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| K Type Profile |
At some time during 1931, H. N. Charles, the chief designer at MG, visited the old Wolseley factory, which by that time were producing Morris engines, to discuss the issues surrounding the low performance of the F type engine. The design of Wolseley OHC engines for their own cars and those engines destined for MGs were beginning to diverge as Wolseley were going over to chain drive for their over-head camshafts while Charles considered shaft drive to be the better option. Experimental modifications to the F engine, incorporating most of the work done on improving the four cylinder cars, resulted in a near 30% improvement in output but had not solved the chronic overheating problems. The design finally arrived at for the six-cylinder engine retained the basic layout but dispensed with the front ball-race, replacing it with a plain bearing with thrust pads for crankshaft location. The other main bearings were now made of steel, as were the connecting rods. Crankshaft dimensions were increased and the stroke reduced to 71mm giving the engine a capacity of 1086cc. A larger oil pump was fitted and the oil system incorporated full-flow filtration for the first time. Ignition was by magneto, mounted on the offside of the engine block. The biggest improvement was to the cylinder head, which followed the four-cylinder cross flow design with separate ports for each inlet and exhaust valve and fitted with three carburettors. The new engine was designated K-series and shared virtually no commonality with the old F unit. These small capacity, six-cylinder engines were probably designed with an eye to the 1100cc International class for racing and record breaking and the new range of chassis intended for the engine were called Magnettes, presumably to differentiate them from the F Magna.
The chassis was of similar basic design to the F type but of much stronger construction with deeper channel sections to the side rails and a deep cross-brace in the centre of the chassis for stiffening. The track was increased to 4 foot and the rear axle was altogether of bigger construction, similar to the Wolseley 14 unit. One of the chassis options was the fitting of an ENV pre-selective gearbox and the engines for these had modified valve timing to improve slow running at tick-over and so reduce gearbox ‘creep’. These engines were designated KA. The KB engine, using standard MG valve timing, was coupled to the newly introduced Wolseley designed four-speed gearbox via a twin-plate clutch. The KA was fitted to the new ‘pillarless’ saloons on a long wheelbase chassis, while the KB was fitted to four-seat tourers with the same long wheelbase and to the two-seat sports cars, built on a short wheel base version. The long wheelbase cars, both tourers and saloons, were known as K1s while the short wheelbase version was known as K2. A third version was also produced on the short wheel base chassis and this was known as the K3 with another engine variant also known as K3. These cars were principally designed for long distance racing and record breaking, although several were bought as straightforward, fast touring cars. The K3 was designed to be supercharged and a great deal of development was done both by the factory and by outside ‘privateers’ to increase the performance of this car and it would be true to say that the K3 remains the most successful and well known of any of the MG competition models.
The K series of cars in general were not spectacularly successful, the K3 apart, as they had heavy chassis and bodywork, particularly the four-seat and saloon models and were powered by relatively small, albeit efficient, engines. To compensate to some extent, the rear axle ratio was kept low but this only made the cars fussy at speed, and economy was poor. Late in production, another engine variant, the KD was produced which returned the stroke to 83mm and the capacity to 1271cc which gave the cars a welcome increase in performance.
To complicate the K series even further, when the N type engine was put into production (see N Profile for details), this was fitted to the remaining long wheelbase K chassis to produce the KN model ‘pillarless’ saloon. The more powerful engine certainly improved the appeal of these saloons, which now had a top speed of 75 mph and good acceleration. University Motors, the main MG distributors for the South East of England, bought up the unused K1 bodies and these too, were fitted to KN chassis to produce the ‘University Motors Speed Model Magnette’. The main difference between these cars and the factory built K1 tourers was in the mounting of the headlights and some of the interior trim.
K type specification
Wheelbase - K1, KN
Wheelbase - K2, K3
Track
Steering - K1, K2
Steering - K3, KN
Brakes
Wheels
Tyres
Chassis weight K2
Chassis weight K3
Chassis weight K1, KN
Weight of complete car:-
K2 open two-seat
K1 & KN open four-seat
K1 & KN Saloon
K3 two-seat racing
1934 K3 'pointed tail' |
9' 0" (2.74m)
7' 10" (2.39m)
4' 0" (1.22m)
Marles Weller
Bishop Cam
13" drums, cable operated
2.75" x 19" side laced wire, Rudge type
4.75" x 19"
14 cwt 48 lbs (733 kg)
14 cwt 84 lbs (749.3 kg)
15 cwt 98 lbs (806.5 kg)
18 cwt 28 lbs (927 kg)
19 cwt 56 lbs (990.6 kg)
21 cwt (1067 kg)
18 cwt 56 lbs (939.8 kg)
17 cwt 84 lbs (901.7 kg) |
Bore
Stroke - KA, KB, K3
Stroke - KD
Capacity - KA, KB, K3
Capacity - KD
Power output - KA
Power output - KB
Power output - KD
Power output - K3 |
57mm
71mm
83mm
1086cc
1271cc
39 bhp
41 bhp
48 bhp
approx 120 bhp depending on tune |
K1 1st July 1932
K2 6th March 1933
K3 26th October 1932
KN 31st July 1934
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to 14th June 1934
to 9th January 1934
to 23rd August 1934
to 2nd October 1935
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K1 four-seat tourer
K1 Saloon
K2 open two-seat
K3 two-seat, racing
KN saloon/UM tourer
Chassis only |
97
74
20
33
201
35 |
K type pictures:
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