I don't think his definition of "fix" is the same as mine. I guess it depends on whether you have enough brainpower to operate the anti-vapor valve or not. Personally, I don't care to have the car or garage smelling like gasoline, so I prefer to avoid the fumes.

A rotary (Wankel) engine has a triangular device that acts as the piston, which rotates in a chamber close to a figure 8 shape. Each side of the triangle acts as it's own piston as it rotates, first intake through a port (no valve) then compression, detonation, expansion, and finally exhaust through another port (still no valve).
Radial engines (what I think you meant) are relatively normal piston driven engines where the pistons are arranged in a circle around the crank at a 90 deg angle from the cranks rotation. These are usually used in prop driven airplanes.
This motor arranges the pistons in the same orientation as the cranks rotation...a 90 deg difference from radial engines. This makes it far more compact, but also puts the pistons in a single, rotating, revolver like arrangement of cylinders. It's a bit of a combination of rotary and radial engine features.

I'm not sure how much credence I can give the wiki page...I note it claims things that are obviously wrong, like "the design does not have a long lifespan when compared to other engine designs due to large numbers of moving parts" while in fact this motor has far fewer moving parts than normal motors. It did make some good points, like the first one that occurred to me about friction, but also made some bad points such as claiming 'mechanical complexity' as a drawback, while in fact it seems far more simple than normal motors.
"extra complicated machined parts" also exist in normal motors, and can be made fairly cheaply and easily in bulk.
Excess use of oil is an issue, but one they should be able to solve with proper machining and materials. Low RPM is fine for many applications, like a generator, so long as it's efficient it's fine and might even be better. Since you get high torque at low RPM with this design, low RPM seems to be ideal.
They claimed it had comparable horsepower to the same displacement normal motors in the prototype...if true, that point is moot.
Actually, there seems to be less moving mass in this motor, consider the mass of the crank shaft and counterbalances, connecting rods and pistons, the camshaft, rods, lifters, rockers, and valves. This motor only had a compact 'crank' and the connecting rods and pistons, and the output shaft. That's less actually moving to my eye.
The 'potential for explosion' was claimed on Wiki to be a design flaw of the case thickness around the 'crank', which could easily be thickened if it doesn't have to fit inside a torpedo....potential removed.
I'm not saying it's perfect, or necessarily even feasible, but it does seem to have more going for it than you give it credit for and is worth following it's progress to me.

Revolutionize, probably not. Be an improved option over 'regular' internal combustion in (apparently) weight, size and efficiency, maybe. This seems to be a great option for a hybrid. Being smaller and lighter is what you want in an energy efficient vehicle, as is fuel efficiency. Since fossil fueled vehicles will be the norm for the foreseeable future, any step towards making them more efficient is a good thing (although not the end goal, true enough). This seemed to have many advantages of Wankel motors (rotaries) without the efficiency problem due to low compression/incomplete combustion. 14:1 on pump gas is INSANE! My offroad race motor is only 12:1 and it needs trick racing fuel.
Also, as far as simplicity, this had no valves and assorted crap, just inlet and outlet ports (from what I understood anyway) like Wankels. That's a HUGE jump in simplicity, with an entire system eliminated, so there's far less to break/wear out/need tuning. IF manufacturing cost can be reasonable, I see this as a great step forward possibly making hybrids more acceptable to many more people.

Sure, yea, right now it is, but the way things are going it's not far of that a majority of new cars are going to be electric or at least partly electric, especially since this technology is still a bit off.
I like the Free Piston Engine Linear Generator better since it's literally only one moving part (save for the myriad of pumps, valves and other assorted crap all engines have) and has a small size, but it will also be a stopgap measure on the road to pure electric.
And sure this might end up in a few specialized vehicles, but it won't revolutionize anything.

Valve has to add these to Portal 3.

Gaben can't save them. The 3 best VR people at Valve quit to work for them.
Game over.

One thing is certain... Numbers beyond 2 doesn't exist at Valve. Proof:

L4D1 & 2
Half-Life 1 & 2
Half-Life 2: Episode 1 & 2
Portal 1 & 2
TeamFortress 1 & 2

This might work on air, because you can compress air, but I'm pretty certain it won't work on water.

Water is not a marble. It's not even millions of marbles, though that might better illustrate how it would move through the 'valve'. In reality the water is going up all those side channels AND the central 'smooth' channel all at once. The back eddies from the side channels will serve to help guide the water flowing up the main tube and if you can get ANY suction out of that sucker at all I'd be amazed.

Like I say, air is more complex. It might work there, but the efficiency would be so low I can't ever see this replacing a standard pump.

Ah, so it becomes clear.

It's the air pressure created when puling an upward-pointing Tesla valve up that draws the water up and causes only little to travel back down when the pump is pushed down. It's not a full-on vacuum, but it would cause air and water in the tube to be drawn upward.

I wonder if that would work as well as they imply. I imagine it would take more effort to draw water than with the full vacuum of a traditional pump.

Why didn't they put that into one of their fancy CGI animations? This is the worst video ever. Now I want to down-vote it.

Thanks for helping lift the fog, @Payback.

The pump would still be there. It's just the two vavles that would be replaced. The actual piston would be (almost) the same in it's form and function.

So there would be no moving parts in the VALVES. The pump would still be a major, important moving part that would need to be serviced. But you are eliminating two points of very common failure with tesla's design.

If they were able to produce a prototype valve that was 5x to 10x the size of the one in the video, I might be interested in buying...

That is really really really cool. Videos do need audio though.

You're trying to replace the pump with the tubes, but you only replace the valves.

Replace the two flapper-style valves int the pump with two Tesla Tubes (tm) pointing up, and you'll see what you're missing. The plunger and arm are easy to design to be almost indestructible, it's the valves that wear out and/or break with great regularity.

The wear parts of the Tesla pump design are a couple o-rings and a bushing or two.

It's rather annoying that they make such a big point to state that this design of Tesla's is much better than a traditional hand pump and even go on to state all the problems with the hand pump, but then don't even hint at how exactly Tesla's design improves on any aspect of the hand pump.

It's just basic physics. If you want to pull water up a tube from a well in the ground, some kind of suction is required. The flappy caps provide both suction and a means to holding the rising water mid-valve while pumping. The Tesla thing could not replace or improve any of that functionality as far as I can imagine.

Even if it was to replace the entire length of valve, it wouldn't help water to come up any faster and it wouldn't prevent it from going back down. So what's the point?

*Request for comment. Someone enlighten me.

@lucky760 That's a question for an engineer or someone well-versed in fluid dynamics I'm guessing but something else in place to create the vacuum would probably suffice....something that wears-out with less frequency than the valve itself perhaps?

Nice, smart design.

I don't understand how it could be used in place of a valve with moving parts, such as the one they illustrated. The moving caps in the ground pump serve to create a vacuum to draw the water from the well up through the pump.

Tesla's valve makes it very hard for water to travel one direction, but the water's not going to climb up a valve at all without a vacuum.

Am I missing something?