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The Vanwall Grand Prix engines
Part 5: The 'AvGas' 2.5-litre F1 engine

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Who?

Stirling Moss

What?

Vanwall

Where?

Zandvoort

When?

VII Dutch GP (May 26, 1958)

 Stirling Moss, Vanwall, 1958 Dutch GP
Why?

The upcoming 1958 season presented two significant rule changes that would impact on engine development at Vanwall. One was the requirement to use pump petrol and the other was the reduction in race distance from 500km or 3 hours duration to 300km or 2 hours duration.

The first requirement presented difficulties in defining exactly what characteristics pump petrol could have, as pump fuel varied in different countries. So the FIA finally allowed commercial grade Aviation fuel of 100/130PN (AvGas) as the specified fuel, as it was the same in all countries, but they never tested the fuel used by Vanwall.

From an engine perspective, the first impact to be considered was the loss of an internal cooling effect because of the lower latent heat of evaporation of AvGas compared to the alcohol fuels used up till then, this particularly affecting engines with fewer large cylinders.

The second consideration was that less fuel needed to be carried because petrol gave better fuel consumption (having a higher calorific value than the alcohols) and because of the shorter race distances to be covered. Cars could therefore be smaller and lighter and Ferrari had already worked on this with the Dino V6 246 F1 cars used at the end of 1957. Vandervell wasn't going to design new cars or engines but set about modifying the proven racing car he had.

5.1 Engine Development - 1958

In adapting to the new regulations, Vandervell's team considered all manner of ideas such as water injection as used on Rolls-Royce Merlin aircraft engines, the use of three or four valves per cylinder and different camshafts, but they decided to adapt what they already had. Fuel supplier Shell Mex & BP helped by providing an AvGas fuel with an octane rating of 108/135PN which they labelled 'BP/F1/VAN', while numerous other modifications had to be made to the engine.

5.1.2 Fuel Injection

A major part of the work was adapting the Bosch high-pressure fuel injection system to the use of petrol. This involved alterations to the metering cams in the fuel-injection pumps, which was done in the VP tool-rooms as their precision equipment was superior to Bosch's for final grinding on the cams, after which the pumps were sent back to Stuttgart for modification by Bosch.

The interconnected throttle linkage between the air-throttle slides and the fuel-feed rack of the injection pump had to be much more precise than had sufficed before. As it was, at full throttle, regardless of engine speed, the linkage gave the full stroke of fuel delivery from the pump, so that the quantity of fuel injected was not regulated to the mass of air inducted by the engine. This meant that the air/fuel ratio was variable and didn't allow for the effect of resonance, scavenging or cam timing, so that while the mixture was correct at maximum volumetric efficiency (around 6,000rpm) it was very rich at peak rpm, where breathing tailed off. This was not a problem with alcohol fuels which can tolerate a wide range of mixture strengths (beyond the average 1:8 used) without loss of power. However, with hydrocarbon fuels (petrol) the range of mixture strengths between weak and rich, so as to obtain maximum power and good burning without detonation or plug fouling, is very much narrower (the average is about 1:14 and maximum power is about 1:12). The existing set-up would have caused a loss of power at maximum rpm.

Much work had to be done on the linkage so that the pump stroke was reduced at peak rpm. To try and address this, Vandervell evolved an additional slip link in the control linkage that allowed the fuel rack to return back a little from full rich to give a weaker mixture strength at peak rpm. One plus from all of this work adapting to hydrocarbon fuel was that it took out a flat spot that had occurred at around 5,000rpm on sharp acceleration which Moss described as "cutting in and out as though one was switching the ignition on and off" and this gave better throttle response.

5.1.3 Cylinder Head and Pistons

Careful attention to piston crown shape, port shapes and valve timing was carried out to try and minimise the loss of power on petrol. Bigger inlet valves with a head diameter of 53.6mm and 9mm diameter stems were fitted (these were sodium-filled, as introduced late in 1957). The sodium-filled exhaust valves were 45.4mm in diameter. The inlet and exhaust throats were 49.5mm and 41.3mm diameter, respectively.

Various different valve timings were tried in testing, opening and closing the inlet valves 10°-12° later, but the standard valve timing used was:

Inlet valve lift was 13.5mm, held for 47% of the total lift phase of the cam.

