thermal expansion", fully adjustable "non-rigid" (flexible) THERMAL-DYNAMIC SEMISLEEVES^TM  to ENHANCE full speed and idle rpm performance, and THERMAL-DYNAMIC EXHAUST BAFFLES^TM to provide highest back pressure/heat retention for OPTIMUM idle rpm, fuel vaporization, and sound deadening. 

(3)   BASIC MECHANICS: On full throttle THERMAL-DYNAMIC SEMISLEEVES™ automatically expand, with a rise in engine temperature, to boost SEMISLEEVE EXHAUST ("BLOWBY")⁽¹⁾ and SUB-PISTON INDUCTION⁽²⁾ for a super high top-end RPM and, on idle, automatically contract, with a fall in engine temperature, to restrict SEMISLEEVE EXHAUST and SUB-PISTON INDUCTION.  When the semisleeves contract (shrink) and, thereby, tighten over the cylinder's exhaust ports, they produce TERRIFIC BACK-PRESSUE/HEAT RETENTION, which keeps the glow plug hot and the flame lit for a super low "park-on-runway" idle!  (NOTE: "idle" tests were done with a 3½ oz. test bed with tricycle landing gears - no drag on wheels!)

⁽¹⁾ Semisleeve exhaust ("blowby"): The engine's exhaust that   escapes under the semisleeves.

⁽²⁾ Sub-piston induction (free porting): Intake of oxygen rich air through the engine's exhaust ports and under the piston skirt.

2. THERMAL-DYNAMIC SEMISLEEVES™ float on a cushion of high pressure exhaust waves (up to 500/second!) to reduce semisleeve/cylinder friction/wear, throttle servo load, and battery drain.  The latest model PET™ can be operated easily with the lowest torque servos weighing less than two (2) grams!

3. THERMAL-DYNAMIC EXHAUST BAFFLES™: The THERMAL-DYNAMIC EXHAUST BAFFLES™ are the SECTIONS of the THERMAL-DYNAMIC SEMISLEEVES™, between the WING DOUBLER LEGS™, that cover or partially cover the cylinder's exhaust ports.  The EXHAUST BAFFLES are fully adjustable and variable in size.  On full throttle/full speed the EXHAUST BAFFLES cover approximately 80% of the cylinder's exhaust ports.  As the PET™ rotates from the full speed throttle position to the idle throttle position, the semisleeves progressively cover more of the cylinder's exhaust ports, effectively increasing the size or area of the EXHAUST BAFFLES, which progressively increases the deadening of the engine's sound.