Borgward Isabella
Reviewed by Unique Cars and Parts
Our Rating: 4
Introduction
The 'Isabella' had a 1493cc inline 4 cylinder OHV engine of 75 x 84.5 mm bore and stroke with a single downdraft carburettor, fitted to an extremely short intake manifold inside the rocker box. This actually gave the appearance of an OHC engine as opposed to it being an extremely efficient pushrod powerplant of 60-bhp din (65 bhp SAE). The pretty car was spacious, thoroughly well made and comparatively light for its size at 1,000 kg.
Light aluminium alloys were used extensively for the gearbox,
cylinder head and on many engine parts, covers, etc., as opposed to the cheaper and noisier pressed steel. The body not only looked ultra new for 1954 it comprised a unit construction body and separate front and rear sub frames, the front one being rubber mounted. The front
suspension featured unequal wishbones, coil springs and telescopic shock absorbers, checked by an anti roll bar.
At the rear was a fully independent swing axle, again featuring coil springs and telescopic shock absorbers. The front of the axle was located by radius arms, pivoting in rubber bearings, the differential being mounted to the rear subframe in large rubber bushes. Very large hydraulic drum
brakes were used with twin leading shoes at the front and single leading at the rear, complete with wide aluminium alloy shoes.
The gearbox had four all
synchromeshed forward speeds and one reverse and was actuated by an extremely efficient and precise column gearchange marred only by its rather long throws. The handbrake was mounted under the dashboard and was the umbrella type that, with the bench seat, allowed three across the front and three across the back. The polished Bakelite dashboard contained three large gauges, a clock/temperature gauge, petrol gauge and the
speedometer. There was a cigarette lighter with a plug in map reading light, three ashtrays, one under the dashboard and two in the rear side panels.
Ample storage space was provided comprising two door pockets, glove box and later supplemented by two retractable cord strung tubular framed map holders, mounted on the side of each footwell. Unusually, the doors had separate wind down quarter lights providing draft free ventilation. Separate heaters for driver and passenger were provided, as were separate controls. The large white
steering wheel actuated a lightly weighted and rubber coupled worm and peg or worm and roller
steering box with three turns from lock to lock. The
steering was very precise with a turning circle of around 32 feet; later cars being fitted with a hydraulic telescopic
steering damper. The very well balanced weight distribution coupled with the low centre of gravity and all round independent
suspension endowed the car with very high cornering powers.
The fuel consumption was low at around 34 mpg and the top speed was 87 mph yet Carl F. W. Borgward kept the price low by a mixed price calculation with his other products. The only real vices were the vertical fixing of the front bulkhead to the floor making it slightly awkward to rest your feet and the rather low driving position of the front seats, but these were only minor faults against all the advantages. Although the factory-reconditioned units for items such as the engine and back axle were relatively expensive in
1954, there were no rivals.
1958 Borgward Isabella Range with Isabella TS Convertible
The first in the Borgward line was the normal Isabella sedan with 1,493 c.c. four-cylinder engine giving 60 b.h.p., then the Touring-Sport with 75 b.h.p., the TS de luxe, then the TS coupe, and recently at Frankfort, the Isabella TS convertible. Basic construction was the same for all; unit structure in steel, using the motor supports, and the floor, with central tube and transverse stiffeners as main structural elements. Front suspension was by wishbones and coil springs with anti-roll bar; rear end construction was swing axle independent, with longitudinal radius arms and coil springs. The TS engine had an 8.2 to 1 compression ratio, and with Solex Downdraught carburettor producing a respectable 75 b.h.p. from 1.1 litres.
Recent innovations for 1958 included drop-centre safety steering wheel, new instrument panel with ribbon speedometer and trip recorder, and larger fuel tank of 13 gallons. Both the coupe and convertible had elegant lines, and high-grade detail finish, deep separate front seats, with adjustable backrests which dropped to full recline at a touch on a lever, padded instrument panel and, on the coupe, plastic head lining and padded sun visors, with vanity mirror on the passenger's side. An unusual detail: wind wings wound down into the doors, which helped to discourage entry of water on wet days.
A short run on a twisting road circuit conducted in 1958 showed the Coupe to be a lively smooth riding job with an unusually good and precise steering column shift controlling an efficient all - synchromesh box. When cornering fast there was definite oversteer, and eventually the tail would break away, but recovery was rapid thanks to the quick steering (3.5 turns lock to lock) and there were no complications. The all-independent suspension showed to advantage in the comfortable ride, and in sure wheel grip during heavy braking. (Brakes had a friction lining area of 121 sq. in.). No official factory figures were quoted for the coupe, but with the generous scale of finish and equipment, it was unlikely to weigh much less than the sedan if at all, i.e., 3,015 lb.
The Borgward factory claims included a maximum speed of 93 m.p.h. and fuel consumption of 25 m.p.g. With 5.90-13 tubeless tyres, and axle ratio of 3.9 to 1 the car was geared to do 17.4 m.p.h. at 1,000 r.p.m. in top gear, which meant easy main road cruising without too much fuss from under the hood. It was a kind of car that was growing in popularity, giving luxurious travel for two with plenty of luggage, and emergency space for two more, with a sporting appearance.
Borgward Isabella Quick Specifications:
Engine: 4-cylinder pushrod o.h.v. 75 x 84.5 mm., 1493 c.c., 8.2 to 1 compression, 75 b.h.p. installed at 5200 rpm. Maximum torque, 82.4 lb. ft., at 2800 rpm
Transmission: 4-speed all-synchromesh gearbox, steering column shift; hypoid final drive. Overall ratios, 15.05 to 1, 8.38 to 1, 5.30 to 1, 3.90 to 1
Dimensions: Wheelbase, 8 ft. 6 7/16 in. Track, front and rear, 4ft. 4 5/8 in. Length, 14 ft. 5 in. Width, 5 ft. 7 1/8 in. Height, 4 ft. 5 1/8 in. Ground clearance, 6 7/8 in.
