Perkins Producc 1.6-litre Vehick Oil Engine
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THE smallest four-cylindered oil engine to go into quantity production for light commercial vehicles and cars is announced today by F. Perkins, Ltd., Peterborough. It is known as the Four 99 and is similar in most respects to the small unit announced by Perkins at the Smithfield Show last year.
Over five years' development work has gone into it. The principal aims have been to obtain . a quiet, smooth-running engine, compact enough to be used as a replacement unit in most light vans and medium-sized private cars, whilst still providing at least 50 per cent. greater fuel economy.
It is an indirect-injection unit embodying a new form 9f combustion chamber covered by British Patent 559,755. A bore of 76.2 mm. (3 in.) and stroke of 88.9 mm. (3.5 in.) give a capacity of 1.621 litres (99 Cu. in.). The nominal compression ratio is 20 to 1.
The version offered for commercial vehicles has a maximum governed speed of 3,600 r.p.m., at which the gross and net power ratings are 42.3 b.h.p. and 40.5 b.h.p. respectively. The car engine has a higher governed speed-4,000 r.p.m.and 43 gross b.h.p. is developed, the net rating being 40.5 b.h.p. Gross and net torque outputs of both versions are the same-73 lb.-ft., and 71 lb.-ft. respectively, these peaks occurring at 2,250 r.p.m.
An industrial version is also offered. This is available with either hydraulic or mechanical injection-pump governors and its " normal-conditions " rating is 32 b.h.p. at 3,000 r.p.m., whilst its maximum intermittent rating is 35 b.h.p. at the same governed speed. The maximum torque output at 2,000 r.p.m. is 60 lb.-ft.
The new unit has an overall length, less flywheel, of 22 19/32 in., whilst its overall height, less air cleaner, is 294 in. The maximum width is 19* in. and it weighs 361 lb. without a flywheel.
Conversion kits are being offered for the 1955-56 Bedford CA 10-12-cwt. vans and the various applications of this chassis, and the Austin and Morris 15-cwt.. vans, pick-ups and passenger vehicles. Conversion kits are also pending for other vehicles, such as the Thames 12-15-cwt. van.
Special kits are available for the current Ford Consul and earlier versions of the Vauxhall Velox and Wyvern, whilst the unit has been successfully applied to
the Austin A70 pick-up, the Standard. 12-cwt. van, the Trojan personnel carrier, various Renault, Simca and Opel vehicles and the Beardmore Mark 7 taxi.
The engine costs £176 5s. and complete conversion kits are available at prices ranging from £207 10s. to £235 12s. 6d. These prices do not include heavy-duty batteries or labour charges.
A one-piece cast-iron cylinder block and crankcase is employed, with centrifugally cast-iron wet liners, flanged at their upper ends and sealed at the lower ends by synthetic-rubber rings.
The forged crankshaft is of chrome. molybdenum steel and the three main bearings are lead-bronze-lined, steelbacked pre-finished units. Similar riaaterial is used for the big-end bearings, and the high-tensile steel connecting rods have lead-bronze, steel-backed, wrapped little-end bushes.
High-silicon aluminium-alloy pistons are ernployed. Each pion has three compression rings and one scraper ring above the gudgeon pin and one scraper ring below it. The top compression cing is chromium-plated and the gudgeon pins are fully floating.
Valve Arrangement
The high-duty cast-iron camshaft is carried low on the right-hand side of the cylinder block and is supported in three bearings machined direct into the cylinder block. The valves are operated by castiron mushroom-type tappets with chillhardened tappet faces, with push-rods and hardened, forged steel rocker levers fitted with lead-bronze, steel-backed wrapped bushes.
A steel gear at the front of the crankshaft drives the camshaft and fuel pump through an idler gear; these gears have helical teeth. Fuel-pump timing is adjusted by slots in the fuel-pump gear, access being given by a covered opening in the timing case.
Lubrication is provided by a HobournEaton pump and a full-flow filter is mounted on the left of the engine. This filter may be fitted either vertically or horizontally.
A C.A.V. DPA distributor-type fuel pump incorporates a hydraulic governor and automatic advance and retard mechanism. The pump is mounted horizontally and feeds pintle-type nozzles.
These nozzles are retained in the cylinder head by left-hand-thread collar nuts which automatically centralize the injectors when fitting them and help to "jack up" the injectors when removing them if they should stick in their bores. A paper-element fuel filter is included. Cooling is by a centrifugal water pump, belt driven from the crankshaft, and a thermostat starts to open at 170-179° F. and is fully open at 199° F.
For cold-weather starting a C.A.V. Thermostart unit is fitted in the injection manifold and for extremely cold climates additional cold-starting equipment is available. A 12-v. starter is standard equipment, as is a belt-driven dynamo_ Test figures obtained with the new engine by Perkins engineers have shown that the Austin Omnivan carrying a 12cwt, load, which gives 28.8 m.p.g. with the standard petrol engine, returned 37.5 m.p.g. with the Four 99.
A Bedford CA van carrying a 10-cwt. load gave 46 m.p.g. with the Perkins unit. compared with 31 m.p.g. with the Bedford petrol engine, whilst on local delivery working, the oil-engine figure was 38 m.p.g., contrasted with 14 m.p.g. from the standard power unit.
The Beardmore Mark 7 taxi operating in London returned 35-36 m.p.g. with the Perkins engine, as against the 16-17 m.p.g. of the standard petrol unit.
Four vehicles with the new engine were tested on Tuesday by John Moon, of The Commercial Motor. A Bedford CA van with 5-cwt. load had a maximum speed of 65 m.p.h. and accelerated through the• gears from 0-20 m.p.h. in 5 sec.; 0-30 m.p.h. in 10.5 sec., and 0-40 m.p.h. in 18 sec. In direct drive 8.5 sec. were required to accelerate from 10-20 m.p.h.; 16.75 sec. from 10-30 m.p.h., and 26 sec. from 10-40 m.p.h.,
A new Trojan estate wagon with independent front suspension and fourspeed gearbox, carrying no load, gave the following acceleration results through the gears: 0-20 m.p.h., 5.75 sec.; 0-30 m.p.h., 11.25 sec.; 0-40 m.p.h., 19.75 sec. Direct drive: 10-20 m.p.h., 10 sec.; 10-30 m.p.h., 20 sec.; 10-40 m.p.h., 30 sec. Maximum speed was more than 50 m.p.h.
An Austin 152 Omnivan with 5-cwt. load, which was notably quiet and smooth, had a maximum speed of 53 m.p.h. and yielded the following acceleration times: Through the gears, 0-20 m.p.h., 5.5 sec.; 0-30 m.p.h., 12.25 sec.; 0-40 m.p.h., 21.5 sec. Direct drive: 10-20 m.p.h„ 10.25 sec.; 10-30 m.p.h., 19.5 sec.; 10-40 m.p.h., 33 sec.
A Beardmore Mark 7 taxi, having the new engine as standard and a Ford Consul three-speed gearbox, was also quiet, and had a 50-m.p.h. maximum.