Unfortunately I'm no expert on rotary engines. The following information is merely posted to help those interested in these engines. This is one type of engine which I have found is difficult to find information on.

Below are 4 diagrams showing the 4 strokes of a rotary engine. They are as follows: Intake: The intake stroke of a rotary starts when the leading edge of the rotor closes off the exhaust port and the vacuum in the chamber draws the air and fuel into the engine. Compression: The mixture of air and fuel is compressed when the leading edge approaches the two spark plugs. As the rotor continues to spin clockwise, the chamber's size decreases. Power: As the leading edge passes the spark plugs, they fire, thereby igniting the compressed air and fuel mixture. The released energy then pushes the leading edge towards the exhaust port. Exhaust: The exhaust stroke begins as the leading edge passes the bottom edge of the exhaust port. Here the trailing edge pushes the exhaust gasses out of the exhaust port. Now you must remember that there are two more edges of the rotor in different strokes of the cycle. While this exhaust stroke is happening, the next edge of the rotor is busy with it's intake stroke and the previous edge is busy with it's power stroke. This power stroke also helps the exhaust and intake stroke to be more powerful.

Below are the main engine moving parts of a rotary engine. As the two rotors (pistons) rotate around the eccentric (crank) shaft they make the shaft turn.

This photo shows a stock intake port on the right and a street port on the left. As you can the see the port on the left has been enlarged and polished for street applications.

This photo shows a stock exhaust port on the left. The port on the right has been enlarged for racing. This is one of the most cost efective modifications.

Porting on a rotary engine is similar to changing the camshafts of piston engines for high performance cams. A few mild to wild port porting possibilities are: Street port: This is the simplest and most common porting found on rotary engines. The intake and exhaust ports are just enlarged to increase power output. A good porting job combined with a decent performance intake and exhaust system will give a stock rotary engine an increase of about 50-60 percent. Nowhere else can you get such an improvement for so little work and money. Although fuel consumption is affected, a properly street-ported engine still has excellent drivability and low-end performance. Bridge port: When bridge porting you actually cut an additional intake port into the inside of the housing leaving some material between the new port and the original port on the surface of the housing. This "bridge" is left where the corner apex seal can pass over so that it doesn't fall into the new port. Underneath this bridge the new port is enlarged to the point where it joins up with the original port. This compromises low-speed driveability, emissions and fuel economy. The typical torque range is between 6,000 and 9,500 rpm. ½ Bridge port: A new port is cut, as above but the original port isn't opened up that far. This gives more power than street port but spreads it better than with a full bridge port with usbale power between 4,000 and 8,500 rpm. Peripheral port: This takes the intake ports out of the side housing and moves them to theperiphery of the engine in the rotor housing. The original ports are then filled with epoxy. This greatly alters port timing and and moves the power band way up. A street ported engine would produce power between 4,000 and 8,000 rpm where a peripheral ported engine is between 8,000 and 10000 rpm. This type of porting is reserved for all out racing engines as it creates overlap like a radical cam does in a piston engine. Here you can see an example of bridge porting.

Keeping your engine clean and cool is important. Changing oil at least every 5000 km's is a must, because the oil seems to accumulate more contaminants then with a piston engine. If you don't change the oil on time you could suffer from the symptoms in the following photo. It's likely that the apex seals cracked and got dislodged, taking a few turns around the combustion chambers where they were ground up damaging the rotor and housing in the process.