Note

An interesting comment was made in The Autocar magazine of 1-1-1960 regarding Vanwall cam profiles in an article reviewing the new seasons cars, Harry Mundy was technical editor at the time. ”Vanwall had still not overcome its valve breakage problems. Perhaps by now Mr. Vandervell has realised that quieting ramps on the cams to reduce the valve seating velocity were not used on the Norton cams, from which the Vanwall cam form is developed“ (An observation with all due respect is that the Vanwall valves were much larger than those in the Norton and perhaps that is why VP used quieting ramps?)

The valves weighed approximately 120grams for the inlet and 116grams for the exhaust. When the weight of the short 'pushrods', cotters and collars were added to the total, the reciprocating weight of the inlet train was about 180grams, so the valve springs were severely tested at max rpm when cycling at over 60 times a second. The lift to inlet valve diameter ratio was 0.25, giving ideal maximum flow area.

The piston was reshaped with a flatter crown and the highest compression ratio that was possible without detonation was 11.5:1. To prevent piston overheating following the loss of the cooling effect of the alcohol fuels, a system of jets spraying oil onto the underside of the pistons was developed and it worked well.

5.1.4 Exhaust System

The exhaust system was altered from the equal-length arrangement feeding into a collector as used before to a more effective extractor arrangement similar to that used by BRM. The primary pipes were much shorter, merging the cylinders in the same grouping as before (i.e. 1 and 4; 2 and 3) into two pipes closer to the engine. These two secondary pipes were of similar length to the primaries and led out of the bonnet to merge into the tail pipe, that was much shorter than before and ended alongside the cockpit. The end of the tail pipe was enclosed by a larger diameter sleeve that fed the gases to the rear and in creating an annular space around the end of the tail pipe gave a small extractor effect itself.

5.1.5 Lubrication System

The horizontal de-aerating tanks fitted at the end of 1957 were initially retained in 1958 but by the Belgian GP in June had been replaced by a tall cylindrical de-aerating tower mounted on top of the oil tank and in front of the transverse chassis tube (similar to that used in 1957 before the Moroccan GP, but taller). This meant that the engine's hot-water offtake pipe could again be connected directly to the radiator. The filler for the oil tank was still on the left-hand rear corner.

In the never-ending quest to control high oil temperatures, at the next race, the French GP, the Vanwalls had new taller L-shaped oil tanks mounted directly behind the radiators with the lower wide base of the tank filling the space beneath the chassis cross tube as before. The vertical section was in front of the chassis tube and extended up to under the bodywork and had the filler cap on top, where it was accessible via a hinged flap in the bodywork. This arrangement increased the oil-tank capacity and did away with the need for a separate de-aerating tower. It was used for the remainder of the season. Oil-cooling arrangements are described in the next part.

5.1.6 Cooling System

The loss of the cooling benefit of alcohol fuel also taxed the car's cooling system and the engines ran hotter, with temperatures around the valve seats increasing by as much as 200° C. The cylinder heads also suffered from a problematic high thermal loading, in part because of their shallowness and relatively low mass. The radiator was the same three-element format as before with a thermostat and cowl-mounted water header tank, although the core was increased in size. But the cooling system was marginal and as the year progressed further changes were found necessary.

For the Portuguese GP in August, a substantial change was made to cope with the high summer temperatures and combat the engines high oil temperatures. The whole of the radiator core was given over to cooling the engine's water and a separate film-tube-type oil cooler block serving both the engine and gearbox was mounted on the top of the car's nose, supported by a tubular structure above the main radiator. It was enclosed in a streamlined duct that created a bulge in the smooth bodyline of the car and through which air entered and exited over the bonnet after flowing through the oil radiator. Frank Costin was again consulted to ensure the duct was functional and created minimal additional aerodynamic drag. This arrangement lowered the water temperature markedly, but oil temperatures were slightly higher (there was now no heat exchange with the water) and this setup was retained for the following Italian GP. The oil-tank filler cap was still accessed via a flap in the bodywork behind the duct.

For the final race, the Moroccan GP ,this separate oil cooler was discarded and the original three-element radiator matrix (engine oil, engine cooling water and gearbox oil) was again installed.

5.1.7 Engine Output

The work undertaken meant that the power loss converting to AvGas was limited to about 7% (from285bhp down to 265bhp) while the drop in peak torque was approximately 6%, but this was partly offset as the car had been lightened by about 25kg from work done over the winter. As stated, the development had removed the previous flat-spot at 5,000rpm, but the rpm range from peak torque to peak power was reduced from 21% of peak power rpm to only 17%, making the car more difficult to drive on twisty circuits.

