4.5 LITRE FERRARI

The Roycrofts' next car was a 1952 4.5 litre Ferrari, a V12 with one camshaft per bank of cylinders, dual ignition, three double choke carburettors, De Dion rear suspension and drum brakes. This car did not prove really successful and their choice came in for criticism. It should be remembered however, that at the time, the Thinwall Special Ferrari was one of the fastest cars in Europe and held the lap record on many English circuits. Perhaps what was not realised was that the circuits in N.Z. were mostly slower than in Europe, so that the full performance could not so easily be used to advantage and that much work would be required to keep it running. It did have Parnell and Whitehead concerned, as they knew that if it went well, no cars they could bring out would be able to beat it.

The car purchased had done a lot of racing and was not in good condition. Although spares were obtainable the price of some was prohibitive. The Thinwall Special had of course been run by the bearing manufacturer of the same name and was used for disc brake testing; as a result all necessary resources had been available.

To do a complete overhaul on this complicated car would take more time than I had to spare; therefore the job was split up with Ron doing the motor and I the chassis and transmission. This gearbox was not as sturdy as that fitted to the smaller three litre Monza Ferrari I was to work on the following year.

Roycroft's ex-Rosier GP Ferrari arrived with an all-enveloping body which had been fitted for sports car racing. A new single seater body was built by Johnny Morrall, who copied photographs of the original and did a very good job.


1952, 4.5 Litre, V 12 Ferrari. With sports body, as imported and run at Mairehau, 1956.

The first race was the 1957 N.Z.I.G.P. at Ardmore, which was also the first major event for my new Lycoming Special. One of the difficulties with the Ferrari became evident on the first practice day, when after a few laps to warm the motor, the pit crew set to work to change to racing plugs. By the time the 24 plugs, some of them in hard to reach places beneath the carburettors were changed, practice time was over. The following day Ron got going well and made the second fastest time of 1 min 29.2 secs.

In the race he made a fast start from pole position and got into a fair lead, the big Ferrari accelerating away from the opposition out of the corners. After about ten laps, he began to be affected by heat and slowed, later retiring due to heat exhaustion. Many thought that Ron was not fully fit having spent too much time in the sun the day before, but this was not the complete answer.

In the next race at Wigram, Ron again took the lead on the first lap, but soon once again began to feel effects of the heat. This time he managed to keep going by hanging his head out to one side into the air stream, and he finished in third place.

As a result of this experience, a large air scoop was fitted to ventilate the cockpit and the Ferrari no longer overheated its driver. Those who have not experienced this situation may find it surprising just how warm it can become, sitting close behind a 200 to 400 horse power engine.


Ron Roycroft driving the 4.5 litre Ferrari, 1958.
Note the vents added to the sides of the cockpit, as well as the extra cockpit vent, just visible ahead of the aeroscreen.

At the following Dunedin round the houses race, Ron again took the lead on the first lap and this time held it, until he retired on the 15th lap with transmission trouble.

Next came a race at Ryal Bush with its long straights, which seemed to offer the best opportunity for the big Ferrari to show its performance. After practice on the morning of the race, Ron took the sump off for a quick inspection. His reaction indicated that things looked rather ominous, but he said nothing and simply replaced it. I was to find out later that he had taken a gamble, trusting on providence. It transpired that only two of the seven main bearings were intact by the end of the coming race.

At the start of the race there was a mix up at the first corner when the four fastest cars arrived together, with Gould and Ron going down the escape road. Ron lost half a lap restarting, but soon worked up to fourth place, his third lap was timed at 2 mins 12.4 secs, compared with Parnell's best of 2 mins 11.6. He then settled down to lap about two seconds slower than the leaders until near the end, when he slowed considerably to finish with the engine in rather bad shape. In this race Ron, with very little time to practice, was driving at higher speeds than ever before against drivers to whom 170 m.p.h. was normal.

Of the four races, the first two had been spent learning that there was a cockpit overheating problem. Mechanical failures and the first corner incident spoiled the second two.

Roycroft's was not the only Ferrari to finish the season in trouble. Parnell and Whitehead had known about the 4.5 litre car being in New Zealand for about a year and probably asked Ferrari for the best cars that he had to compete against it. They had been supplied with two new Super Squalo Ferraris, fitted with 3.5 litre four cylinder DOHC engines producing near 300 h.p., or about 100 less than Roycroft's car.

After the Ryal Bush Race, Tom Clark took over Peter Whitehead's car. After a good win at Mairehau and another at Levin, his season ended with some expensive noises.

