|
Track Test, Motor 1971, week ending February 6
Last year Bill McGovern drove George Bevan's 1 litre Imp to eight lap records, seven class wins and two 2nds in only 11 starts. Bill also won the RAC Saloon Car Championship and scored the only British class win in the 4-hour Tourist Trophy, our qualifying round for the European Touring Car Championship. After the colour section Michael Bowler track tests the £2500 Imp and Chris Hartley looks at the team's activities.
As practised road testers we find we can chuck a road car around very soon after getting into it, unless it's something like a Citroen SM. But I have never found this to be true of track cars - partly for fear of bending someone's pride and joy, but mainly because their responses are too fast to make such treatment useful. The Bevan Imp, though, was different. It had all the chuckability of a roadgoing Imp and inspired just the same confidence that it would return from quite outrageous attitudes. Our test took place at Club Silverstone on a wet track, which allowed such experiments to take place at a sane speed.
 | |
 |
Inside it looks pretty standard with the ordinary Imp Sport instrument binnacle - disconnected apart from the oil pressure gauge - with the oil and water temperatures plus rev counter alongside. Even the pedals are standard. There is some carpet and the 'passenger' seats are just as in your Imp. The adjustable Restall driving seat and dished steering wheel, tailored to suit Bill McGovern, also suited me even though I am smaller than Bill.
The car was shod with its wet 970 compound Dunlop boots with 4.75/10.00 x 13 both front and rear for wet use - 13i. wheels being homologated for Imps; dry boots use 350 compound and have the rear width increased to 11.50in. Another wet adjustment is to decrease the negative camber from 1½-2° to ¾°. Normally you get enough roll on corners to decrease the negative camber to zero and thus put the tread flat on the road. In the wet you don't get enough grip to generate much roll and so the initial camber must be decreased.In fact roll is pretty limited with 2in. front suspension movement and 2½in. at the rear, but enough to vary camber angles on swing axles.
The engine seemed completely untemperamental, and quick to buzz up to its 9000rpm-plus with the power coming in around 5500 rpm. |In fact third and top gears, lower than standard, give a very close ratio set and the engine can be kept for ever between 7 and 9000 rpm. The standard Imp gearlever with its very short movements is ideally suited to a racing car when you want your arms away from the wheel for as short a time as possible. It is always difficult to sense acceleration on a wide track with an open exhaust emitting almost a constant pitch buzz, but it stepped off well, the power giving an impression that the car was suddenly super-loight. On those ratios it pulled 9000 rpm on the way down to Woodcote (about 108 mph), completely stable and surprisingly disinterested in twisting up ridges.
Handling was slightly Imp-like with quite a marked contrast between foot-off oversteer and power understeer unless you were on the limit, when excess power could be used to keep the tail out.
Going gingerly into Copse, which was very slippery, I felt the front running outwards and it required a certain amount of courage at first to boot the throttle. Into Becketts it was tremendous fun. Going slowly in at first... then accelerating ploughed the nose outwards.
Going in faster, though, starting the turn with the throttle closed, brought the tail round and then with appropriate lock and power the tail could be kept balanced until the car was pointing down the next straight. Too much correction of the initial tail-out would result in full grip followed by power understeer again. (Quite a delicate balance really with instant movements of the steering wheel required to maintain the attitude - it was much easier to do this with one hand as the steering is quite low geared, and I gather Bill does the same in the dry as well.)
Second gear is used here, the precise gate encouraging a straight drop from fourth to second.
Confidence came quickly, but perfection at Becketts was rather rare. After a few laps I found it quicker to hold third along the pit straight which took it up to 9200 rpm. But in the dry, when the exit from Woodcote would have been faster, fourth would be required under the Motor bridge.
Without braking very hard, I was touring around at 1min. 18½sec. or so. Then I decided to use the brakes properly I sailed past sanity breaking marks, my right foor still flat. The retardation from the brakes was fantastic considering the still wet track - standard pads pulled the car up really square just keying the tyres into the track.
I did just one lap of this harder treatment and that was instantly 1½sec. off at 1min. 16.9sec.; It seemed quite impossible to lock the wheels, I thought the pedal would probably bend first.
I have driven last year's saloon champion, the 1 litre Arden Mini usually driven by Alec Poole. In that car I went round Club Silverstone in the dry in 1min. 13.0sec. The Mini was faster down the staight by some 7 mph, but was not quite as easy to drive as the Imp. The Imp is more stable in a straight line and can be set up for a corner, it then gets round faster than a Mini.
I would have liked a dry comparison, but suspect that the Imp would be the faster because I understood its handling more. The Imp though, had a year of development in between. I have a soft spot for Imps anyway, but I certainly enjoyed driving the fastest Imp that has any pretensions to the car you can buy.
The Bevan Imp is the most standard-looking successful racer I have seen; it even starts like a road car. It just requires two or three pumps on the throttle to prime the Webers, and the starter brings it to life.
