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Technology Stocks : Advanced Engine Technologies (AENG) -- Ignore unavailable to you. Want to Upgrade?

To: wonk who wrote (304)	5/27/1998 5:04:00 AM
From: 246810	Respond to of 3383

Welcome 4th or 5th technical analyst, now we are back ON TOPIC. You have hit several nails on the head and expressed it in layman's terms for all to heed. Sword, shash and I tried, but maybe failed in being too technical. Maybe Greg can now come down to earth and get off this short seller vindetta (why did he start?) long enough to answer your questions. Good post. 246810

To: wonk who wrote (304)	5/27/1998 1:11:00 PM
From: shashyazhi	Read Replies (3) \| Respond to of 3383

I find the OX2 engine to be a very interesting piece of engineering. I am sure that it has many possibilities. But comparing a 66.25 cubic inch 8-cylinder engine to a 350 cubic inch 8-cylinder engine becomes a little misleading, when you consider that the OX2 engine fires 16 times per revolution, and the Chevy engine fires 4 times per revolution. It takes TWO full turns of the Chevy crankshaft to fire all 8 cylinders! If you multiply 66.25 times 4, you get 265 cubic inches, which is the actually effective displacement of the OX2, per revolution of the output shaft. And if you divide 350 by 2, you get 175 cubic inches for the Chevy engine, per revolution of the crankshaft. So, by comparison, the "little" OX2 engine displaces more air per minute than the Chevy V-8. But it has to run like Speedy Gonzalez (mouse in Warner Brothers cartoon?) in order to accomplish this feat. The cam plate in the output end of the engine causes the pistons to move back and forth at a furious rate. 2500 RPM in an engine of this design is equivalent to 10,000 RPM in a conventional engine. Only motorcycle engines, Formula I and Indy car engines ordinarily run at these very high speeds. If the 74 millimeter stroke figure is accurate, the stroke is nearly 3 inches, which is quite long for an engine of this size. This long stroke means that the engine is running at a piston speed of 4905 feet per minute. Again, only racing engines regularly reach piston speeds over 4500 feet per minute. The formula for mean piston speed is c = .166 X L X N, where L is the length of the stroke in inches, and N is the crankshaft speed, in revolutions per minute. We can see that the Chevy 350 is loafing along at 2614.5 feet per minute when it is turning 4500 RPM with it's 3.5 inch stroke. But the OX2 engine is running at the equivalent of 10,000 RPM, with a 2.955 inch stroke. Another problem that this engine gets into, is the limited amount of time for cylinder filling and exhausting. Since the engine fires so many times per minute, no system of poppet valves could possibly operate fast enough. So this engine has some sort of port arrangement similar to a two-stroke engine. In other words, at regular intervals, a hole lines up with each cylinder, and, depending on whether the piston is on the intake or exhaust stroke, air flows into the cylinder, or exhaust flows out of the cylinder. And the arrangement of the engine would indicate that the exhaust port is right next to the intake port. At some point, there is overlap, with both ports unavoidably lined up to the rotating cylinder at the same time. The simplified formula for the time allowed to fill the cylinder is T= Y divided by ( N X 6 ), where T is time in seconds, Y is the port duration in degrees, and N is the output shaft speed in revolutions per minute. If we divide the 360 degree circle of the engine end plate by 8, we can see that there is a maximum possible exhaust port duration of only 45 degrees. The exhaust port duration has only a maximum time of .003 seconds to empty the cylinder in preparation for the next intake stroke while the output shaft is turning 2500 RPM. That's only three-thousandths of a second! Ordinary two stroke engines have up to 180 degrees of duration and have .004 seconds to scavenge the cylinder while turning 7500 RPM. The fact that the port can be almost as large as the cylinder bore has been mentioned. I would submit that, due to the limited amount of time for cylinder exhausting, the port MUST be very large. What this translates into, is an engine which becomes somewhat asthmatic as the engine speed increases; it simply runs out of breath! This explains why torque will begin to drop off rapidly as the engine RPM increases. It works the same way in any engine, OX2 or Chevy V-8. All mechanical devices have certain built-in mechanical advantages and disadvantages. The engineer works with compromises to achieve the goals of superior performance and learns to accept the limitations of the physical principles involved. What looks like an elegant concept often runs right into the brick wall of reality. I would love to know more about how the OX2 inventor has avoided this collision in the intake system. Good luck to all with your investment.