A VP power curve of engine V4 taken before the 1958 German GP showed:

(Weslake was also helping BRM to adapt its engine to AvGas and in a report to BRM he stated, ”as air flow figures are now considerably in excess of the Vanwall engine, combustion must be a problem” - no confidentiality there?)

5.1.8 The Competition

1958 was effectively a battle between Vanwall and Ferrari, with privately entered 1.96-litre and 2-litre Coopers taking two surprise wins. Ferrari fielded its powerful Dino 246 F1 V6 car with Hawthorn, Collins and Musso on the team. BRM showed real promise and Lotus entered F1 with the type 12 and the 'mini-Vanwall'-like Lotus 16, both powered by 1.96-litre and 2.2-litre Coventry Climax FPF engines as available. The works Coopers were similarly powered.

Maserati had withdrawn from works racing at the end of 1957 due to financial and other difficulties, but developed a lighter T3 'Piccolo' 6-cylinder 250F that saw limited racing, Fangio using it for the final race of his career at the French GP.

5.1.9 Vanwall Race Performance

Following endurance test-bed running of the engines on AvGas, the first long-distance track testing was carried out at Oulton Park and Silverstone in mid-January 1958. Vandervell had chosen to miss the first Championship race, the Argentine GP on 19 January which was won by Moss driving a rear-engined 1.96-litre Cooper-Climax.

Work on the Vanwall had lightened the chassis wherever possible and the shape of the tail had been re-profiled by Costin. The first of these completely revised cars was tested by Moss at Silverstone at the end of April. Engines running on AvGas were now standing up to 12-hour runs on the test-beds and the decision had been made to only contest the remaining events counting towards the Manufacturers and Drivers Championships.

So the first race entered was the Monaco GP on 18 May, but during final pre-race engine testing engine V3 would not produce the sign-off power of 265bhp at 7,400rpm +/- 1% that was required. The transporters left for Monaco while engine V3 was worked on at Maidenhead. The engine finally produced the required power and was put on a BEA freight flight to Nice but was destroyed when the plane crashed in bad weather (reportedly the crankshaft was salvageable); not a good start. Brooks was on pole alongside Behra's BRM while Moss and Lewis-Evans were on the third row behind three Cooper-Climax cars. At the start Behra took the lead in the BRM with Brooks second until he had to retire on lap 21 when a stripped thread caused a spark plug to blow out of the cylinder head. Behra retired and Moss took the lead on lap 33 but then he retired on lap 38 with valve-gear trouble (a rare fault, a valve cap came off). Lewis-Evans had retired on lap 12 when a warped cylinder-head joint failed and pressurised the cooling system again. Trintignant won the race in a 2-litre Cooper-Climax.

In the Dutch GP on 26 May, Vanwalls filled the front row of the grid, Lewis-Evans on pole. Moss led off to win convincingly despite limiting his revs to 7,200rpm because of sagging oil pressure in right-hand corners. Brooks retired on lap 13 with handling problems while Lewis-Evans retired on lap 46 with a broken valve-spring holder.

In between races, work continued in the search for more power, the inlet and exhaust valves had been steadily increased in diameter (the inlets up to 54.9mm) but this brought problems with the weight penalty of the larger heads and breakages were frequent. In addition in the search for better breathing, valve lift was increased (to 14mm) and different valve timing tried. The valve-to-piston clearance was minimal so that adherence to rev limits was critical. Norman Burkinshaw, one of the head mechanics, stated that as the valve heads got bigger they were too much for the stems and would break off. He felt that the sodium-filled inlet valves weren't necessary, but Vandervell wanted them, so they had to persevere.

The next event was the Belgian GP on 15 June at Spa-Francorchamps. In practice, Moss chose 16-inch wheels rather than the normal high-speed circuit 17s and was easing back at 7,400rpm on the straights and seeing 7,000rpm on the uphill run after Stavelot. Hawthorn set pole at 3.57.1, with Moss third fastest, 0.5 seconds slower. Brooks qualified fifth, with Lewis-Evans 11th. The start was delayed and the Ferraris were worst affected with rising temperatures and falling oil pressure. Moss was out on the first lap just as he took the lead when he missed a gear-change at peak revs and bent the valves. Brooks took the lead and battled with the Ferraris to win the race even though near the end the oil pressure was dropping. The engine was okay but the gearbox take-off was dangerously low. Lewis-Evans finished third. In the race the Vanwalls showed more power on the long climb up from Stavelot but the Ferraris with their higher top speed easily passed them on the downhill straight to the Masta kink.

