Development of the Hillman Imp

Second hot climate test
(Kenya, 1963 - preproduction)

Part of Kenneth Sharpe's memories

Linwood organised a preproduction car test in East Africa.

The next overseas test was to Kenya (this was a year before their independence) and followed on closely after the Scandinavian test. Cars WHS 156 (L21) and WHS 157 (L22) were, with Linwood co-operation, instrumented and prepared for this test, which we knew would be a tough one. This time boxes of spares were dispatched in advance and engineers from Woodhead, Girling, Solex and Pressed Steel were invited to attend.

Car time on pre-production cars is very valuable so the cars must have been flown to Nairobi, but I cannot remember collecting them - maybe the Linwood lads did.

The first exercise was to check out the cars and their instrumentation.

On higher ground
Running round a road behind the Ngong Hills soon gave the warning that we would have trouble with the back end with frequent light grounding. Otherwise everything worked and we were ready to start determining settings for carburettor and dampers.
At the height of Nairobi (6,000 ft) the shortage of oxygen in the air means the carburettor settings have to be revised. This brings about a drop in power, just at a time when more power would be desirable because of the surface of the roads. This has to be accepted, so with the engine running correctly, work can be started on the damper and spring settings.

Rough roads
Grounding the sump of both cars meant undershields had to be constructed immediately. Derek Sleath, Vic Gorman and the Linwood fitter set to with a will and, using facilities provided by Rootes Kenya, a sump protection undershield was constructed. These enabled some spring rates and damper settings to be determined and we had a good trip (100 miles) down to Hunters Lodge on the Mombasa Road.

Engine temperatures kept rising as the day progressed. Investigation showed some of the fan blades were missing. Flying stones were hitting the inside of the rear cross member and bouncing forward into the fan. Derek, Vic and the Linwood fitter (I wish I could remember his name) spent another busy evening and morning extending the sump guard to include a mesh to keep out the stones.

All the above did not happen in a couple of days as it might appear from this description, together with other problems (like bent track rods) it took the best part of 10 days.
With the cars in reasonable condition we set off on a tour of north-east Kenya. Kisumu, Tororo, Mbale round the base of Mount Elgon and back through Eldoret. Apart from dust entry I can't remember any real problems.

Back in Nairobi we had a days rest. On these tests I always tried to allow one days rest each week and in a place where we could swim or perhaps use one of the cars to visit a National Park. In this way we had two days in Amboseli N.P.; one day dust testing and assessing various air cleaner elements; the other watching elephants, giraffes etc., with the night spent under canvas listening to the lions roar and wildlife noises. That was a good experience for all the test team and it refreshed us for the next spell of intensive work.

Road conditions
Back in Nairobi we prepared for our next run down to Mombassa and on to Tanga. Two very different types of road. Nairobi to Mombassa was, as may be imagined, a busy road with about 60 miles of tarmac out of Nairobi and 30 Miles of tarmac going into Mombassa. The 200 miles of road between were 'muram'. Muram is a surface remade with a snow plough after the rains and where streams crossed the road a 'donga' is formed. Until the heavy lorries cut up the surface it made a fast road with traps for the careless in the dongas, which by their nature formed in a dip in the road, which concealed up to two feet of water or broken down cars or very probably both. If you didn't notice this, hard braking on muram was like braking on ball bearings - exciting! The road on to Tanga was very different, thick sand and there must have been sharp stones, because we had several tyre failures on this stretch. Another days drive back to Nariobi and it was time to pack up.

The conclusions on this test? Well the Imp wasn't really suited to this territory, but we knew an awful lot more about the Imp and its limitations. It needs a sump guard and in some way the oil vapours and leaks must be kept from going in the radiator, where they collect the dust and ruin the marginal cooling. With their roads, a bigger car is a better proposition. Needless to say I didn't put it in those words in my 1963 report.

'You are now entering Kenya' KS3072: Stop for a car check at the side of the road. Part of the test team, L to R: Garry Walker, Derek Sleath and Vic Gorman

KS3074: Another stop on the roadside. Garry, Derek Sleath, Richard Puxted and Vic Gorman.

KS3078: We had to do some filming for publicity. Here Vic wants some local wildlife in the picture. I don't think the film was used.

KS3095: The cars had just climbed the escarpment and we were letting the heat soak to check for vapour lock. Garry, Vic and Bill Mair of Woodheads.

KS3114: A break at 'Hunters Lodge' I think. Garry, Bill Mair and a Pressed Steel engineer.

