Napier Sea Lion Engine
|1919||Height Record of 30,500 feet.|
|1929||Land Speed Record at 231.3 miles per hour.|
|1929||Air Speed Record at 336.3 miles per hour.|
|1930||Water Speed Record at 100.13 miles per hour.|
|1931||Land Speed Record at 246.1 miles per hour.|
|1932||Land Speed Record at 253.968 miles per hour.|
|1933||Air long Distance Record at 5,309 miles.|
|1939||Land Speed Record at 369.74 miles per hour.|
|1947||Land Speed Record at 394.196 miles per hour.|
Names such as Campbell, Seagrave and Cobb are prominent as the record setters in the above list.
The air racing history includes the Schneider Trophy races : 1922. Held at Naples, Italy. 1st place in a Supermarine Sea Lion II with a 456hp Napier Lion engine at a speed of 145.7 mph (234.48 km/h). 1923. Held at Cowes, Isle of Wight. 3rd Place, a Supermarine Sea Lion III with a 525hp Napier Lion III. 1925. Held at Baltimore, Md., USA. 2nd place in a Gloster III, Napier Lion VII of 670hp, a speed of 225mph (362km/h). 1927. Held over the Solent. 1st and 2nd places, Supermarine S5 with a 874hp Napier Lion VIIB engine at a speed of 281.68 mph (453.22 km/h). 1929. Held over the Solent. 3rd place, a Supermarine S5 with a 874hp Napier Lion VIIB engine at a speed of 282.15 mph (454.02 km/h).
A total of at least 9 race starters were powered by Lion engines from 1919 to 1929 when Rolls Royce finally eclipsed the Lion, this was RR's only competitive win as in '31 there were no other entries due to pre race tragedies (by contrast, in 1924 the competition had withdrawn after the British entry crashed).
The "Sea Lion" was intended for maritime use in high performance boats and it might seem odd that the museum is refurbishing this version of the Lion. There is actually one use that makes it very appropriate that it is being restored by an aviation museum. This engine was used in the type 100 High Speed Launches designed by the British Powerboat Company which were fast long range offshore rescue craft. Each 64 foot long launch used three of these engines to deliver 1500 hp and obtain a speed of 45 mph, a good performance even today. One of these launches, HSL 102, has been restored by the British Military Powerboat Trust (Marchwood, Southampton). In the month of June 1941 alone, this one boat rescued 38 RAF airmen.
With such a long and varied life the engine cannot be represented by one simple set of data. The following figures are a reasonable summary however:
Type: W12 spark ignition natural aspirated 4-stroke piston engine
Cylinders: 3 in 60° angle rows
Valve arrangement: 4 poppet valve in each cylinder
Bore and stroke: 5.5 x 5.125 in
Swept volume: 1461 cu in ( 23.9 litre)
Compressions ratio: 5.5:1 to 10:1 on racing engines
Max revolution: 2200
HP range: 468 - 1320
Weight, lbs: 930
The APSS is a registered charity
in Scotland, charity No. SC033307
A member of the British Aviation Preservation Council