The engine in Moss's car at the Belgian GP had some development changes, most significant of which was the altered triangular bolt pattern on the exhaust port flanges. Previously the flange had two bolts at the top and one at the bottom but the pattern was now rotated, placing one bolt at the top and two at the bottom, giving more space for the ends of the hairpin valve springs. This pattern was adopted for the rest of the season as head castings were modified. The other change was only for this race: the exhaust-cam drive housing was fitted with a breather hose which connected forward to the de-aerating tower on top of the oil tank.

Valve breakages, particularly of the large sodium-filled inlets, were a constant problem, exacerbated by the manufacturer's insistence on filling both the inlet and exhaust valves from the head end, necessitating discs welded into the heads to seal them and the hollow stems. Vandervell took the valve manufacturer, Motor Components Ltd. of Coventry, to task over their product and relationships broke down to the extent that the company suspended all work for VP until Vandervell apologised.

This wasn't going to happen given Vandervell's strong temperament, so Vandervell looked elsewhere for a valve supplier, only to find that the Managing Director of Motor Components Ltd. sat on the boards of the majority of valve-making companies in the Midlands. Motor Components produced a solid nimonic valve which Burkinshaw stated would have been suitable but Vandervell wouldn't consider using them.

Some small firms in the south of England were found who could keep them supplied with valves but they were not satisfactory, so while the season progressed a difficult and challenging programme was set up for VP Ltd. to make their own valves from scratch. This was not straightforward, as the sodium-filled valves had to have hollow stems and the heads were very large in proportion to the stems. But VP's engineers succeeded, importing machinery from America to aid manufacture and by the end of the season they were becoming independent of outside suppliers. They had even developed some experimental lightweight valves that were safe to 7,800rpm without a hint of trouble (these were used in a 1985 rebuild of engine V8 by ex-VP personnel for a rebuild of chassis VW11).

The French GP at Reims was on 6 July. Hawthorn set pole time with two more Ferraris and a BRM qualifying ahead of the Vanwalls of which Brooks was fastest, 1.7 seconds slower than Hawthorn's time of 2.21.7. In the race, Hawthorn led from the first lap and went on to win for Ferrari, with Moss second, his car having a misfire between 6,400 and 6,800rpm and unable to match the power of the Ferrari, being almost 10mph slower in straight-line speed. Fangio in a 250F Maserati driving his last race duelled with Moss and Behra to finish fourth while Brooks retired with valve problems and took over Lewis-Evans's car only to have engine failure, a broken inlet valve. In practice, with the Vanwalls running longer at full throttle than ever before, there were a lot of problems with cylinder heads warping due to the higher engine temperatures resulting from the use of AvGas and two engines dropped valves, needing to be rebuilt for the race. The cars were fitted with new taller oil tanks that could be filled via a flap in the bodywork (see part 5.1.5).

Ferrari also won the British GP at Silverstone on 19 July, Peter Collins the victor this time. Moss was fastest in practice and took pole (he was pulling 7,300rpm in 5th down to Stowe) but Brooks was slow and his car was taken back to Acton to have the head lifted and the valves ground in, but it didn't fully regain its speed. With the two engines blown up at Reims, Vanwall was in difficulty. In the race, Collins passed Moss on acceleration out of the first corner and then was never challenged for his win. Moss retired with a broken valve on lap 25, Lewis-Evans finished fourth and Brooks seventh, neither ever a threat.

Experiments continued at Maidenhead on the test beds, trying different materials and construction to try and resolve the problems with valve breakages, but there were some disastrous results which took a heavy toll on cylinder heads, causing a shortage of engines, not helped by the engine failures in the previous two races.

So for the next race, the German GP on 3 August at the Nürburgring, only two cars were entered, for Moss and Brooks. The Vanwalls' roadholding and handling was much more suited to the circuit than the disaster of the previous year and they were second and third on the grid, with Hawthorn's Ferrari on pole. Moss took the lead at the start and was lapping comfortably, using only 7,000-7,100rpm, when his magneto shorted out on lap 4 and he retired. Brooks took up the chase of Collins and Hawthorn and although the Ferraris were faster on the straights and had better acceleration he was able to gain on the back part of the circuit and out-braked them one after the other to take the lead and go on to win.

