Sunbeam Matabele

The Sunbeam Matabele was the last development of one of Sunbeam's most successful aero-engines, the Cossack.

Design and development

The Cossack was a twin overhead camshaft V12, with 4 valves per cylinder. The Matabele fitted this with two of the blocks from the Saracen, cite book
title=World Encyclopaedia of Aero Engines
last=Gunston |first=Bill
publisher=Patrick Stephens
date=1986] using aluminium instead of the Cossack's cast iron. The Saracen's bore was slightly larger at 122 mm (from the Cossack's 110 mm) and with the same stroke of 160 mm this gave a capacity of 22.45 litres. Ignition was by four magnetos (two per bank), with twin sparkplugs. A propeller reduction gear of 1.63:1 was fitted. cite web
title=The Matabele
url=http://www.localhistory.scit.wlv.ac.uk/Museum/Transport/planes/SunbeamEngines9.htm
publisher=Wolverhampton Museum of Industry]

Matabele II

A simplified engine was developed for non-aircraft use. This avoided the propellor reduction gearbox and had a single magneto per bank, rather than the duplicated magneto and sparkplug systems usual in aircraft for reliability. This engine was aimed at the developing market for racing powerboats.

Use

The Matabele was tested successfully in a DH.4 from May 1918. Although the tests went well, no other aircraft had one installed, either for production or even for testing.

Sunbeam 1000HP

The Matabele engine is best known today for having powered the Sunbeam 1000HP land speed record car, the first car to exceed 200 mph.

After taking the land speed record at 152.33 mph with the Sunbeam Tiger, Segrave realised that his small, lightweight racing car would be inadequate to hold the record against the aero-engined leviathans now appearing in the contest. The Sunbeam-Talbot-Darracq team was short of funds and so little new development was possible.

A pair of Matabele engines were found in the Sunbeam works at Wolverhampton, previously from a powerboat. As the Sunbeam 1000HP is reported as having 4 magnetos per engineNational Motor Museum guidebook, Beaulieu] , these would appear to be Matabele I, rather than Matabele II.Fact|date=May 2008

On 29 March 1927, the Sunbeam became the first car to exceed 200 mph. Although loudly trumpeted as the "1000 HP" Sunbeam, the actual power was somewhere around 900 bhp.

The installation of these engines was somewhat unorthodox, necessitated by the limited funds for new work. The rear engine was started first by compressed air, then the front engine was started through a mechanical friction clutch. Once synchronised, they were locked together with a dog clutch for the record attempt. The car's last run was a demonstration circuit at Brooklands, running at slow speed on only one engine, with this dog clutch disconnected.

Specifications

pistonspecs
designer=Louis Coatalen
reduction_gear=1.63:1
type=12-cylinder naturally-aspirated liquid-cooled "Vee" piston aircraft engine
bore=122 mm
stroke=160 mm
displacement=22.444 litre
length=
diameter=
width=
height=
weight=1,091 lb (495 kg) wet
valvetrain=Twin overhead camshaft, twin intake and twin exhaust valve per cylinder
supercharger=
turbocharger=
fuelsystem=Two Claudel-Hobson HC.7 carburettors
fueltype=
oilsystem=
coolingsystem=water
power=400 hp (300 kW) at 2,000 rpm

specpower=13.4 kW/litre
compression=
fuelcon=
specfuelcon=
oilcon=
power/weight=

References