But underneath this relatively m undane skin, there is a lot of detail work. The car weighs about 14½ cwt., some 100 lb. over the Group Two class limit, and uses a glass-fibre bonnet and boot, which are homologated Imp parts. For 'Clubbies' the standard steel doors are replaced by glass-fibre ones. All windows except for the screen are perspex, and inside a durall roll cage, fabricated by George, provides roll-over protection. This roll-over bar has already been tested; it came out of a car written of at Crystal Palace.
The immaculate metallic blue paintwork was done by Peter Radford, a friend of George's, and the car carries stickers on its flanks for Dunlop, Minilite, Burmah, Castrol, Champion, Koni, Britax, Ferodo, Hepolite, Glacier, Dellorto Serck, Avanti, and Piper. George Bevan explained that not all these firms sponsor the car, but they do use their equipment.
The suspension is basically standard Imp with settings evolved from testing, rather than theoretical studies. The swing axles at the front are fully welded and stengthened with the springs shortened to give negative camber; as Michael Bowler explained in the track test up to 1½° when the car is running with super wide rear tyres. The camber is varied by moving shims from top to bottom of the stub axle.
At the rear the semi-trailng arms are welded and strengthened, but unlike most other competition Imps double concentric rear springs are used with a stepped spacer At the base to vary the rate of the central spring. Armstrong shockers are fitted at the front, Konis at the rear: "Koni make a special and very expensive, shock absorber with bump and rebound adjustment - the rear shockers on this car are very critical", explained Goerge.
The heart of the car is the engine. The Rally Imp engine blocks come from Chrysler UK. They are sent to Jacey Plastics Engineering of Erith, Kent who check the top deck and bores are true. George Bevan has high praise for this company, who will work all night to get a block ready; they have been knowm to leave one on his back doorstep at 2 am. Thompson Engineering at Crystal Palace check the Tuftrided crankshaft, again supplied by Chrysler UK, as are the standard Imp conrods.
Hepolite supply the pistons, Glacier the bearings. The engine is checked after every race and even after four hours of racing in the Tourist Trophy race the unit was still in excellent consition.
George's son Peter does the cylinder heads. He was taught by Bob Gayler when they both worked for Baldyne. Peter starts with an Imp Sports head, bores and cleans the ports and fits works nimonic competition valves - 1.4 in. inlet and 1.125 in. exhaust.
The compression ratio is upped to 11.5 : 1 and the Champion R60 plugs are fitted. The engine starts easily with these and George reckons that, if required, the car would do at least three practice sessions on the same set.
Needless to say the camshaft comes from George's close friend Bob Gayler at Piper and the engine breathes through a pair of 40 DCOE Webers.
A Lucas Sports coil provides the sparks which are then distributed by a Lucas competition distributor.
Drive to the Knight four-speed gearbox is through a Formula 3-type clutch with a sintered lining, and from the gearbox the power goes out to the wheels via a Knight limited slip differential and standard competition driveshafts.
Integral with these shafts is the component which has given the team most headaches during the past season - the rubber doughnuts. Unfortunately the standard competition parts are not really up to the job since when the car is cornering hard, it picks up both inside wheels and torque reversal overloads the doughnuts. As a precaution they are changed after every practice and race - this alone costs about £140 during the year.
In turn this weakness sets a limit on the ride height of the car since, if it is lowered further, the driveshaft angularity becomes too much for the doughnuts and they break even more readily. If this problem could be overcome, the car could be lowered and should go even faster.
The stop department is catered for by the modified Vauxhall Viva discs at the front and standard Imp drums with Ferodo linings at the back.
Such is the specification of the car that waltzed all over the opposition last year. George reckons all this work has raised the price of his £315 Imp to about £2500 - the price he asked us to insure the car for during our test.
The British love an outsider, and preferably a private entrant, who will carry off the laurels in the face of heavily sponsored factory teams. And it's good to know that even today such success is possible. Last year the combination of George Bevan's Sunbeam Imp and Bill McGovern clinched the RAC British Saloon Car Championship by scoring eight class wins and two 2nd places in 11 starts.
Such success doesn't just happen overnight; it is the result of many years spent in the background gaining experience and expertise. George has been involved in motoring competition since 1938 when he was a mechanic at motorcycle meetings. He first became involved in motor racing in 1964 when he entered and prepared an Austin A40 for his son Peter (and Ginger Payne). This was rather an expensive exercise (the car needed a new gearbox every second meeting) and the team were always being carved up by a driver called Bill M cGovern. After three years they gave up. Peter subsequently got married and retired from active participation, so George looked around for 'another idiot' to drive his car, having decide that he would either run a Ford or an Imp during the 1968 season.
Bill, meanwhile, had been driving Imps for thre years for Paul Emery. In 1968 Bill and George set up a partnership, which has lasted ever since.