Whitehead's mechanic, who had been keeping an eye on the car, had a quick look at it and departed for England, saying he would bring back the necessary parts next year, so Tom carefully put the car away.

When the next season was getting close and with no mechanic or parts in sight, I was asked to come and help Tom's pit crew dismantle the motor. When we lifted off the cylinder block, a shiny piece of aluminium about the size and shape of a hen's egg, dropped out. It seemed unbelievable that this was the largest remains of one piston. As could be expected there was considerable associated damage.

I was at the time busy rebuilding the 4.5 litre motor for Ron, therefore Tom asked me who could I recommend to fix his car. Hec. Green seemed the best choice, and Tom lost no time getting him up from Christchurch. Hec. got it all sorted out and went over to Australia with Tom for a few races. Tom had a crash at Bathurst when a slower car got in the way and spent a period in hospital. During his convalescence, the Ferrari was repaired and fitted with all the improvements, including nitrided liners, that Hec. could think of while utilising the facilities of Repco that he had at his disposal.

When Ron examined the V12 motor after the Ryal Bush race, he found cracks in the crankcase around most of the main bearings. What is more the five centre caps had come away, pulling the studs out together with bits of the crankcase. My reaction was to suggest a new motor, but the cost put this out of reach. A few weeks later, Ron arrived with a welded up crankcase and it looked like quite a good job, having been done by Cains Welding Works. He questioned me as to whether I would carry on from here and put it all together.

The crankcase was stress-relieved in an oven at the Colonial Ammunition Company, and then the three main faces were planed on a machine at the Naval Base. After fitting bearing caps and new studs, I spent half a day at Eric Paton's workshop helping to set it up on a line boring machine, so as to machine the new bearing shells and also face the ends. Thus the crankcase was completely re-machined, except for the bores for the wet cylinder liners, from which a few high spots were scraped by hand. Packing was subsequently placed under the cylinder blocks to make up for the material machined off.

Surprisingly the crankshaft was not cracked but needed a regrind. Nitrided shafts are prone to heat checking when being ground. Although every care was taken, and the best wheel available used, this shaft showed many tiny cracks when afterwards magnaflux tested. However, as these cracks ran along the shaft rather than across it, they were not expected to start fatigue cracks.

The cylinder heads were showing signs of distortion around the valve seats. Some of these had been replaced the year before and were again loose with aluminium shavings underneath, indicating that they had been fitted too tight. I knew this to be true, as Warren had told me that when he was helping to fit the seats with the use of the baker's oven, they would not go into place and A. J. Roycroft, after losing patience, had swung a heavy hammer!

Two new cylinder liners were made, these being of the type screwed into the head and therefore required a special tool, i.e. a six foot bar wielded by two men to tighten, according to instructions from Ferrari. I had enquired for the torque figure for tightening, but apparently they had none. Ron later told me these liners were usually found to be loose when a head was taken off. I suspected that this was due to expansion or distortion of the head, as we could not have tightened them any more without causing damage.

When checking over the connecting rods, I noticed a suspicious line in one of the recesses for the bolt heads. I gripped the rod in a vice and gave a tug on the end and behold I had two pieces! This made me very sure that the car had come very near to having a hole in the crankcase during the last race. Ron later told me he had suspected one rod and had had it magnaflux tested twice, but it passed OK. I wondered if the crack had been present at the time but not detected.

The testing of car parts may not always be as reliable as the testing of aircraft parts where the methods of magnetising, currents and likely crack positions, are usually specified in the overhaul manual. Without this information much depends on the skill of the operator, and in some places it can be difficult to tell a crack from a tool mark.

As Ferrari would only supply conrods in sets of twelve at a very high price, it was necessary to make a replacement. Several blanks were forged to get the best grain structure, then heat treated by the D.S.I.R., who had been giving advice. The best was then machined.

Altogether, the rebuilding of this complicated V12 motor involved a great deal of work and I would think about 120 hours would be required to dismantle, inspect and reassemble, provided no work was required on any parts.

Another problem associated with the car was the brakes. The drums were of a light alloy with pressed or shrunk in steel liners, which were also held by screws. The repeated heating and cooling had shrunk the liners, which had as a result lost contact with the alloy. Ron asked me to make new liners, but after much thought I could find no material which offered much prospect of success. I could only recommend that he buy new drums made by the Alfin process, in which a cast iron liner is bonded to an aluminium alloy drum. I was a little shocked when the manufacturer of these suggested that brake drums on such a car, should be regarded as expendable the same as the brake linings, a very expensive thought. This was easy to believe as I had seen Alfin drums from a racing sports car, where the liners had lost their bond with the aluminium and were loose by near an eighth of an inch.

