Launched in May 1939, the TB did not look anything different from the TA and it was not until the bonnet was opened that the differences became apparent. However, there were some cosmetic changes externally, with the wire wheels now becoming centre laced and the semaphore type traffic indicators that were evident below the windscreen pillars on the TA were dropped on the two seater TBs.
It was during late 1938 and early 1939 that the XPAG engine was developed. It was a totally new engine with a fairly high state of tune and featured an enlarged cylinder bore giving a capacity of 1.250 ccm, which was down 42 ccms on the TA engine. Despite this drop in capacity, the car ended up in the next taxation class going from to 10 to 11 horsepower. This was a direct result of increasing the bore and the car became a victim of the somewhat ridiculous horsepower formula. Making its first appearance in the TB, the XPAG engine would power almost every MG car and many special racing cars for the next 15 years and MG could not have foreseen that the engine would prove so successful, particularly with the Gardener MG that achieved over 200 mph. Phenomenal power outputs were achieved with the XPAG engine, particularly when supercharged and though it resembled the MP JG engine in as much as it was an overhead valve pushrod unit, that is where the similarity ended.
The TB engine was altogether more appealing to the MG fraternity because it was capable of far more tuning than the old TA engine and was much more reliable into the bargain. Everything the TA engine lacked, the TB engine had in its favour. It had the larger bore and a shorter stroke, thus allowing faster and safer high revving. Maximum power was achieved at 5,250 rpm and the output was a healthy 55 bhp for the standard road car. This extra power and higher rev limit ensured that there was no loss of speed at the top end of the range and the car performed well in the 55 to 70 mph area. The acceleration was marginally improved over the TA with a 0-60 mph time of 22.7 seconds which was nearly one second faster.
Because the XPAG engine had a stronger block, more efficient cylinder head and stronger counterbalanced crankshaft, the engine was far more receptive to tuning than its predecessor and with a far lighter flywheel the engine was altogether more responsive to accelerator movements. The XPAG was specially produced to power the TB.
The cooling system on the XPAG is worthy of mention because it was due to the design of the system that allowed the additional performance to be extracted from this now legendary engine. A rather ingenious flow system ensured that the block ran warmer than the cylinder head which was ideal for performance.
There was also a new gearbox which was also employed on the VA saloon, with synchromesh on 2nd, 3rd and 4th instead of just the top two gears, but still in the same familiar casing. The gear ratios were also altered to cope with the lower rear axle ratio and these new ratios gave a road speed of nearly 16 mph per 1000 rpm which produced a very comfortable cruising speed of over 65 mph. An additional feature was the provision of a telescopic steering column which now became standard.
This car was produced in the MG factory on the 12th of October 1939 as the 332th piece of 379 MG TBs built. It was first registred as 9th of ten MG TB police cars for in Dover, UK with the first registration plate GKL 69.
Engine and mechanics have been modified by Harry Lester for racing direct after the WWII. The car stayed in the inventory for another 10 years used probably only for testing of modifications and bodies, no racing history is known in that time.
In 1954 Harry Lester prepared 5 new bodies in aluminum, three for Le Mans 1955, two for Mille Miglia 1955, one of them an open two-seater. But the Monkey Stable racing team decided to rebuilt them in fibreglass, so the aluminium bodies never raced and stayed in Lester‘s inventory. The original chassis and engine were connected with the OTS prototype M15 body in 1955 or 1956 by Harry Lester from the sold inventory to Peter Cottrell. He sold it later to Lorraine Engineering, based close to the Goodwood circuit, who run the car at least until 1959.
The car stayed later with two owners from Havant, UK, which is also close to the Goodwood circuit, probably used for amateur racing for a couple more years. The car was then 25 years dry stored over there as a non-running project until sold to Germany, where the restoration of the car was finished in 2007 and drove the car in 2010 AvD Oldtimer Grand Prix at Nürburgring and in 2020 the 1.000 miles of Czechoslovakia. The car is currently road registered on a Czech historic registration plates.
1945 engine and mechanics modified by Harry Lester for racing
- 1.250 ccm, 100+ PS, Aluminum Laystal Head, 2 x 1 ¼ HD4 SU carburettors, Derrington exhaust / intake manifold, Race – magneto, Alfin Break drums
1955/56 connected to an aluminium body (OTS prototype M15 type from 1954/55)
- total weight: 650 kg
Mille Miglia, good 1,60 factor.
Giro di Sicilia
Coppa d’Oro delle Dolomiti
Coppa delle Alpi by 1000 Miglia
Vernasca Silver Flag
Pebble Beach Concours d’Elegance
Amelia Island Concours d’Elegance
Chantilly Arts & Elegance Richard Mille
Concorso d’eleganza Villa D’Este
|Engine||1.250 ccm, 100+ PS, I4|
|Steering||Right Hand Drive|
|Layout||Rear Wheel Drive|
|Color - exterior||Silver/Bare aluminium|
|Color - interior||Black|
|Miles/Kilometers shown||700 mls|
|Chassis / VIN||TB0583|
|Location - Country||Czech Rep.|
|Location - City||Liberec|
2-door roadster body type; RWD (rear- wheel drive), manual 4-speed gearbox; gasoline (petrol) engine with displacement: 1250 cm3, advertised power: 40.6 kW / 54 hp / 55 PS (brake), 100+ PS from the race prepared engine, torque: 87 Nm; characteristic dimensions: outside length: 3543 mm, width: 1422 mm, wheelbase: 2388 mm; reference weights: estimated curb weight: 800 kg / 650 kg for the racing version top speed: 129 km/h (80 mph) (declared by factory) and around 160 km/h (100 mph) for the racing version; accelerations: 0-60 mph 17.8 s; 0-100 km/h 19.3 s