The Nicholson-tuned M.G-B

Ever since the M.G.-B was introduced it has been the subject of snide remarks from the competition fraternity on the score that it is too heavy to be anything but a quick touring car, and from the King’s Road set because it looks too much like a Midget. Be that as it may, the “B” has endeared itself to thousands of owners for its unobtrusive performance, comfort and reliability, while a number of competition drivers have proved it to be a useful long-distance racing machine when tuned and lightened. Bill Nicholson, one of the most successful drivers in M.G.s at the age of 48, started his own garage and tuning business in Northampton little more than a year ago and is now marketing a range of performance tuning kits, ranging from a Stage 1 cylinder head at £25 plus fitting to a £335 Stage 6 racing-engine conversion. For the purpose of our road test we drove a “B” with the £75 Stage 2 conversion consisting of a modified and flowed head plus an improved inlet manifold equipped with a pair of 1-3/4 in. S.U. carburetters (one size up from standard equipment). The car had overdrive and a 4.3 axle ratio, and suspension modifications to cope with extra performance consisted of lowered front and rear springs, a heavier (5/8-in.) anti-roll bar and adjustable rear shock-absorbers, the latter item not being needed unless the dampers are well worn.

The net power output is increased by some 12-14 brake to about 107 net, and although this has not been tested on a brake it appears to be a genuine estimate. In standard form the sports car accelerates rapidly but undramatically, while the Nicholson conversion introduces a keener edge to the pulling power and improves the top-end performance considerably. As an ex-development engineer with B.S.A. and Jaguar, the tuner is a past master at making engines breathe properly and his formulae work well on this unit.

In the prevailing cold weather the engine took several miles to warm properly and overcome its tendency to stalling, and as the water temperature fell below 160 F. on motorways also there is a clear indication that water-heated inlet manifolding is required. The selection of overdrive in the specification is a wise one, allowing better acceleration with the low axle ratio and more restful high-speed cruising. The speedometer was calibrated for a 4.1 axle, but allowing for the error we still found that the car could reach 60 m.p.h. from rest inside 11 sec. and achieve 100 m.p.h. within 30 sec., the time it takes an unmodified version to reach 90; maximum speed is raised from 109 m.p.h. to 117, comfortably inside the upper limit of 6,000 r.p.m.

So smooth was the five-bearing engine that it felt like a balanced unit, though this was not the case. In overdrive top the legal limit of 70 m.p.h. was reached with 3,500 r.p.m. on the tachometer, and it proved exceedingly hard to keep down to this speed—100 m.p.h. is a much more natural gait, cruising with 1,000 revs in hand. With a 9.5-to-1 compression ratio the car was on a diet of premium fuel, consumed at 24.3 miles per gallon, which can be considered a very reasonable figure. The electric fan installed was not needed during normal driving, when the temperature ranged from 150-185 F., but once in a solid London traffic jam it was found necessary to switch the engine off for a few minutes.

The handling was quite substantially improved at the expense of the rather soft saloon-car ride that characterises M.G.s—reducing the tyre pressures from 30 lb. all round would have made it slightly better, and it might be a better compromise to soften the rear dampers and fit the 3/4-in. anti-roll bar at the front. The lighter anti-roll bar practically eliminated the roll oversteer tendency, and the heavier one should do so completely.

Before returning the car we met Bill Nicholson at Silverstone to try his four-year-old, but still immaculate, racing “B.” With seven good wins to its credit last year the car is an exceptionally nice one to drive, having well-sorted handling that would make it an obvious choice for someone taking up marque racing. Surprisingly, the three-bearing engine has been retained, though not for much longer, and when we tried the car it was fitted with a new cylinder head designed to extend peak power up to 7,000 r.p.m. This it seemed to do most successfully, pulling 122 m.p.h. on the straights without any fuss. The output is likely to be around 140 b.h.p., not inconsiderable for a production-based 1,788 c.c. unit, and with two up to begin with we recorded a two-way 0-100 m.p.h. acceleration time of 19.9 sec.

Seemingly the car had no vices—we were given no instructions or warnings before setting out on the Grand Prix circuit—and there is sufficient adhesion to lift the inside rear wheel sometimes, indicating that a limited-slip differential could come in handy. Despite patches of frost on Woodcote and Club corners, severely restricting enthusiasm, Nicholson was able to lap consistently in 1 min. 56 sec., four seconds outside his own marque class record. The car has been lightened to around 17-1/2 cwt., but £500 should go a long way toward preparing a replica such as that used by Jean Denton winning the Embassy Trophy in 1966.—M. L. C.

Performance — Stage 2 modified M.G.-B (m.p.h./sec.):

0-30/3.1

0-40/5.3

0-50/7.2

0-60/10.6

0-70/14.1

0-80/18.8

0-90/23.0

0-100/28.9

Speed in gears (m.p.h.):

1st…..30

2nd…46

3rd…73

4th…99

4th overdrive…117.

Fuel consumption: 24.3 m.p.g.

Cost of conversion as tested, including fitting: £113 17s.

Conversion by: Bill Nicholson Ltd., Wellingborough Road, Northampton.