Racing Beat Intake Port Templates allows you to undertake your own "street" intake porting effort on most 12A or 13B engines (except 13B 6-port and Renesis). Rotary tuners long ago discovered that changes to the intake port shape will alter intake timing, allowing increased airflow and velocity improvements. These templates are traced from Racing Beat's own master templates, which are the result of years of research and development. The actual port shapes are traced onto thin sheets of aluminum which you must first cut out, testing your ability to use a die grinder effectively before attempting to port an expensive engine component. The finished Racing Beat porting template is held in place and the porting shape is then traced onto each housing. You must then use your own judgment to develop the port shape within and beyond the scribed line.
Over the years the hand-grinding art of intake porting and has evolved into what has now become accepted practices and established guidelines. Almost every conceivable porting attempt has been tried, while most providing outstanding results and others producing expensive disappointments. Porting efforts can range from a mild "street" modification to more extreme efforts best suited for high RPM racing applications. Intake porting can provide outstanding performance benefits when combined with appropriate intake and exhaust upgrades, but as the porting effort becomes more advanced the need for more comprehensive knowledge of rotary engine performance and tuning is required to successfully integrate all aspects of the rebuild project. If you're new to rotary engine tuning, or considering your first intake porting effort we strongly suggest you educate yourself about the pros and cons of the porting effort. Racing Beat offers an excellent source of information for both intake and exhaust porting in printed form, STREET ROTARY. This comprehensive book dedicates an entire chapter to the subject of engine porting and is an excellent resource guide for complementary upgrades for your engine project.
An Example of Intake Porting
As seen in the photo illustration below, a typical porting effort can be viewed "before and after". Take note of the differences in the overall size, depth and width of this porting effort as compared with the stock port. Also note the thickness of the stock casting in the area below the porting effort, an over-aggressive and deep porting effort can break through to the underlying water jacket area of the housing - resulting in a expensive failure! In many cases the depth of the porting effort is "by feel" and/or prior experience of the porting technical or tuner.