920's or 30's, and it has gone nowhere meaningful since then. If this was really a revolution in engine technology there has been ample time for it to be adopted industry wide. The fact that it has languished in obscurity for almost 100 years is enough evidence that this is not the revolution that some think it is.
Well stated logical deduction Matt. But I seen a racing engines side by side one tappet one rotary. The rotary outperformed the tappet. The problem is I do not remember by what amount of extra power. Sorry Matt. @@mattzimmerman5967
Driving4answer made a great video on this subject, he said that it's shortcoming are that it don't seal the cylinder properly during it power stroke therefore losing power
Except this does not operate with a same principle. The rotary valves on his video had inlet and exhaust port channels going through them, that is not the case with these spherical ones.
Doubling horsepower doesn't sound like losing. If they make it legal on indy cars and Nascar it won't be long before someone figures out how to fix the blowby problem. There's gotta be a way, some type of clever groove or chall or something. There's gotta be a design solution.
I remember reading about this , probably in the late 90’s in Hot Rod or perhaps Popular Hot Rodding. Always wondered what became of this technology. Guessing that there are sealing issues that arise after some time, similar to the Wankel….
Sealing issues were solved by the 90s. The guy worked on the design and the seals since the mid 70s. Finally found a carbon/bronze ceramic seal that worked.
Sometimes an idea is too good. Sometimes the forces that be fight against good ideas. After all, how many stories have you heard about carburetors that produce 100 mpg only to completely disappear and the inventor with it!
@@90ForLifeTeam A car can easily get 100 mpg. The problem is it will suck at acceleration, have minimal load capacity and just be too slow for road use. Conspiracy theory believers are Not the sharpest tools in the shed.
I love how the promo video of poppit versus rotary valve power comparisons shows a songle carb versus a four carb setup. Not to mention the rotary valve would also cause a different manifold design thus changing even more variables.
Simple reason is the poppet valve engine can't flow more air than the single carburetor can flow. The rotary valve engine has much higher air flow and the carbs and intake then become the limiting factor. If you restricted the air flow on the rotary valve engine of course it wouldn't make more power but that would make no sense whatsoever...
@@kennethney4260 and if you had oversized valves coupled with ported manifolds you would also get higher increases in horsepower. My point was they were comparing two completely different setups rather than comparing air flow numbers.
The reasoning you use to convince people to subscribe to your channel ( and if they don't like you, to unsubscribe) was enough to persuade me to subscribe, before even watching your video! 😁
Am amazed we quit hearing from the Coates engine, sounded like a good alternative to the valves today. Not sure if it was a scam, but hey, there are so many out there, not only in the automotive world. Cheers!
As I posted elsewhere, rotary valves suffer from blow-by and thermal expansion/contraction, two things poppet valves are inherently immune to. Poppet valves naturally seal tighter the greater the pressure. Rotary valves, on the other hand, behave the opposite.
I have a sketch of a type of rotary valve head design that can use cam timing and the amount of open time. The key to my design is that the rotary valves don’t rotate 360* but act on a cam design that opens and closes the valve with 1/10 the weight of a conventional valve spring. No patent yet but would like to experiment with it first.
This has been around for years, I recall seeing a yt vid on it at least 15 years ago. And other manufacturers experimented with it in the 1950s, one of which was Norton motorcycles. I always ask myself why it's never been adopted by the racing world as they are are constantly looking for a competative advantage, especially in F1. One reason may be that they now use electronically controlled solenoid valve actuation, which means valve timing and opening are continuously variable, so the advantage of rotary valves may not be worth the cost.
One of the big heat input in engines is the valve train, roller lifters and roller bearing rockers have helped eliminate some of the heat output, but spring pressure for seating valves also creates heat. A rotary valve would need to seal of course, but just like poppet valves they would need to be able to transfer combustion/ compression heat away from the actual part to maintain thermal expansion and not overheat. Likely a lot less friction loss , less energy to operate , higher flow all contribute to higher efficiency. Sounds like a great idea, just get it implemented.
That spherical rotary valve assembly looks hefty to suggest parasitic energy losses from inherent inertial disadvantages. Improved power, efficiency and heat dissipation advantages can only be offered at a constant engine speed but not in real life frequent engine speed change scenarios. The increased inertia of this system will requires more power robbing low to high engine speed shifts which in real street or track driving will translate into worse acceleration performance, more heat retention once the 'deep'heat sink' assembly becomes saturated, and less efficient energy draws when repeatedly going from slower to faster speeds. This system would be more suitable for high rpm drag racing combined with heavy clutch construction.
