The Bugatti was back in my workshop a year after I had worked on the original engine, to have a Jaguar engine fitted. This had been ordered from England by Ron Roycroft's father, “A. J.” after their encouraging 1951 season with an XK120 Jaguar, but delivery of the engine had taken about two years. With the XK120 Ron had won the N.Z. Championship Road Race at Mairehau and secured places at Ohakea and Wigram, against George Smith, GeeCeeEss special and Moore, P3 Alfa Romeo.

There was a very dicey incident near the end of the Mairehau race. Ron was following Moore down the straight at about 100 m.p.h. Moore touched wheels while passing a Ford V8 special and the Alfa went into a slide on the loose verge of the road raising a cloud of dust. Ron could see a falling telegraph pole above the dust cloud, but with worn out brakes could not stop and went into the dust expecting to hit something. When he came out, the road was clear of cars and he continued the lap to finish the race.

The Alfa had slued back across the road in front of the V8, hit the pole which broke off, then continued through the hedge and overturned. Miraculously Moore was thrown out unhurt. The Alfa suffered a bent front axle, a broken kingpin and a few dents. I was to find out later that it had a very strong front axle beam and also tended to wander and weave all over the road so that the incident was not really surprising.

Above - Bugatti engine bay with the original engine.
Below - The Jaguar engine fitted so as to create the Bugatti Jaguar Special.

Note that the engine is fitted well to the rear so as to improve weight distribution, and also the reduction in available cockpit space.
The radiator shell was adapted from a Whippet.

Coming back to the Bugatti; the original crankcase was rigidly mounted, acting as a torsion member to keep the chassis from twisting, so the Jaguar engine was fitted the same way. A 3/16 inch steel plate, inserted between the crankcase and clutch housing, formed the rear mounting. It was evident that the Bugatti was a hand made car when an error of up to 10 m.m. was found in the position of most of the bolt holes, except those for important bolts, such as those locating the rear axle.

The job was not hurried this time and the whole car was thoroughly checked over. The factor of safety built into some of these old cars seemed greater than that applied to the axles etc. of more modern vehicles, these older components often being much more substantial. Those on the Bugatti, already of a considerable age, seemed to cope with the extra weight and over twice the horsepower fairly well. However one rear axle did break on the high adhesion concrete track at Ohakea which would have caused a high level of stress.

Ron had converted the brakes to hydraulic operation and we had the drums hot dip galvanised to improve their appearance, although from a cooling point of view rusty steel may have radiated heat better. Not that there was much room for more rust, as the drums were very thin and flexible, but even so seemed to provide some reliable stopping power. Ron told me that in the later races, when he was braking for a corner, McLaren and others in their lightweight disc braked Coopers, would come rushing past, slow quickly and then round the corner. There was nothing he could do about it, such was progress.

We wanted to retain the traditional Bugatti appearance and I did my best to compare a Jaguar radiator with the type 38. Using a graph from Automobile Engines by Judge, it seemed possible that the type 38 radiator could just do the job at over 65 m.p.h., provided the efficiency of the different core types were equal. I had no means of verifying this but took a risk and fitted it. After a short race, a couple of hillclimbs and 23 laps at Ohakea, the cooling was proven to be inadequate.

Ron then fitted a Jaguar radiator as a trial. Second place in the North Island Beach Championship was followed by a real endurance driving test. The car was driven to Dunedin, subsequently winning the N.Z. Championship Road Race and then driven home again.

After this experience proving the cooling requirements, Ron was able to adapt a Whippet radiator fitted with a new core, to the Bugatti bonnet, so that the car once again looked very much as it should.

The engine was now improved by fitting a C-type head and D-type nine to one pistons, bringing the b.h.p. up to about 230. Close ratio gears were also fitted to the gearbox.

The Bugatti Jaguar with temporary Jaguar radiator, as was fitted when the car won the 1954 Championship Road Race.
Ron is adjusting brakes.

The 1956 season began with a long 210 mile race, the N.Z.I.G.P. at Ardmore, where Ron finished sixth and first N.Z. driver. There followed a fairly successful South Island tour, but there was concern regarding a cracked steering box, which was clamped together to last until a new casting could be made during the winter.

Reg. Parnell, after following Ron on the bumpy round the houses circuit at Dunedin, commented that he had never seen a Bugatti perform so many antics, so I guess the Jaguar power must have made the rear end very skittery.

Ron told me that during the Invercargill, Ryal Bush event, the car reached 155 m.p.h. down the long straight. This was rather surprising, as the C-type Jaguar, is a relatively long stroke engine.

Personally, I had no desire to drive the car, being unable to fit my long legs into the cockpit comfortably. Furthermore I once had a short and painful ride as passenger at slow speed on a bumpy road, when the whole car seemed to consist of unsprung weight. However, Ron reported that at higher speeds on reasonable roads it rode much differently, which could well have been the case. Warren Parkinson, a great supporter of Ron, when allowed to drive the Bugatti out to Glen Murray one day, managed to fit his long frame into the cockpit and became so enraptured with the performance that he eventually found himself miles away from his destination. It turned out that he had taken a wrong turning thus causing some consternation among those of us who were following, but had arrived first.