The Portuguese GP at Oporto on 24 August was next and Vanwall was back to three cars entered, all fitted with separate oil coolers on top of the nose cowling in an attempt to reduce engine temperature (see 5.1.6). Moss was on pole using wide-spaced gear ratios and running up to 7,200-7,400rpm (he recorded a water temp of 70° C and oil temp of 90° C with a constant pressure of 45-50psi). Hawthorn was second fastest and Lewis-Evans third, with Brooks fifth on the second row. Moss and Hawthorn battled for the lead until lap 8 when with the Ferrari's brakes fading Moss pulled ahead and went on to win comfortably. Lewis-Evans finished third but Brooks spun and stalled the engine and had to retire.

At the Italian GP at Monza on 7 September, Ferrari had fitted Dunlop disc brakes to Hawthorn's car in place of the usual drums. Vanwall took the cars direct to Monza from Oporto, while the engines were flown back to England for attention. The Vanwalls were fitted with 700x16 rear tyres and still had the oil coolers on the nose as at Oporto and in practice Moss tried a perspex bubble canopy over the cockpit, but it only gave an increase of 50rpm on the straights and he decided not to use it in the race. During practice Moss missed a shift and bent a valve requiring an engine change. He then tried a lower final-drive ratio and was quickest using 7,000rpm in 4th through the Curva Grande. Brooks qualified second fastest with Hawthorn and Lewis-Evans completing the front row. In the race, Moss battled Hawthorn for the lead only to retire on lap 18 with a seized bush on the gearbox main-shaft, Brooks pitted on lap 15 because of an oil leak from a burst driveshaft gaiter, but nothing could be done so he continued on to judge his speed to finish without a tyre change. Lewis-Evans had the fastest Vanwall on the straights but the high-speed running took its toll and he retired with over-heating caused by a leaking head joint. Hawthorn pitted for tyres and came out just in front of Brooks, but his Ferrari was suffering from clutch slip and although the Ferrari was faster on the straights, Brooks was able to slipstream it and get a tow past into the Curva Grande and then go on to win.

Vandervell pressured the VP research department to investigate Moss's gearbox failure and it proved to be a lubrication problem with the oil supply from the engine pressure bleed-off.

But Vandervell had a lot to be pleased with, for although there was still one race to be run in the championship, his Vanwalls had secured the first post-war Manufacturers World Championship for him, with a points score of 46 that nearest rival Ferrari could not better, even if they won the last race (Vanwall's final score after the last race was 48 to Ferrari's 40).The drivers championship was still open.

The final race was the Moroccan GP on 19 October at Casablanca and the Vanwalls were modified by removing the nose-mounted oil coolers and going back to the original three-segment radiators cooling water and oil (see 5.1.6). In practice the cars still suffered from high engine temperatures and Moss's engine dropped a valve and had to be replaced. Hawthorn was on pole 0.1 seconds ahead of Moss, then Lewis-Evans, Brooks was on the third row. For Moss to win the drivers championship, he had to win and set fastest lap with Hawthorn no better placed than third. Moss did his part but Hawthorn finished second with help from his team mates and thus became the World Champion. Brooks retired on lap 30 when his engine suffered valve failure and Lewis-Evans crashed on lap 42 when his engine seized and sadly suffered severe injuries from which he died six days later. Vandervell was deeply affected by the death of one of his drivers and it weighed heavily upon him. In addition, the pressure of running his business and his Grand Prix team was enormous and had taken a toll on his health.

He had won the World Manufacturers Championship but at a high cost. Development and experimental work continued back at Acton and Maidenhead in preparation for racing in 1959, but on 12 January 1959 Vandervell issued a statement declaring that on medical advice he was closing his team down.

5.1.10 1958 in Review

5.2 Engine Development and Performance 1959

Notwithstanding his announcement that he was retiring his team of cars, Vandervell did not give up completely. There were staff cutbacks in the racing team, but key personnel were still there and there would be a few sporadic appearances before the team was finally shut down. His beloved four-cylinder GP engines were kept running on the Maidenhead test-beds doing development work on engine research. One significant development that was produced after the team racing finished in 1958 was cylinder barrels that screwed into the cylinder head, finally solving the problem of fire-joint sealing, but it is not known whether these were used in the final few race appearances that would occur. (This mirrored the practice used in the Lampredi-designed Ferrari V12 engine in the last ThinWall Specials.)

