Take a look at the Pattakon PRE engine at http://www.pattakon.com/pre/index.html



it provides some 30 to 40% more time (piston dwell near TDC) to the fuel to get prepared and burned efficiently:



Here is a single cylinder 4stroke PRE



and here is the Junkers-PRE version



which is absolutely balanced, has 4stroke lubrication, has built-in scavenging pumps and trough scavenging, has more than 2stroke power concentration and top thermal efficiency.

Need your comments and objections.

Thanks
Manolis Pattakos

 

such design is very similar to marine engines use by ships.

more moving parts i think is more parts to likely get wear out.

 

If you mean the conventional Junkers engine, it is different: it offers as much time for combustion as the conventional engine (i.e. 30 to 40% less than PRE).




As for the moving parts, the single cylinder Junkers-PRE has one power pulse per crank rotation, it is also absolutely balanced and has improved thermal efficiency (the constant volume portion of combustion is significantly increased).
Count the moving parts of the single cylinder Junkers-PRE.
Then count the moving parts of the Yamaha TDM below (forget the cylinder head). The TDM is balanced only as regards its 1st order inertia forces and has also one power pulse per crank rotation.


Do you still think there are more moving parts in PRE?

Thanks
Manolis Pattakos

 

just the head of the piston against the body. was it fixed?

so the engine is designed as high speed rather than delivering more power? on long stroke version, it seems to have more frictional surface.

will the electric power design create a gyroscope effect at a certain speed?

the design is so interesting that i want to make a working model. does it need a counter balancing shaft?

was it patented? do i need permission to produce them?

very interesting indeed.

 

Sleepwalker,

The piston moves as a single piece.
It can be a single piece, but not necessarily. For instance, it is common practice to have, in a Direct injection Diesel, steel cylinder head.

As long as the breathing of the engine is efficient at high revs, the high speed revving and the more power are the same thing. Be more specific.

Talking for long stroke PRE: The “frictional surface” is defined during design. I.e. the surface of the piston that is in touch to the cylinder can be as small as you like (but below some limit the lubricant “brakes” and the piston comes in direct contact to the cylinder wall). Instead of seeing the total piston surface that could come in “touch” to the cylinder wall, it is more correct to see the thrust loads from combustion and inertia.

For the gyroscopic effect of the electric power plant : look at the Hybrid car diagram at the bottom of the http://www.pattakon.com/pre/index.html . The two electric generators are horizontally located. This way there is no gyroscopic effect on the vehicle, i.e. the vehicle changes direction (i.e. turns around the corners) as easily as without having the power plant in operation.

The Junkers-PRE does not need a balancing shaft. It is absolutely balanced as is. Think simply: the two pistons move symmetrically, so the two pistons center of gravity is always at the center of the engine.

The PRE engine is patent pending. You do not need permission to make and test some prototypes.

Thanks
Manolis Pattakos