80,000 MILES IN TWO MG-Bs

FOLLOWING recent correspondence about the Triumph TR range, it may be interesting to relate the experiences of two staff MG-Bs over a period of some 8o,000 miles, being a similar, if perhaps more sedate, kind of car.

The first example, FJB 535 C was a black MG-B sports, having the five-bearing crank engine and overdrive fitted. It proved to be incredibly reliable, and during the 45,000 miles it was used by a member of our staff, suffered no major fault whatsoever.

Initially it was supplied with Dunlop C.41 tyres. These produced a pronounced oversteer characteristic in the handling, with resultant rear tyre wear. At 18,000 miles the rear tyres were replaced with G.8s which increased the oversteer. Consequently, at 24,000 miles, the whole set was replaced with Avon Radial tyres. These proved to be absolutely perfect for the car, and made the handling completely vice free. In the dry, it was impossible to cause loss of adhesion under normal hard driving conditions on the road. It would need the freedom of a race circuit to do so. In the wet they gave plenty of warning of impending loss of grip under extremity, but this was so perfectly controllable that the car could be steered almost entirely with the throttle, backing off to induce a trace of oversteer or adding power to provoke understeer. It seemed that Avon Radials suited the "B" like Michelin "X"s suit a "deux cheveaux". One front shock-absorber needed replacing due to a leaking seal at 12,000 miles, and the exhaust system suffered damage due to its lowness and the use of the car following rallies. Two or three welding sessions at various times held this together until 25,000 miles, at which time it was replaced by an excellent custom-made bottom pipe from JanSpeed. This lasted until the car was passed on to another member of the staff at 47,500 miles.

An early improvement had been to replace the standard sealed-beam headlights with Marchal Asymmetric units, which not only had an improved output but could be switched to Continental dipping. At the same time, the original neoprene rubber wiper blades and arms were replaced with Trico wire frames and natural rubber blades. These did not lift at speed and in conjunction with the Trico "add-on" electric washer motor provided much improved windscreen cleaning. Marchal twin-horns replaced the original inaudible and heavy ones.

Some trouble was experienced with front disc roughness, which did not respond to skimming, so the discs were replaced at 15,000 miles. Other expenditure was only the odd bulb, plugs and points, and the dipswitch.

When the car was passed on to a further member of the staff at 47,500 miles the tyres were still in good condition and even now, some 36,000 miles from new, they have about 3 millimetres of tread left all round.

The new owner handed the car to Bill Nicholson for a check-up and rectification as necessary, and this commenced with front suspension overhaul, replacement of all bushes and the dampers. New discs and pads were needed and the rack and pinion needed adjustment. The cylinder head required some new valves and seat grinding. These rectifications seemed reasonable after nearly 50,000 miles of hard use including rally coverage and fast Continental driving.

The original twin 6v. Lucas batteries are still in good order now, despite being five years old. Possibly their position under the rear floor sitting in the cold has helped in this respect, even though this dreadfully inaccessible site tends to let them be forgotten.

The exhaust needed replacement again at 50,000 miles and Brian Muir at Brabham Conversions fitted one of theirs 12,000 miles ago, which shows no sign of deterioration. The appearance of this car was enhanced by the fitting of a new hood by the Car Hood Company at 52,000 miles.

Striking a fallen object burst a tyre and, as was later discovered, also cracked a universal joint, and now at 60,000 miles the 2nd gear synchromesh is rather worn, but the engine is as crisp and powerful as ever. It still shows 60-70 p.s.i. oil pressure and sounds fit for another 40 or 50,000 miles without worry.

FJB 535 C had proved so fine a motor car that its original owner opted for the GT version when the open one was passed on. This was also ordered in black as the other looked so well, a fact which probably contributed to the delivery being six months after the order was placed. Unfortunately, WLT 550 G was not to prove nearly so reliable as its predecessor and a succession of faults began to develop early in its life. The first item to go was the expansion box on the exhaust system. This was a different pattern from the older car and was formed from a cylinder with crimped ends. At 3,500 miles the whole of the underside of this cracked due to resonance and blew out a piece about 4 in. x 3 in. Fortunately, this happened near to a BLMC agent at Machynlleth in Wales and was replaced under warranty in a very short time.

Uneven braking then began to make life difficult and it took several visits to the London main depot to eliminate the possible causes of this and discover that the discs were at fault. Subsequently, failure of the rear-wheel brake slave cylinder rubbers, both sides at different times, caused further braking bothers and in one case destroyed the axle oil seal as well. This, of course, necessitated replacement brake liners. The next bother was a blown cylinder-head gasket at 12,000 miles, despite careful checking of nut tightness with the appropriate torque setting on a wrench.

Later the engine developed a subtle rattle at certain revs. This was one of those hard-to-trace but insistent noises that promise ill for the future, and it took a great deal of time and replacement parts at the factory to eliminate this.

Since that time the car has been behaving itself, with the exception of one of the slave cylinder jobs referred to earlier, but the engine still seems rather noisier than that of the original car and produces less confidence in its future behaviour.

WLT 550 G was supplied with Pirelli Cinturatos on its wire wheels and while these provide good handling and reasonable adhesion in the dry, they do not compare so favourably in the wet with the characteristics of the Avons fitted to the open car. Perhaps this is a question of "horses for courses" and the Pirellis would be more suited to an independently-sprung car. Their wear rate seems rather higher than expected, and at 20,000 miles they are almost finished at the rear.

Perhaps WLT 550 G was a "tea-break" car and is not representative of the marque. Hopefully, all the early bugs have now been sorted out and it will now live up to the fine example of its predecessor. It is hoped that this is the case, for in GT form the MG-B is a roomy and rapid means of transport and is ideally suited for the sort of long-distance assignments that MOTOR SPORT entails.

Both MG-Bs have provided many enjoyable motoring miles, combining a reasonable standard of comfort with good performance, considering the engine is only 1,800 c.c. Fuel consumption has been at the rate of 28-30 m.p.g. on distance runs, dropping to 23-25 around town. With overdrive gearing at 22 m.p.h. per 1,000 r.p.m., it is comfortable to cruise at 4,000 revs., representing 88 m.p.h., for long spells, with the odd 500-1,000 r.p.m. in hand which can be used to snap out of overdrive to accelerate when needed.—L. A. M.