The car went on to give Ron a lot more competitive motoring the following season, with little trouble, after which it was retired from racing. The Jaguar engine was taken out and fitted into a Special with more modern suspension.

One memory I will always retain is the sensation of being passed around the curve by the hangars when racing the BSA at Ohakea, and seeing black rubber dust streaming off the rear tyres of the fast disappearing Bugatti.

On the Limit. (From a tiny 20X30 m.m. contact proof, courtesy Terry Roycroft.)


06/01/54 Ardmore Handicap 20 miles. Placed fourth.

16/01/54 Northern Sports Car Club Nth Island Championship Hillclimb, Wairamarama. Placed third, time 56 secs.

27/02/54 Hillclimb, Houghton Bay. Placed third.

06/03/54 Ohakea Trophy Race, completed only 23 laps.

Note : - At this point a Jaguar radiator was fitted to the car.

03/04/54 Nth Island Championship Beach Race, Muriwai 75 miles. Placed second to Palmer. George Smith, GeeCeeEss Special, retired.

19/04/54 N.Z. Championship Road Race Dunedin, 75 miles. Placed first. Time 84 mins 19 secs

Note : - At this point a new specially adapted radiator was fitted.

19/09/54 N.S.C.C. Hillclimb Wairamarama. Fastest time of the day. Time, 55.8 secs. George Smith, GeeCeeEss Special, 56.9 secs.

26/09/54 Auckland Car Club Hillclimb, Muriwai. Fastest time of the day. Time 38.7 secs.

09/10/54 N.S.C.C. Beach Race, Muriwai, 10 miles. Placed second to George Smith. Handicap Race, 10 miles. Placed second.

11/12/54 Auckland Car Club Quarter Mile Sprint. Standing, Time,15.9 secs and fastest time of the day. Flying, Time 9.3 secs and fastest time of the day.

15/01/55 N.Z. Championship Hillclimb, Wairamarama. Placed second. Time 55.7 secs.

19/02/55 N.Z. Championship Beach Race, Oneti. 40 miles. Placed second to George Smith.

04/03/55 Hillclimb, Hora Hora.

27/03/55 N.S.C.C. Quarter Mile Sprint. Standing, Time,15.3 secs and second to George Smith, 14 secs. Flying 11.2 secs and second to G. Smith 9.9 secs.

16/04/55 Nth. Island Championship Hillclimb, Muriwai. Fastest time of the day, Time 37.2 secs.

Note : - At this time the engine was converted to Jaguar C-type specifications.

07/01/56 N.Z.I.G.P. Ardmore, 210 miles. Placed sixth and first N.Z. driver. Best lap time 1 min. 37 secs.

12/01/56 Levin Race Meeting. Retired due to broken steering box.

22/01/56 Wigram Trophy Race, 150 miles. Placed seventh and third N.Z. driver.

28/01/56 N.Z. Championship Road Race, Dunedin. Retired (steering box).

Bugatti Jaguar. Dunedin Road Race. 1956

11/02/56 Ryal Bush Invercargill, 150 miles. Placed fourth.

18/02/56 N.Z. Beach Championship, Oneti, 40 miles. Placed second to George Smith.

03/03/56 Ohakea Trophy Race, 30 miles. Placed second to Tom Clark (Maserati).

10/03/56 N.Z. Championship Hillclimb. Houghton Bay. Placed first in class.

17/03/56 Nth. Island Championship Hillclimb, Hora Hora. First in class and third fastest time of the day.

08/9/56 Quarter Mile Sprint, Matamata. Standing, 15.2 secs and fastest time of the day. Flying, 6.8 secs and fastest time of the day, Time 37.2 secs, 134.3 m.p.h.

22/10/56 Levin Races. Placed third in two races each of 10 laps.

---1956 N.S.C.C. Hillclimb. Practice time 46.5 secs. Retired after leaving the road.

12/01/57 N.Z.I.G.P. Ardmore, 250 miles. Driver P. Gendall, Placed eleventh.

09/03/57 N.Z. Hillclimb Championship, Hora Hora. First in class, time 1 min 7 secs and second fastest time of the day

16/03/57 Nth. Island Hillclimb Championship Hawera. Second in class and fourth fastest of the day.

23/03/57 N.Z. Beach Racing Championship, Oneti, 40 miles. Placed first.

30/03/57 Levin Races.

06/04/57 Taumarunui Quarter Mile Standing Sprint. Time 14.5 secs and second to the Lycoming Special, 13.5 secs.

07/04/57 Taumarunui Hillclimb. Fastest time of the day.

13/04/57 Auckland Car Club Hillclimb, Muriwai. Fastest time of the day. Time, 37.5 secs

---1957 Waipu Gorge Time Trial. Fastest time of the day, Time 1 min 13 secs.

03/06/57 Southbridge 100 Mile Road Race. Retired with broken valve when in third place.

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