Improved Internal Combustion Engines: Zajac Motors

Seems awfully similar to the Scuderi engine.  Power density and packaging must suffer from the split combustion process, too.

This concept is basically a gas turbine with reciprocating compression and expansion stages instead of turbomachines. It seems likely to me that the only way to overcome the material limitations of the expansion cylinder is to downgrade the power density dramatically with respect to a conventional diesel engine. In which case it might achieve attractive efficiency in a stationary test, but if it has to haul its own weight around then the result could be different.
What was the power density (kW/kg) of the prototype?
PS. NOx formation does not decrease with combustion temperature, it increases.

They never said how efficient. seems like there wouldn’t be that big of an efficiency gain in a car for the same power range.

It certainly is a simplified system, therefore one would expect a more reliable one? As well as easier/cheaper to maintain. However, the high temp material (the ceramic you note) complicates the marketability of the idea.

In addition to the excellent points made by the other comments:  What about the rotary valves?  They have never achieved much market success because they have not been able to compete with poppet valves.
I seriously doubt the assertion that poppet valve trains consume 10% of an engines output.  Maybe it is so when the engine is idling and not producing any useful work, anyway.
One of the many advantages of poppet valves is their low power requirement which does not increase with increasing cylinder pressure, unlike rotary valves.

Sorry folks, this one is just an expensive experiment.  The VC’s have invested in “people” instead of “technology” again.  They have given up the best parts of the Otto cycle, which are the near constant volume combustion and high peak cycle pressures, as mentioned above, which reduces it to a brayton cycle with pistons, which has a much lower thermodynamic efficiency.  The slight increase in combustion efficiency can’t offset that.  The lower peak pressures will only increase heat transfer losses and reduce the effective expansion ratio - especially at part-load where 99% of fuel is consumed.  Similar problem in the Scuderi design.  The Scuderi folks haven’t published efficiency numbers even though they’ve spent millions!  The disadvantage of pistons machinery is that it has higher friction and heat losses at low pressures.  Since the specific power output is dramatically reduced due to the lower fuel-air ratio, the losses due to friction and heat will increase as a percentage of energy input.  Engine out hydrocarbon emissions should decrease, but carbon emissions will increase due to lower efficiency.  There are ways to achieve large gains in IC engines, but this isn’t it.

Tip Info / New Technology Submission - Gearturbine - Atypical

http://gearturbine.260mb.com

You Tube Video; Atypical New * GEARTURBINE / Retrodynamic = DextroRPM VS LevoInFlow + Ying Yang Thrust Way Type - Non Waste Looses

http://www.youtube.com/watch?v=0cPo9Lf44TE

GEARTURBINE -Atypical Combustion Turbine Engine, -State of the Art, -New Thermodynamic Technology, -With Retrodynamic “Dextrogiro vs Levogiro” Effect, is when the inflow direction moves is against [VS] of the circular rotary dynamic, When the inflow have more velocity the rotor have more RPM / because push the single turbine with the planetary gear, (an a example is like to move the head to the side of the strike hit) / RPM Rotor Move VS Inflow Conduits Way /ACTION VS REACTION / Front to Front / Velocity vs Velocity, making in a simple way a very strong concept of power thrust, a unique technical quality. -Wide cylindrical shape dynamic mass (continue Inertia cinetic positive tendens motion / all the motor weight is goin with the power thrust direction), -Non Waste, parasitic losses form-function engine system for; cooling, lubrication & combustion; -Lubrication & Combustion inside a conduit radial position, out way direction, activated by centrifugal force Fueled Injected (centripetal to in) , -Cooling in & out; In by Thermomix flow & Out by air Thermo transference, activated by the dynamic rotary move, -Increase the first compression by going of reduction of one big circumference fan blades going to, -2two very long distance captive compression inflow propulsion conduits (like a digestive system) (long interaction) in perfect equilibrium well balanced start were end like a snake bite his own tale, -Inside active rotor with 4 pairs of retrodynamic turbos (complete regeneration power system), -Mechanical direct “Planetary Gear” power thrust like a Ying Yang (very strong torque) (friendly loose friction) 2two small gears in polar position inside a bigger shell gear, wide out the rotor circumference were have much more lever power thrust, lower RPM in a simple way solution for turbines, to make possible for a some new work application (land). -3 Stages of inflow turbo compression before the combustion. -3 points united of power thrust; 1- Rocket Flames, 2-Planetary Gear & 3-Exhaust Propulsion, all in one system. -2two continuous circular moving inside combustion (rocket flames) like two dragons trying to bite the tail of the opposite other. -Hybrid flow system different kind of aerolasticity thermoplastic inflow propulsion types; single, action & reaction turbines applied in one same system, -Military benefits, No blade erosion by sand & very low heat target profile. -Power thrust by barr (tube); air sea land & generation application, -A pretender of very high % porcent efficient power plant engine. -Patent; Dic 1991 IMPI Mexico #197187