13B Rotary Engine Exhaust Street Port Template

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This is a simple exhaust port template that I made for my 13B-REW engine. I didn't want to spend $40 for a similar template, so I researched port shapes and designed my own port in CAD. This mimics similar medium-sized street ports that many people use for turbo engines. My philosophy with this design: - Basically no material removal upwards that would add to the intake/exhaust overlap already present in the stock engine. Overlap is typically viewed as bad for turbo engines. - Around 3mm of material removal downwards with a rounded shape. This opens the exhaust port more gradually and earlier. Helps spool the turbo better and promotes more linear expansion of the exhaust gasses with the gradual opening. - Sides opened up 1mm overall but more squared instead of rounded. This just maximizes the area of the port and allows you to match the housing to the exhaust sleeve. How to use it: - Print both the stock port template and the street port template - Line up the stock port template with the stock exhaust port. Mark the top edge of the template on the rotor housing. - Now take the street port template and line up the top with the mark you made on the rotor housing. (arrow faces up) - Mark the port shape with a marker - Start grinding (I used a carbide burr on a dremel)