Every technological problem can be solved, ( time, money, and effort). Rotary engines have come a long way, as well as hydrogen power, and look at the strides that toroidal props have made. Shout out for all the "backyard " mechanics that keep on keeping on!
Progression of the aspin valve from the 1930s. The only efficient rotary valve engines that I can think of are two strokes using disc valves. Rotax 256 and it's variants - 100hp from a 250cc engine.
There have been a number of rotary valve designs over the years, a conical one with the axis inline with the bore, a cylindrical one across the bore like the Coates and of course the sleeve valve. They all develop more power and are smooth but they also all have problems with combustion chamber shape and oil consumption as the rotary valve must be lubricated. Coates and others have tried ceramic bearings but like ceramic pistons, this never quite works. With all rotary valve designs the lubricated surface is open to the combustion chamber at some part of the cycle so oil gets burned. But look at the freevalve technology, it too promised much but a few years on we are not seeing it in widespread use. Poppet valves are not ideal but they are well understood and they work well enough. We know how to build DOHC variable valve timing engines, (I drive a 30 year old Mercedes with this tech) but what engine does everyone want to fit, an LS, a push-rod engine!
Every one says "COSTS" they forget just how much COST went into getting the IC engine where it is today! That compared to the production of parts that are considered too expensive today, consider the "Cost" of research/machining development that went into the final Merlin aircraft engine!
I remember seeing this technology in a Popular Hotrodding Magazine in the 1990's and there was an actual name other than Cotes attached to it, That name was Ryan Falconer. Ryan was an engineering maverick that specialized in gas engines and was always trying to improve efficiency (Efficiency=more performance that can be obtained). He's known for some engine designs that were either used or considered for indy, A V12 as well as a 3 cylinder harley based engine, one of which was put in a custom chopper for the Great Biker build-off series
Have you looked at the Bristol Centaur Aircraft Engine that powered the Hawker Sea Fury Aircraft at the end of WWII and through the Korean War for the British Navy? It was touted as the epitome of technology in Reciprocating Aircraft Engines before they were abandoned in favor of Jets. It was a very powerful .Radial planform engine. I am not clear on the exact engineering of the valve train so cannot compare it to the Coates.
This is more what I had in mind; but i never thought about capturing the charge in the shaft to wait for a piston cycle. Perhaps it's just best suited for forced induction 2 cycle applications.
I remember thinking about rotary valves around 20 years back and telling an engineer friend, and he showed me the Coates rotary valve sytem on the interweb, surprising they have not made more headway since then, seems all is not kosher with them.
I actually had the exact same idea back in the late 60s (I was 12), but nobody took me seriously, and I didn't have the means to develop prototypes. But I did do research in the US Patent Office, and grew convinced that nobody else had a patent for the same idea. Now that I'm nearing retirement, I suppose I should pay them a visit - - just for the bucket list.
I have seen a motocross engine, that was 2 stroke 1 cylinder that I think bombardier made. It had a single spinning plate for intake and exhaust. The engine was open and was being worked on at the time. Iwas told it could reach rpm of well over 10,000. I would say it was in the early 80s. I though that was very interesting at the time, and still do.
Coates had a building in Wall Twp ..I visited their shop in the early eighties..what’s amusing is their shop coats…somewhat pompous..but what caught my eye is the bicycle cable that was their throttle control…it’s just flopping around At that time ad when your video shows the only production format.that accepted their design was the ford small lock because no center head bolts…such as Chevrolet At that time I owned Performance Racing Engines in Point Pleasant Beach and visited their shop….nothing was going on and the limited equipment was a Tree milling machine and a lathe the dyno was what you show as is the Coby throttle A lot of undocumented claims were made but as I offered a mustang chassis to put there mule into the car for some 1/4 mile drag tests….they denied and at that time were only talking about ceramic spherical seals They were also looking at the Mercedes twincam inine engines because of the permitter head bolt arrangement.but I don’t think it happened
Sealing the air inside the combustion chamber is an issue. Air leaks out of the valves it’s a great idea and maybe some day they’ll have a material that can seal better
I see a couple issues right off the bat: First, keeping that rotating valve assembly lubricated will be a chore. That's a whole lot of friction surface in the hottest part of the motor. Second, although a turbo can solve the problem of air volume on the intake side, the exhaust side will need a rotating chamber volume at least equal to that of the cylinder volume, or else you are compressing the mix twice. Such a volume would make the head assembly so freakin' large that it might make the motor impractical.
The reason it didn’t work is because the rotary valve is like a rotating drill bit and at the point where cylinder pressure is sealed the constant rotation quickly wears that seal and you began to have cylinder pressure leaks . The standard tapper valve statement does not exhibit rotary wear on the seal surface and so it has the longevity needed for 100,000 plus miles. Among other problems that I don’t feel like elaborating on here
Sealing is complex on these rotary valve engines. . Slight combustion pressure is lost but can be overcome. .I think durability and cost is a factor why we're not seeing these engines
I remember when this first was announced. It was all a buzz in racing magazines. Definitely a game-changer. Although it would have greatly benefited the automotive performance industry. The real threat would have been to engine efficiency which would have impacted big oils bottom line. For anyone that has been paying attention when disruptive technology in automotive History (i e. The 100mpg carburator) there are those that will not allow disruptive technology to come to the masses. People that have invented these disruptive technologies have either disappeared quietly or have died mysteriously. Those that did sell out to big oil promptly had their patents shelved. For those that think all this is too crazy and conspiratorial, you need to read Confessions of an Economic Hitman. It more centers around how countries historically are coerced into falling in line one way or the other. If some foreign president isn't playing nice with some select corporation an elite representative is sent to meet with him with a suitcase full of money in one hand and a gun in the other. And that's how it's done.
Apart from the sealing issues, I remember reading or hearing about the airflow eventually choking itself at higher rpm's due to the speed of the air reaching Mach speeds. Not sure where I heard or saw this, but it has always stuck with my memory.
I first saw this type of technology back in the early-mid 1980's, don't remember the developer but it seemed as though the initial problem had to do with carbon buildup on the lobes and causing failure of the sealing ability. Maybe it would be better suited to a gaseous type of fuel such as propane. Is a shame that it can't be resolved as it would simplify the valve train assembly quite a bit.
Thank you for the information, do you know of fuel efficiency and emissions. Years ago always thought of rotary valves would be better. Have you heard about the Achates motor, also look up Achates Ford f150 and the Achates truck motor. Don't know where it is on the development stage. Again thanks for your information, gives me information on what is happening in the world
well you are certainly right about the poppet valves being a really weird thing. I know that Kawasaki used a rotary valve in some of their two strokes back in the early 70's, the valve system worked but the bike had so many other flaws that the value of the valves was easily over looked (noteworthy problem, the ignition sparked sometimes and was only loosely connected to the piston movement). Now as far as this goes, it looks to me like the design of the compression chamber might have been part of the problem. The sharp edges of the ports would certainly cause detonation (I might be wrong but I do not have a good design blue print). Still the piston engine needs better valves. The two stroke diesel idea using spark ignition (mazda and others) seems worth more effort and some kind of 4 stroke application might work out. See 'Driving for Answers' for further discussion
14:1 is still done with traditional valve designs. It’s just more common in a motorcycle engine than a car engine. But even the Mazda Miata engine has a 13:1 compression
I wonder what the fuel consumption of the Coates design was in comparison with the "normal" engine. The Wankel engine was also great in theory but in practice the rotor tips wore and fuel consumption was a BIG problem
I remember looking at a video on these valves in automotive class back in 2002. They had a Harley Davidson with these rotary valve heads and a few four cylinders and the V8 small block as shown. Cool design but i guess the valve isn't cost effective to produce.
I read about these type of valves in the 1970s just out of high school. Evidently they were not reliable enough for production. Maybe they’ve improved them by now.
No valve springs, no valve springs float at high rpm. Also, the timing can be fixed on the fly with variable timing added. Then there is the ease of use and durability seems to be a non issue. Down sides?
I guess that a rotary valve applied to a compressed air engine would avoid most of the problems in an ICE which are primarily from combustion heat and pressure, and lubrication oil being burnt.
@@PRH123 i like the "half an hour"... rather generalised, isnt it? no other option, say, bigger tanks or smaller capacity engines in that general statement? its always 'half an hour"? and you missed the main point... ALL IC engines are running on compressed air. they just add fuel, ignite it, thus raising the temperature of that air. that as per charles law, increases the pressure of that air. which can then deliver more work than it took to compress. engines dont run on fuel. they run on AIR and HEAT. heat most often being obtained via the combustion of a fuel.
Interesting idea. I'm not convinced, yet, that the benefits of a spherical rotary valve over a cylindrical rotary valve would justify the higher production cost involved.
I had a 1969 Chevrolet 350 back 1976 that I put a one rotary valve with intake and exhaust same tub to reduce the temperature. Instead of 2.02 intakes and 1.65 exhaust, they were 3.50 intakes and 3.50 exhaust. Could not get the rotary valve to seal!