It could be a mistake to use the best modern brake linings, capable of operating at 550C, in these drums made of an alloy and which lose strength at about 250C. If linings which faded at this temperature were used, the drum temperature might be kept down and so increase their life. Of course it would then have to be accepted that the car might not then stop well enough to be able to win the race!

I had found a better solution to the problem when deciding on the drums for the Lycoming Special, but they had been tested in only one long race. In any case, finding such drums of suitable size for the Ferrari, would have been very unlikely.

Ron continued to race the car, but the fast Ryal Bush circuit was no longer in use and during the next three years improved cars were used by the leading drivers from overseas. These were smaller and lighter, with greater braking power and higher cornering speeds, so that the big Ferrari became less competitive. It also continued to suffer mechanical failures in about half of the events entered. In the end it proved difficult to sell and eventually the motor went to Australia, to be fitted into a racing boat, and the chassis to a builder of specials.

The 4.5 litre V12 Ferrari was probably developed to the maximum power that the engine structure and transmission would take in order to compete in Europe with the 1.5 litre supercharged Alfa Romeos. Perhaps it was approaching what used to be said was the correct design for a racing car, i.e. that it should last only long enough to cross the finish line first, in the one race entered, before falling apart through fatigue. In European races the works team had 32 percent of the 4.5 litre Ferraris they entered retire with mechanical troubles.

The parts of the Ferrari were later gathered together by Gavin Bain and restoration was completed in Christchurch by Auto Restorations. Gavin drove the car carefully in classic races for a few years, subsequently selling it to an overseas owner for a considerable sum of money.


1951, 4.5 LITRE FERRARI.

SPECIFICATIONS

Wheelbase : - 92 inches.

Track : - 51 inches.

Frontal Area : - 10.75 sq. ft with driver.

Weight empty : - 16 cwt.

Weight on the starting line : - 20.75 cwt.

Tyres : - 600 x 16 front, 750 x 17 rear.

Brake drums : - 14 x 2.25 inches.

Front Suspension : - Unequal length wishbones with transverse spring.

Transmission : - Four speed gearbox in unit with and forward of final spur gear drive.

Engine : - V12 with single overhead camshafts and rockers, hairpin valve springs, dual ignition with 24 plugs and one magneto, seven bearing nitrided crankshaft. Bore 80 m.m Stroke 74.5 m.m.

Horse Power : - 380 to 400 at 7,500 r.p.m.

Horse power per sq. ft of frontal area, 32.3.

Horse Power per ton, on starting line, 366.


COMPETITION RECORD

Ex Works Team Car, driven by Gonzales and 1951 British G.P. Winner. Then raced by Louis Rosier of France, fitted with a sports car body, before coming to New Zealand for Ron Roycroft

4/02/56 Mairehau : - Retired on start line with clutch trouble. At this time the car was fitted with a sports body as imported and had not been overhauled.

12/01/57 N.Z.I.G.P. Ardmore : - Led in the early stages but retired after 61 laps due to driver suffering from heat exhaustion. Lap time, 1 min. 29.2 secs.

26/0l/57 Wigram Trophy Race, 150 miles : - Led for eight laps, again the driver troubled by heat and finished third. Lap time, 1 min. 27 secs.

02/02/57 Dunedin Road Race : - Led from first lap but retired at 15 laps with transmission trouble. Lap time 1 min, 33 secs.

16/02/57 N.Z. Championship Road Race, Ryal Bush, 100 miles : - finished fourth with broken bearings.

11/01/58 N.Z.I.G.P. Ardmore, 150 miles : - Placed third with a jammed selector and unable to use lower gears.

18/01/58 Levin Races, 8 laps : - Two firsts and a second place in three races.

25/01/58 Wigram Trophy Race, 150 miles : - Pit stop with locking brake and finished at slow speed.

01/02/58 Dunedin N.Z. Championship Road Race : - retired after two laps.

08/02/58 Teretonga Park Races : - Handicap, 12 miles, placed eleventh. President's Trophy, 60 miles, placed fifth.

15/02/58 N.Z. Hillclimb Championship, Clellands, Timaru : - Placed fourth.

01/03/58 Ardmore, 50 mile Race : - Placed second.

09/01/60 N.Z.I.G.P. Ardmore, 150 miles : - Placed twelfth. Pit stop, Engine misfiring. Lap time, 1 min. 27.9 secs.

21/01/60 Wigram Trophy Race 150 miles : - Placed tenth. Engine misfiring. Lap time, 1 min. 32.2 secs.

30/01/60 Dunedin Race : - Retired after three laps with bearing trouble.

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