The Hirth 3202 and 3203 are a family of in-line twin cylinder, two stroke, carburetted aircraft engines, with optional fuel injection, designed for use on ultralight aircraft, especially two seat ultralight trainers, gyrocopters and small homebuilts. It is manufactured by Hirth of Germany.[1] [2]
The 3203 was developed as a replacement for the Hirth 2706 and as a competitor to the 640NaN0 Rotax 582. It replaced the 2706 in the Hirth line in May 2002. The engine is similar to the Rotax powerplant in being a two-cylinder in-line engine, with dual capacitor discharge ignition, although it is air-cooled, compared to the 582's liquid cooling. The 3202 was developed from the 3203 as a de-rated version to replace the Hirth 2704 and compete with the 500NaN0 Rotax 503. Both engines have the same bore, stroke, displacement, compression ratio, and weight as the Hirth engines they replace.
Both the 3202 and 3203 use free air or fan cooling, with dual Bing 34 mm slide carburetors or optionally fuel injection. The cylinder walls are electrochemically coated with Nikasil. Standard starting is recoil start with electric start as an option. The reduction drive system available is the G-50 gearbox, with reduction ratios of 2.16:1, 2.29:1, 2.59:1, 3.16:1, or 3.65:1, with a cog-belt reduction drive optional.
The engines run on a 50:1 pre-mix of unleaded 93 octane auto fuel and oil, or optionally oil injection.