Sunbeam 350HP
| Industry | Automotive |
|---|---|
| Founded | 1920 |
| Products | Automobiles, aero-engined cars |
The Sunbeam 350HP is an aero-engined car produced by the Sunbeam in 1920, distinguished as the inaugural vehicle among several land speed record contenders powered by aircraft engines.
Design
This automobile was equipped with a custom-designed 18.8-litre V12 engine that merged features from the Sunbeam Manitou and Sunbeam Arab aero powerplants. Its configuration consisted of four banks of three cylinders arranged in two rows set at a 60-degree angle, differing from the Arab’s 90-degree layout. Each cylinder incorporated one intake valve and two exhaust valves, all actuated by a single overhead camshaft. The engine utilized two camshafts driven through an intricate assembly of 16 gears connected to the front crankshaft, resembling the dual OHC system found on the Maori engine per cylinder bank. Initially, power was transmitted via a 4-speed gearbox to a rear axle fitted with a differential and driven by a shaft, replacing the dangerous chain drives common in other vehicles.
In 1920, Harry Hawker piloted the car at Brooklands but suffered a crash caused by tyre failure. Following this incident, the differential was substituted with a crown wheel and pinion setup that locked both rear wheels together, enhancing traction under the control of Kenelm Lee Guinness. The braking system was rudimentary, featuring a foot-operated brake acting on the transmission and a handbrake engaging rear drum brakes. Suspension comprised half-elliptic springs on all corners complemented by André Hartford friction dampers.
Racing career
The 350HP made its competitive debut at Brooklands in 1920 with Harry Hawker behind the wheel. Later that year in October, René Thomas established a record at the Gaillon hill climb.
On 17 April, Jean Chassagne claimed victory in the Brooklands Easter Meeting’s 13th Lighting Short handicap, averaging a lap speed of 114 mph. During May 1922, Kenelm Lee Guinness achieved three records: setting a new lap record at Brooklands, breaking the land speed record over one mile, and surpassing it again over one kilometre—marking the final land speed record recorded on the Brooklands circuit.
Blue Bird
Malcolm Campbell borrowed the vehicle for the Saltburn Speed Trials on 17 June 1922, where he surpassed his first speed record at . Despite this accomplishment, manual stopwatch timing prevented official recognition.
Campbell convinced Coatalen to sell him the Sunbeam, which he repainted blue and rechristened Blue Bird, becoming the fourth iteration of this name. On 23 June 1923 at Fanø, Denmark, he recorded a flying kilometre speed of . However, this too remained unofficial due to timing equipment limitations.
During the winter of 1923–1924, the car underwent aerodynamic refinement at aircraft manufacturer Boulton Paul in Norwich. Modifications included adding a slim radiator cowling, an elongated tapered tail section, and disk covers over the rear wheels. Additionally, new pistons increased engine compression.
Campbell returned to Fanø in summer 1924 but faced poor beach conditions and inadequate crowd control, resulting in tyre failures; one front tyre detached and tragically caused a fatality among spectators. Following this incident, Campbell protested against safety protocols and declined further attempts under those circumstances.
The car was then taken to Pendine Sands in South Wales where Campbell set his first of nine official records on 24 September 1924 by reaching 146.16 mph (235.23 km/h). Although he initially listed the vehicle for sale at £1,500, he retained it upon learning that J. G. Parry-Thomas intended to challenge with Babs. Returning to Pendine in 1925, Blue Bird raised the record to 150.766 mph (242.628 km/h) on 21 July—becoming the first automobile to exceed . The fastest mile covered reached , a figure later featured prominently in motoring advertisements for lubricants and spark plugs. To celebrate this milestone, Campbell commissioned scale models of Blue Bird.
Survival in the Present Day
Following Campbell’s involvement, the Sunbeam resumed participation in circuit racing, now equipped with broader tyres and a shortened tail, painted in green. Remarkably, as late as 1936, bandleader Billy Cotton achieved speeds exceeding one kilometre on Southport beach. The vehicle is believed to have stayed in Lancashire throughout World War II before its acquisition by the Beaulieu collection in 1958.
Today, the car is exhibited at the National Motor Museum located in Hampshire. After suffering significant engine damage during the 1990s, it underwent a thorough restoration and was operated for the first time in two decades in January 2014.
Restoration Efforts and 2015 Fundraising Campaign
During a test run in 1993, engine damage was uncovered due to a blocked oil passage that caused the engine to seize and "throw a rod." As a result, the vehicle was displayed with an evident hole in its engine casing.
In January 2014, after several years of detailed mechanical restoration carried out by the National Motor Museum’s workshop, the Sunbeam was publicly started for the first time in over half a century. It gained significant attention at events such as Rétromobile in Paris and was showcased at the Goodwood Festival of Speed.
In 2015, the National Motor Museum initiated a fundraising campaign aimed at producing a new gearbox for the Sunbeam 350HP. Manager and chief engineer Doug Hill highlighted:
Historically, the Sunbeam’s gearbox has been its vulnerable component. Post-WWII, the original gearbox was lost and substituted with one from an Albion 35hp van, which was engineered to handle just a fraction of this engine's power. This substitution negatively affected both performance and braking.
To return the car to its authentic 1925 condition and allow it to achieve its designed speeds, constructing a completely new gearbox from the ground up is essential—a complex task demanding our full technical expertise.
On 21 July 2015 at Pendine Sands, Wales, Don Wales—grandson of Sir Malcolm Campbell and himself a Land Speed Record holder—replicated Campbell’s inaugural world land speed record while driving the fully restored vehicle.
Regarding the appeal, Don Wales stated: "Doug Hill and his team have meticulously restored this magnificent car; it truly deserves the final components to complete its restoration!"
The new gearbox represents one element of an ongoing restoration project aimed at returning the vehicle to its original 1925 specifications. This includes manufacturing full-length exhaust systems, renewing seat upholstery, and recreating both the dropped nose cone and rear wheel spats.
In 2016, as part of its restoration appeal efforts, the National Motor Museum Trust was chosen as one of the beneficiary charities for the relaunched London Motor Show, where the Sunbeam 350HP was prominently displayed.
External links
- Record-breaking Pendine Sands – Sand Speed Wales (archived) – rare historical photographs
- Sunbeam and subsequent land speed record vehicles at Beaulieu – Flickr gallery
- National Motor Museum collection (archived) – documentation on the Sunbeam 350HP
- The Sunbeam 350HP Appeal – National Motor Museum updates
- Support the Sunbeam 350HP Appeal – National Motor Museum fundraising page