The Zoche aero-diesels are a trio of radical German prototype diesel radial aero-engines intended for light aircraft, designed by Michael and Georg Zoche in the 1990s.[1] Zoche aero-diesels are modular piston engines and are all direct-drive, air-cooled, radial two-stroke diesels with up to four cylinders per row. They all feature direct fuel-injection, two-stage charging (turbocharger and supercharger), and intercooling. In each plane (or row), all the pistons connect to a single throw on the crankshaft.

Zoche ZO series
Type "Cross-8" radial aero-engine
National origin Germany
Manufacturer Zoche

The testing and gestation period of the Zoche engines has already lasted over 25 years; and whether or when production may eventually start is unknown. However, in 2019, Georg Zoche posted this message online: "Don't worry and remain patient; we are working on it".[2]

Design and development

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The range comprises three radial engines, namely: a "cross-4"; a twin-row "cross-8"; and a V-twin.[3] As yet, there are no plans for a 3-cylinder version.

The AOPA website explains the "cross-4" ZO 01A as follows: "The radial design was chosen for its ability to be effectively air-cooled and 100% balanced at all rpm with a simple counterweight system. All four connecting rods are attached to a single crankshaft throw. This prevents any crankshaft twisting, which is hard to balance out in opposed-configuration engines. Zoche engines use a pneumatic starting system that does away with the need for a heavy-duty starter and battery system".[4] Propeller rotation is clockwise (viewed from the cockpit). Engine mountings are attached to the cylinder heads. Engines are to be certified to JAR-E and FAR 33, and a TBO of 2,000 hours is anticipated.

The founder of the project is Michael Zoche, who claims that the ZO engines will have the following advantages:

  • they will be lightweight, compact (with low frontal area) and very smooth;
  • low fuel consumption; high power-to-weight ratio;
  • the lubrication system will allow aerobatics;
  • diesel fuel injection, so no carburetor icing;
  • direct-driven generator, so no drive belts;
  • good reliability through a low part count and absence of poppet valves;
  • pneumatic starting obviates both electric starter motor and heavy starter battery;
  • complete absence of rubber hoses; cheaper parts through modularity;
  • reduced fire risk compared to avgas;[5]
  • good power output, even at altitudes up to 9,000 feet (3,000 m).[3]
  • the engines will also have a "classic radial" appearance that is appropriate for some aircraft types.

A Zoche engine has run effectively in wind tunnel tests,[6] but Zoche seem barely any closer to production than they were a in 2010. Experimental engine manufacturers seem to experience difficulties in proceeding beyond the prototype stage. The cited engine weights include: starter-generator, hydraulic propeller-governor, turbocharger and supercharger, and oil- and fuel-filters.

Zoche engine variants

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ZO 01A
Single-row cross-4, 2,660 cc (162 cu in), (max) 150 hp (112 kW) @ 2500 rpm, 84 kg (185 lb)), fuel consumption 21 litres/h @ 75% power.[3]
ZO 02A
Double-row cross-8, 5,330 cc (325 cu in), (max) 300 hp (224 kW) @ 2500 rpm, 123 kg (271 lb)), fuel consumption 42 litres/h @ 75% power.[3]
ZO 03A
V-twin, 1,330 cc (81 cu in), (max) 70 hp (52 kW) @ 2500 rpm, 55 kg (121 lb)), fuel consumption 10 litres/h @ 75% power.[3]
ZO 04A
A 2,000 hp (1,500 kW) compound diesel engine for use in the Sentinel 5000 airship on vectoring mounts.[7]

A consequence of the modular design, with all engines sharing parts (such as an intercooler), is that the larger engines have a much higher power to weight ratio than the smaller engines, as follows:

  • The 8 cylinder ZO 01A claims 2.43 bhp per kilogram;
  • The 4 cylinder ZO 02A claims 1.78 bhp per kilogram;
  • The 2 cylinder ZO 03A claims 1.27 bhp per kilogram.

Lambert Mission

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The Lambert Mission 212,[8] a kit-built 4-seat aircraft from Belgium, was initially designed around the Zoche ZO1A engine; but, with the non-appearance of the Zoche, Lambert were obliged to select other engines, the DeltaHawk® DH200A4 (or DH180A4), or the XP-360 engine.[8] In May 2010 the second M212 Mission (and first kit-built example) was successfully flown.

See also

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Comparable engines

Related lists

References

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  1. ^ "Home". zoche.de.
  2. ^ "Zoche aero-diesel running on wind tunnel test bench" – via www.youtube.com.
  3. ^ a b c d e ZOCHE aero-diesel brochure
  4. ^ "Horsepower of a Different Color". Archived from the original on January 8, 2007. Retrieved July 31, 2012.
  5. ^ Brochure claim: "High inflight reliability – no carburetor-icing, no magneto or spark- plug problems, no vapor lock. Turbine inlet temperature is so low that it needs no monitoring. Even cylinder head temperatures are not critical.
  6. ^ "zoche aero-diesels testbench video". www.zoche.de.
  7. ^ Gunston, Bill (2006). World encyclopedia of aero engines : from the pioneers to the present day (5th ed.). Stroud: Sutton. p. 254. ISBN 9780750944793.
  8. ^ a b "Lambert Aircraft".
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Patents: