The Continental Tiara series are a family of air-cooled,

horizontally opposed A flat engine is a piston engine where the cylinders are located on either side of a central crankshaft. Flat engines are also known as horizontally opposed engines, however this is distinct from the less common opposed-piston engine design, wh ...

aircraft engine An aircraft engine, often referred to as an aero engine, is the power component of an aircraft propulsion system. Most aircraft engines are either piston engines or gas turbines, although a few have been rocket powered and in recent years ma ...

s. Designed and built by Continental Motors/TCM, the Tiara series were commercially unsuccessful, costing the company millions of dollars.

Design and development

Continental began development of the Tiara series in 1965.Leyes, p.119 At the time, CAE, Continental Motor's turbine engine subsidiary, had developed the T65, a small

turboshaft A turboshaft engine is a form of gas turbine that is optimized to produce shaftpower rather than jet thrust. In concept, turboshaft engines are very similar to turbojets, with additional turbine expansion to extract heat energy from the exhaust ...

engine which was being considered by

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for its new Model 206 helicopter. Faced with having to fund the production tooling for the T65 in order to keep the price reasonable, or funding the Tiara series, Continental's corporate management chose to invest in the Tiaras. While the Tiara series were basically traditional

boxer engine A flat engine is a piston engine where the cylinders are located on either side of a central crankshaft. Flat engines are also known as horizontally opposed engines, however this is distinct from the less common opposed-piston engine design, wh ...

s, they did have some unique features.Gunston, p.191 The engines had high rotational speeds, 0.5:1 gearing was used to reduce propeller speed, with the

camshaft A camshaft is a shaft that contains a row of pointed cams, in order to convert rotational motion to reciprocating motion. Camshafts are used in piston engines (to operate the intake and exhaust valves), mechanically controlled ignition systems ...

forming an extension of the propeller shaft.Continental, Teledyne Continental Motors, TCM (US); Rolls-Royce (UK) Part 1: Introduction and O-110 through OL-300
The propeller shaft featured the Hydra-Torque drive to reduce the shaft's vibrations. The engines were available with four, six- and eight-cylinders. All were fuel-injected, with turbocharging being optional. The engines' fuel consumption was high, which became a disadvantage during the

1973 oil crisis The 1973 oil crisis or first oil crisis began in October 1973 when the members of the Organization of Arab Petroleum Exporting Countries (OAPEC), led by Saudi Arabia, proclaimed an oil embargo. The embargo was targeted at nations that had su ...

era. In addition, the Tiaras' performance was not significantly improved over existing engines, making it difficult for aircraft manufacturers to justify the costs of certificating their products for the engines. These problems led Continental to finally discontinue the engines in 1980.

Series

Reference: Continental, Teledyne Continental Motors, TCM (US); Rolls-Royce (UK) Part 1: Introduction and O-110 through OL-300

Four-cylinder

;Tiara 4-180 (O-270) :180 hp, 271 cu in capacity

Six-cylinder

;Tiara 6-260 (O-405) :260 hp, 406 cu in capacity ;Tiara 6-260A ;Tiara 6-285 (O-405) :285 hp, 406 cu in capacity ;Tiara 6-285A: ;Tiara 6-320 (O-405) :300 hp, 406 cu in capacity ;Tiara T6-260 (O-405) :260 hp, 406 cu in capacity, turbocharged ;Tiara T6-285 (O-405) :285 hp, 406 cu in capacity, turbocharged ;Tiara T6-320 (O-405) :300 hp, 406 cu in capacity, turbocharged

Eight-cylinder

;Tiara 8-380 (O-540) :380 hp, 541 cu in ;Tiara T8-450 (O-540) :450 hp, 541 cu in, turbocharged

Applications

Tiara 6

* Cerva CE.44 Couguar * Cierva CR.640 (not built) * Piper PA-36-285 Pawnee Brave * Robin HR100/285TR Tiara * Spencer S-12-EAir Car (prototype) * Transavia PL-12 T-320 Airtruk *

Trident Trigull The Trident TR-1 Trigull is a Canadian amphibious aircraft that was developed by Trident Aircraft of Burnaby, British Columbia and later Sidney, British Columbia. The aircraft was intended to be supplied as a complete ready-to-fly certified a ...

(prototypes)

Specifications (Tiara 6-285-A)

References

* * *

External links

Teledyne Continental Motors

* ttp://www.flightglobal.com/pdfarchive/view/1974/1974%20-%200954.html World Aero-engine industry, Flight International, 20 June 1974 {{DEFAULTSORT:Continental Tiara Series 1960s aircraft piston engines

Tiara A tiara (from la, tiara, from grc, τιάρα) is a jeweled head ornament. Its origins date back to ancient Greece and Rome. In the late 18th century, the tiara came into fashion in Europe as a prestigious piece of jewelry to be worn by women ...