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What ever happened to Coates International?

They're still there -- http://www.coatesengine.com/

But still no product on the market. I first read about them in a magazine back in about 1993. 20 years gone by and I can't buy a retrofit head for a 4-banger. Seems their patents should be about up.

I see no evidence that the traditional piston and crankshaft, poppet valve, type of mechanism is going to be replaced by a new IC engine.

The "next big thing" for IC engines will probably be rotary valves or camless engines. You are right, though, that future changes will almost surely be incremental.

There have been many attempts over the years to supplant the traditional poppet valve technology in IC engines. Several engine designs already sport variable valve timing to control when and how much exhaust gas exits the cylinder. I have only heard of a few contenders that replace the whole valve train/gear train concept. The one that looks most intriguing to me is one I read about years ago in a hot rodder's magazine. (I forget which one, either Hot Rod or Car Craft) The Coates spherical rotary valve.

Why keep a cam if you're electronically controlling the valves? Just like ignition systems have gone to fully solid state, with very few cars having distributors any more, why not move to fully digital timing?

I don't know if you've ever had to compress a valve spring, but they're pretty pissed off devices.

The best thing we could do would be to move to some kind of rotary valve system - any kind, really. Because reciprocating valves have problems. They are what limits RPMs, which is why rotary engines have been known to reach over 10,000 RPM, and why a [very very built] small block tchevy :) with a Coates rotary valve system has reached over 12,000 RPM (can't find cite for that, but their page says "The comparative efficiencies of the spherical rotary valve combustion engine have enabled engine speeds of 14,850 RPMs."

We could make smaller, even more efficient engines by increasing RPM, but we don't do that because it causes valvetrain death. In order to get high RPMs, you need to be able to open and close the valves faster. Cams only open valves; springs shut them. This has two effects; one, there is a hammering process that goes on between the valve and the seat. Two, if the springs are not strong enough, they do not push the valve closed fast enough, and you get a phenomenon called "valve float". Solenoids can provide infinitely variable valve timing and duration, and through a shifting system (where the whole actuation system moves) you can provide variable lift. But as you increase RPMs, you need to increase the spring rate, and therefore you need stronger and stronger solenoids.

A solenoid valvetrain has been used in racing (I forget by who) but no one has managed to make a system suitable for the street yet. That's really too bad, because you could eliminate most of the valvetrain that way. But there are definitely serious implementation issues. Rotary valves are here now. There are competing designs, but none with pictures as pretty.

Is to remove the one of the biggest obstruction's to making more power...the valve. http://www.coatesengine.com/ I still don't know why every car manufacturer hasn't implemented rotary valves, it's got to be politics holding it down. Wayyy more power, better MPG, less moving parts, oil changes every 50,000 miles, it's ridiculous.

In the tune of saving energy a new engine rotary valve design has been developed which should drastically decrease fuel oil consumption as well as get more power from the engine. Sadly only a Canadian Gas company and British auto makers are seeing this as a good thing. Way to go for the retard and fuel hogging American vehicle manufactures. Maybe they will actually wake up the day after gas is over $5 USD/Gal at the pump. Probably not...

For more information on this design go to:
http://www.coatesengine.com/

There is already an electric "race car" - The Tzero from AC Propulsion, does 0-60mph in 4.7 seconds. Go to www.acpropulsion.com and read up on it, it's really a great piece of work. 200hp electric motor.

The original version used Lead Acid batteries but they have one now using Lithium Ion. The car can cruise for 300 miles on a single charge. That, to me is a real winner.

Lengthy (overnight) charge times seem less of an issue now; I get about 300 miles on a tank of gas in my current car and have to gas up every week or so. With a Tzero I could recharge whenever convenient, and not really worry about it, because *somewhere* within the span of a week I'm sure to get 8-12 hours of charge time.

I think there's a lot to be said for centralized emission controls (in an electrical power plant) versus millions of questionably-maintained controls in IC engines. However, there are also plenty of interesting technologies for IC engines that are worth looking into, like the Coates Spherical Rotary Valve Engine or the Roton Rotary Valve Engine. These new technologies hold a lot of promise for improving the efficiency and cleanliness of IC engines.

And let's not forget the venerable Wankel Rotary Engine and all the potential it has to offer.

But personally, I'm getting on the waiting list for a Tzero. The fact that their *entire car's* power to weight ratio is greater than *just the battery system* in the Honda electric vehicle says plenty, to me. These guys have their technology in order, now all they need is some investors to dump enough cash on them to go mass production.