Hirth 2702 Explained

The Hirth 2702 and 2703 are a family of in-line twin cylinder, two stroke, carburetted aircraft engines designed for use on ultralight aircraft and especially two seat ultralight trainers, single seat gyrocopters, and small homebuilts. It is manufactured by Hirth of Germany.[1] [2] [3] [4]

Development

The 2703 was developed as a competitor to the 500NaN0 Rotax 503 and is similar to the Rotax powerplant in being a two-cylinder in-line engine, with dual capacitor discharge ignition. The 2702 was developed from the 2703 as a de-rated version.

Both the 2702 and 2703 use free air or fan cooling, with Bing 34mm slide carburetors. The cylinder walls are electrochemically coated with Nikasil. Standard starting is recoil start. Reduction drive systems available are the G-50 gearbox with reduction ratios of 2.16:1, 2.29:1, 2.59:1, 3.16:1, or 3.65:1, or a multi-element cog belt drive. A tuned exhaust and electric start are optional.

The engines runs on a 50:1 pre-mix of unleaded 93 octane auto fuel and oil.

Variants

2702
  • Twin-cylinder in-line, two stroke, aircraft engine with a single Bing 34mm slide carburetor. Produces 400NaN0 at 5500 rpm and has a factory rated TBO of 1200 hours. Still in production.
    2703
  • Twin-cylinder in-line, two stroke, aircraft engine with dual or optionally a single Bing 34mm slide carburetor. Produces 550NaN0 at 6200 rpm and has a factory rated TBO of 1000 hours. The 2703 has been largely supplanted in production by the Hirth 3202, but in 2009 was still available as a special order from the factory.

    Applications

    2702
    2703

    External links

    Notes and References

    1. Cliche, Andre: Ultralight Aircraft Shopper's Guide 8th Edition, page G-3 Cybair Limited Publishing, 2001.
    2. Web site: 2702 2 cycle 40hp. 2009-12-17. Recreational Power Engineering. n.d.. https://web.archive.org/web/20090919163822/http://www.recpower.com/2702.htm. 2009-09-19. dead.
    3. Web site: 2703 2 cycle 55hp . 17 January 2013. Recreational Power Engineering . n.d. . https://web.archive.org/web/20100302191141/http://www.recpower.com/2703.htm . 2 March 2010.
    4. Purdy, Don: AeroCrafter - Homebuilt Aircraft Sourcebook, page 72. BAI Communications.

    This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "Hirth 2702".

    Except where otherwise indicated, Everything.Explained.Today is © Copyright 2009-2024, A B Cryer, All Rights Reserved. Cookie policy.