A guy in the uk built a historic race car running these valves and used them successfully. This was before this company. He passed away however his car is still going and still in use.
@thorman1742 yes built by Ralph Watson I believe. The engine had never been opened up in 30.000 miles which for a race car is very impressive and the reason it was opened up was due to a failed spark plug. Think it's tip broke off but the valves were still absolutely fine.
Winded why the use of spherical valves rather than drum type I applaud the use of carbon ceramic surely they could run the carbon ceramic housing and seal in contact with the valve wirhout probs this would surely create a good seal especially spring loaded still be a lot less drag and power sap in the valve train 👍🍻
Others below have commented that this isn't a new concept, which doesn't mean it isn't a good idea, but I can see problems that need to be overcome, some of which may be insurmountable. There is one advantage--valve float at high rpm would be eliminated. In the past I've worked on evaluation of alternative engine concepts, and quite often new concepts serve to illustrate the advantages of current practice.
I think they got into industrial generator motors minimally. At one time they offered manufacturing of heads for any engine you wanted. Hot rodders just wouldn't get behind it. I personally would LOVE to have a set and turn a drag engine to 20,000 rpm.
Well this technically is old, but perhaps technology has advanced enough that the leaking and blowby on the combustion stroke can be eliminated or reduced enough that it isn't an issue. If you look at it, it seems like a great idea since the energy used to open poppet valves is a drag on the engine, plus cams, lifters and valves do fail and can cause catastrophic damage. A rotary valve system would greatly reduce the parasitic losses and eliminate catastrophic engine failure when the valve train has a failure. Hopefully material science can make this possible and prolong the use of internal combustion engines in vehicles for longer with reduced need for fuel and less emissions.
How does this system deal with carbon build up. I know direct injection alone causes carbon build up in the intake. How often do those roller valves need to be cleaned?
Rotary valves should be a lot smaller, and sitting in a machined bronze case so it can seal and be lubricated naturally. Adding a small oiling jacket on the shaft can be done to add a very small amount during running. I would imagine oiling it too much will just result in burnt oil in the combustion chamber.
Sleeve valve engines have been around for over 100 years, and do well with lower compression but the real next big devepment is for camless electronic poppet valves.
This concept has been around for decades, but at present the complexity of the components and the materials required simply make it a good idea but to make it mass production cost-effective simply isn't there.
I have thought about something along these lines before. The obstacles are not so much efficiency or breathing, but chamber sealing for combustion and price of production. And then come carbon concerns: there is a constant burnishing of rotating parts exposed to combustion byproducts. Complex machining gets expensive - try working on a hagglund [hydraulic] motor and you get the picture. I'd like to see this engine concept work , but.. price point vs function? Mass produced engines stick with traditional valves. If this tech was better... F1 would have had a go of it already. Where could this be useful? Maybe to regulate a high boost system to get away from higher valve spring pressures and free up some power... but that's extra weight. Clocking boost pressure off without changing blower speed when intake valve closes is what I picture. Maybe this finds a marine application.
Interesting concept but sealing and wear would be concerns. And spinning an engine to 14k RPM only works when the bottom end has been built to withstand those forces.
Use it like sliding valve, adjusting the intake instead of measured cups. Instead of full rotations just a few degrees will open and close the flow!?!?
Just looking at the mechanisms it should be cheaper and less complicated to manufacture but the seals between the valves and the combustion chamber is probably the issue, thus you can’t maintain the seal for a long time of operation
I would think that super charging and or turbo charging is cheaper and better whilst achieving the same result. To be better than existing the new equipment has to have a number of better advantages all at the same time.
Maybe letting the ball float just a bit, rather than being firmly attached to the axis it turns on, would help. Cylinder pressure would then tend to force it against the opening the ball is blocking. The resulting narrow passageway would discourage leakage. Further, it would be nice to limit rotation of the ball while it is sealing against combustion pressure. No reason the shaft it turns on has to rotate at a constant rate. There are lots of linkages that can accomplish that. For example, a windshield wiper linkage fully stops the wiper rotation at two points in the cycle. Nothing I’m suggesting is terribly new or innovative. Certainly many good minds have contemplated this problem for decades or even a century.
15:1 and higher, thats could be interesting, because we already use 14:1 compression ratio, when we tune an ordinary alcohol powered engine (It came with around 12.5:1 from factory because It is bifuel, need to run with Gasoline too) specially 80's and 90's alcohol engines
This will work great until carbon builds up on the exhaust valves, then things start to break, maybe a 10k mile disassembly schedule for the cylinder heads?