KS3131: A 'donga' on the main road from Mombasa to Nairobi.

KS3153: A heavy downpour converted a dirt road into a river.

KS3227: Crossing the Equator. Nakuru - Eldoret Road; Altitude 9109 Ft.

KS3240: A brilliant bit of organisation. We had many punctures on the Mombasa Tanga road. Here we have the Technical reps of rivals Girling and Woodheads changing a wheel while our fitter Vic looks on and supervised by the photographer.

Back at Ryton and down to earth, it was necessary to persuade Design that at least some of our findings applied to all Imps. And while it was clearly senseless to make all Imps suitable for Kenya, many of the problems were investigated and where tooling permitted action was taken to correct.
So most of the year 1963 was spent looking into production problems and proving the solutions. By this time, all drawings having been released and tools being made there was virtually a stop on alterations. Even if the solution to a particular problem was known, it could not be introduced, because it would delay production which had to be up and running for the opening of Linwood by Prince Phillip.
I went to the opening day festivities, but I was wondering what the public would make of this underdeveloped car.

All we could do in Development was to investigate problems and hope to have changes made during the production run, as convenient or in a Mk 2. Some of these were difficult, like water pumps. A lot of rig test work was put on in the construction of a multi pump test rig. Many problems of cars at that period were not found on test, because we pushed for mileage and the problems that appear when 'Granny takes the children to the sea for the day and then leaves the car standing for a week until she goes shopping again' are not found with intensive running. The fitter testers tend to drive hard, particularly with a car like the Imp, which thrives on such treatment.

Third hot climate test (Kenya, 1964 - Production & development)

By now the Imp was in production, so two cars were shipped to Mombasa. The first job on arrival in Nairobi was to fly down to the coast to collect the cars. Sump guards and suitable suspension had been fitted at Ryton, so when we got the cars out of customs, we were able to start the drive to Nairobi - well we would be when the road was opened. It was just after the rains and the snow ploughs were still at work.
Then it was up to the big city, where we made ourselves at home in the Rootes Kenya workshops (these people were amazingly helpful - we must have upset the smooth running of their service department terribly).

After the usual round of testing suspension settings for Woodheads and Girling monotubes, carburetion and cooling, we started the first proving run. This was a circuit of Eldoret, Tororo (were we where told that we must wear a tie), on to Soroti, Gulu (later to become the starting point for Idi Amin, and a days rest by the Murchison Falls National Park. After our fill of crocodiles and hippos we pressed on to Fort Portal, Mbarara, Kampala and back to Nairobi. We were pretty pleased with this run, which had taken about a week.

KS3311: After the first week of work time to relax. Harry Harris of Girling and Bill Mair of Woodheads.

KS3339: When this guy inspects the car you don't argue.

The cars required a good check over, cleaning of the radiator, air filters etc., and inspection of suspension and associated parts for damage and cracks.

We had intended to make a similar trip into Tanganyika, as it was then called, but we were advised that the political situation was not good, so we contented ourselves with a run down the Namanga Road and further trips down the Mombasa Road. After one of these drives we found the air cleaner element seal had been damaged and a considerable amount of dirt had entered the engine. While this was investigated, Harry Harris and I did some further work on the Girling monotubes and did a long days drive to Nyeri, across the Aberdare hills to Naivasha and back to Nairobi.

KS3372: Imp with Harry Harris in the Aberdares. (The Aberdares are the third highest range of mountains in Kenya. There is a road which traverses the mountains from Naivasha to Nyeri which can be handled by a sturdy car in good weather. At its maximum elevation the road passes through misty moorlands at about 3350m.)

Harry Harris

KS3377: Another crossing of the Equator. Nakuru - Eldoret road; altitude 9109ft. Reg.: 4105 KV

KS3489: And another - this time in Uganda.

KS3495: A bit of fast climbing in the south of Uganda.

With the end of the test time approaching, we tidied up and left the cars for Rootes Kenya to put some miles on and ship them back to Ryton. And boy!! did they put some miles on. They engaged drivers to drive down to Mombasa, hand the car over to another driver who drove back to Nairobi and so on. When they shipped the cars they had clocked up 10,000 miles in less than a month. Then we found that the drivers had been giving their friends a lift to the sea sometimes. They admitted to travelling 4up, but we cynics wondered if it had become a bus service. Still they had put the mileage on and quicker than we would have managed in this country in those days.

The conclusions for this test were that the Imp had improved since the last test but that it could in no way be recommended for that territory. It was really a car for use on tarmac.