 From left to right: Norman Winn (leaning against the pit rail back to camera), George Bevan, Chris Hartley, Michael Bowler and Bill McGovern |
For both men, racing is a part-time occupation. Bill is married and has four daughters. ("They were born before I started racing in the Mini.") He owns a furniture business in London. George makes cookers for Chinese restaurants, which is probably where the stories of building race-winning engines on the kitchen table spring from. George's role in the team is sponsor, team manager and car builder, though for the 1970 season he had a helping hand from Keith Tilbrook. For the 1971 season he will have the assistance of Norman Winn who worked in the Rootes Competition Department and who was Alan Fraser's chief mechanic during their Imp days. Norman will take over the job of building the engines and will go to every race with the team.
In 1968 and 1969 the Imp was run in Club events. In the first year they had problems with distributors and dry liners, but 1969 was very successful until Bill rolled the car at Crystal Palace.
Bill is one of those delightful characters who can tell you they are the greatest without being conceited about it. I remeber his being asked in one of those embarrassing start line interviews during the 1969 season whether he thought his success was due to the cr or his driving. "95 percent me, 5 percent the car" came the reply. And he still is as confident, and in the Bevan Imp would have admitted second best only to the late Jochen Rindt. He has firm opinions about the future of motor racing and expresses them in an amusing and articulate manner, which made his explanation of the accident at the Palace all the more interesting.
A shock absorber pulled off, which slewed the car sideways with two wheels on the grass. Ultimately the car rolled and looped the loop ("All hell broke loose inside the car and I thought my number was up"). But though the car was a complete write-off, Bill escaped unhurt.
One month later the team were back in business with a new car built up from a secondhand Imp bought for £315. And they won again the first time out. It was this same car that took Bill to the victor's rostrum so many times in 1970.
Towards the end of the 1969 season George did some homework on lap times when he realised tha his club car was going faster than the Group Two class competition. He reasoned that if past form was an accurate yardstick, class victory in Group Two saloon racing was his for the taking - if he decided to take the plunge and enter Bill and his Imp in the big time in 1970.
So during 1970 the metallic blue Bevan Imp became a familiar sight at events which formed qualifying rounds for the British Saloon Car Championship. The car competed in three club events during 1970 and in the second, they beat John Turner's Imp which later won both the Osram GEC and Atlantic saloon car titles substantiating Bevan's claim to run the fastest Imp in the world.
For the first three races of the 1970 season the team were forced to run without disc brakes at the front; standard doughnuts in the driveshafts; and standard clutch parts, as the necessary competition bits were not homologated until April. A direct result was that during the first championship race at Brands the clutch let go and a rod went through the side of the block - the only retirement during that year.
The 2nd place at the British Grand Prix round was caused by a deflating rear tyre and at the |Gold Cup by a cracked block which had by then done 10 races - including the four hour long TT.
Their success was such that during the year one team manager (of a car in the 1300cc class) is reputed to have asked George to slow Bill down as he was making everyone else look silly; and by the Guards Trophy meeting on August 13, Bill McGovern and the Imp had the championship sewn up.
Many people thing the team have Chrysler UK backing, but this is definitely not so and they have bouht all their parts - admittedly at a reduced price. Des O'Dell, the manager of Chrysler UK's Competition Centre, has provided a service car at all meetings where the car was competing to make parts readily available, but this service has also been available to other entrants of Chrysler UK products.
Though there is no active works participation, Des is keen to get across the message that Chrysler has a friendly competition manager who is very willing to help private owners who want to compete with Chrysler UK cars in motoring competition.
In the early part of the 1970 season, for example, Des spent a lot of time discussing the specification of the Sunbeam Imp with George Bevan and when there were breakages , they liaised to get things right.
This effort has been amply rewarded, for Chrysler must have reaped immeasurable benefit from both the success of the Bevan Imp in racing and that of Peter Harper's car in autocross. That Chrysler thought sufficiently well of the Bevan team's efforts to display their Sunbeam Imp on the CUK stand at the Earls Court Motor Show was perhaps justification for the team's work in 1970.
For 1971 George and Bill are again planning to compete in the RAC Sallon Car Championship rounds, and there are people in the saloon racing world who reckon the team will repeat their 1970 success. As added insurance George is currently building a spare car and four spare engines. On top of their home commitments, they plan to go abroad, possibly to Zandvoort, to take on the Abarths (which they so convincingly beat at the TT).
As a team they are well organised and thorough in their preparation. For example George keeps a book in which details of every race and practice session are recorded, including Bill McGovern's times during a test day at Brands the previous weekend to check the car before our Track Test. This occasion incidently was the first time Bill had ever heard his precious mount being driven around a circuit - "doesn't it sound angry?"
But the team's organisation extends beyond the preparation of the car to better than showroom standards - they arrived at Silverstone exactly on time and George's wife had thoughtfully provided coffe and sandwiches for everyone - including Motor's scribes. A more friendly team would be hard to find.
George, the quiet perfectionist, and Bill the extrovert Champion, make a combination which should be hard to beat in 1971.
|
The Imp Site |
© Franka |