The Bristol Titan was a British five-cylinder air-cooled radial engine, designed and built by the Bristol Aeroplane Company in the late 1920s. It had the same size cylinders as the earlier Bristol Mercury engine, 5.75 in × 6.5 in (146 mm × 165 mm) (displacing 844 cu in (13.83 L)), and produced between 200–240 hp (150–180 kW). Later versions of the Bristol Titan also used a Farman-style reduction gear produced by Gnome-Rhône.

The Bristol Titan
Type Piston aero engine
Manufacturer Bristol Aeroplane Company
Designer Roy Fedden
First run c.1928
Major applications Avro 504N
Bristol Primary Trainer
Developed into Bristol Neptune

Design and development


The engine was designed as a five-cylinder radial, to use as many parts of the Bristol Jupiter as possible. Cylinders, pistons, articulated connecting rods, crankshaft and other minor parts were interchangeable with the Jupiter.[1]

The major significance of the Titan was that it was licensed to Gnome-Rhône and became the pattern for the Gnome-Rhône 5B and 5K. In 1927 Gnome-Rhône was looking for ways out of its licence agreement with Bristol for the Jupiter engine of 1920 and began to produce the Gnome-Rhône 5B and 5K without royalties.

Gnome-Rhône was not satisfied with simply producing Bristol designs under licence, and started a major design effort based around the mechanics of the Titan engine. The results were introduced in 1927 as the K-series, spanning the 260 hp (190 kW) Gnome-Rhône 5K Titan, the seven-cylinder 370 hp (280 kW) Gnome-Rhône 7K Titan Major, and the nine-cylinder 550 hp (410 kW) Gnome-Rhône 9K Mistral. With the introduction of the K-series, Gnome-Rhône finally ended royalty payments to Bristol, the Gnome-Rhône 5K being built in much greater numbers than the original Bristol Titan. By 1930 they had delivered 6,000 Jupiters, Mistrals and Titans, making them the largest engine company in France.


Titan I
(1928) - 205 hp (153 kW)
Titan IIF
Modified valve gear.
Titan II (Special)
Titan IV
(1928) - 205 hp (153 kW), 0.5:1 reduction gear from Bristol Jupiter.
Gnome et Rhône 5B
Gnome et Rhône 5Ba
Gnome et Rhône 5Bc
Gnome et Rhône 5K Titan
licence-built Titan II, 230 hp (170 kW)
Gnome et Rhône 7K Titan Major
enlarged seven-cylinder Titan with many detail improvements, produced by Gnome-Rhône without licence.



Specifications (Titan I)


Data from Lumsden.[2]

General characteristics


  • Valvetrain: Overhead valve, 4 valves per cylinder
  • Cooling system: Air-cooled
  • Reduction gear: None, direct drive, left hand tractor


See also


Related development

Comparable engines

Related lists




  1. ^ Flight International 5 July 1928
  2. ^ Lumsden 2003, p.102.


  • Lumsden, Alec. British Piston Engines and their Aircraft. Marlborough, Wiltshire: Airlife Publishing, 2003. ISBN 1-85310-294-6.