Vandervell had offered Tony Brooks a retainer to stay with the team in case he decided to resurrect it, but Brooks didn't accept and signed up with Ferrari for 1959. Nevertheless, VP continued with some development work on the car and when a workers strike at the Ferrari factory prevented an entry by Ferrari in the British GP in July at Aintree, Vandervell told Brooks he would prepare a Vanwall for him to drive in the race. The car, VW5, was to the same general specification as the 1958 version, except that the engine, propeller shaft, seating position and bodywork had been lowered and a little weight removed. They had also worked on the engine and increased torque through the range. Brooks accepted but found the car was not a shadow of the racing car he had driven in 1958. Even a team as professional as Vanwall could not suddenly gear up and be competitive.

In practice Brooks had problems, the fuel injection had always required the most delicate adjustment to eliminate flat spots and he found the engine's performance well below par. With the wider torque band, the engine should have pulled a higher gear ratio but proved unable to do it. The best he could manage was the third row of the grid with a time over four seconds slower than the time he did in 1957. In the race, the car was completely outpaced and a misfire developed. Brooks had to retire. Vandervell had a new Leyland-articulated transporter-cum-workshop at this race, his intent was still serious.

Vandervell instigated a full investigation into the car's poor performance and apart from a magneto problem it was found that when the bodywork was modified the air-intake box had been altered, causing a loss of power.

Vandervell could not let go of racing completely and development continued on the front-engined car. He contacted Brooks again and said he was also working on a new rear-engined car for 1960 and wanted to retain his services for testing and racing when the car was sufficiently developed. This time, Brooks accepted.

5.3 Engine Development and Performance 1960

In 1960 Vandervell produced VW5 again for Brooks to drive at Goodwood's Glover Trophy on 18 April but the car was uncompetitive and he finished seventh. The engine air box had been reinstated to its original proportions and sat proud of the slimmer bodywork but lacked the aerodynamic integrity of Costin's earlier concept. Brooks stated that he felt Vandervell was wasting time working on what was basically a 1958 design and that they should concentrate on the rear-engined car.

In the meantime, Vandervell had gone to Lotus and purchased a rear-engined Lotus 18 chassis (no.901) into which they had fitted a Vanwall engine mated to a Lotus gearbox. Several weeks after the Goodwood race, Brooks tested it at Snetterton. But the program seemed to stall, as work focused on the front-engined cars.

Vandervell had engaged Valerio Colotti of Modena, Italy, to design a 5-speed gearbox and independent rear suspension for a front-engined Vanwall and to also help design a rear-engined car. To facilitate this, Colotti went to Acton to work on the projects. After its Goodwood appearance, VW5 was used to test the new independent rear suspension. Then it was broken up to provide parts for the new 1960 front-engined car incorporating Colotti's designs, the VW11. This was dubbed the 'low-line' car and was a highly modified design, significantly lighter and much lower with less frontal area, as the Colotti gearbox was not under the driver's seat as before but projected to the rear of the final drive. This allowed a lower tail shaft and seat.

The engine was developed to reportedly produce almost 280bhp but no details of how were released. The only visible changes were to the exhaust system which exited the side of the engine bay and terminated low down just before the rear wheel. It had a revised top to the engine oil tank to fit the lower body profile.

The new car was entered in the French GP at Reims on 3 July for Brooks to drive, but a less powerful engine had been fitted. In practice, the Vanwall had problems with the adjustment of the fuel-injection controls and difficulties with the oil-scavenging system. On the final day of practice a detached magneto-earthing wire caused delays and Brooks's fastest lap was only a tenth of a second faster than the time he had recorded in 1958. The car was up to 17mph slower on the straight than the old one due to poor airflow over the lower body, negating any improvements. A striking indication of the lack of progress made, especially as he was 6.5 seconds slower than pole position. Brooks was on the sixth row of the grid and at the start got hit by another car. He was further troubled by severe vibrations, in part he felt down to the lack of testing on full tanks and the affect it had on the halfshafts' angularity and sliding joints and the car was retired for safety reasons on lap 8.

The final appearance of the 2.5-litre engine was in practice at Snetterton in September 1960 for the Lombank Trophy, in rear-engine configuration in the Lotus-Vanwall, as detailed in the next part.