The Sebring 12 Hours
(March 22nd)
Ferrari v Porsche–But Ford wins
Sebring is a tiny township in the centre of Florida, U.S.A. Despite the image conjured up by Palm Beach and Miami, most of Florida is drab, flat and largely semi-swampable. South of Sebring are hundreds of square miles of the Okaloacoochee Slough and the Big Cypress swamp containing areas reserved for the Seminole Indian Tribes.
Its hot sunny climate and big game fish explain the popularity of the Florida coast as a holiday area but the central parts are largely under developed. Sebring contains mostly motels and other facilities for the transient passing through to the southern coast, but once each year it comes to life when its ex-military airfield is the setting for the 12 Hours Sports Car Endurance Race.
There was a very strong entry for this, the 18th Sebring 12 hours race, counting as it does towards two World Championships, the Challenge Mondial de Vitesse et d’Endurance (first race of the series) and the International Manufacturers’ Championship (after Daytona—the second race of the series).
Numerically, Porsche had the most powerful team with five new prototypes on hand for Buzzetta/Stommelen, Ahrens/Herrmann, Mitter/Schutz, Elford/Attwood and Siffert/Redman, plus a spare. These were shortened “Spyder” versions of the 908, somewhat similar to the hill-climb cars. With minimal windscreen, as allowed under the new prototype rules, the car is only 28.8 in. high to the roll bar and weights 630 kg. (66 lb. less than the closed 908). The engine is basically identical but no longer has the “flat” configuration of crankshaft, the consequent new firing order giving smoother running. This was done in an effort to remove the cause of the cracked exhaust and alternator drives that eliminated the cars at Daytona. Additionally the intermediate idler shaft in the drive train which had to drive the re-positioned alternator at Daytona has been changed from alloy to steel for more strength.
Ferrari, making a welcome return to prototype racing, produced a new 3-litre car, the 312P (3-litre, twelve-cylinder). Based on the 612P Can-Am car and looking similar, the car has a tube and stressed panel chassis. The engine, derived from the F.1 3-litre project, is a 60º V12 with four valve heads and a compression ratio of 11.1. Power is quoted as 420 b.h.p. at 9,800 r.p.m on Lucas fuel injection. It uses Marelli “Dinoplex” electronic ignition circuitry with triggering in the distributor body. The weight of the car was quoted as 680 kg. The drivers were Amon and Andretti (who the Americans, in the nicest way—and with respect—call “Superwop”).
The Autodelta Alfa Romeo team had three new cars designated T33-3 although they bore only superficial resemblance to the 2-litre T33 of last year. The big cast tube chassis has been abandoned and the new car has an orthodox tube and sheet monocoque with large side boxes carrying foam-filled rubber fuel bags. The engine is a bored and stroked version of the 2-litre with dimensions of 86 x 64.4 mm., with four valves per cylinder. Like the Ferrari it has Lucas fuel injection and Marelli “Dinoplex” ignition. Power is quoted at 400 b.h.p. plus at 9,000 r.p.m. The car, as at Sebring, weighs 700kb., and efforts had been made to reduce this. One idea was to use glued radiators instead of soldered. The drivers for the three Alfas were to have been Surtees/de Adamich, Vaccarella/Bianchi and Casoni/Nanni Galli/Giunti, but Surtees decided that the cars were not competitive enough in practice and returned home. Casoni was then paired with de Adamich.
The Daytona-winning Sunoco Lola entered by Roger Penske for Buckman and Donohue had had its fuel injection replaced by carburetters. The 5-litre Traco-tuned Chevrolet engine was said to be producing 460 b.h.p. more reliably on carburetters. Bonnier shared Norunder’s Lola, and James Garner’s two American International Racing Lolas were entered for Patrick/Jordan and Motschenbacher/Leslie. These were fitted with new engines tuned by Art Oehrli but one of these broke in practice and a Traco engine was substituted.
The J.W.A. Team had the two Daytona GT40s for Ickx and Oliver and Hobbs/Hailwood. Ickx opted for the older car and had his special seat and wheel changed from the care he had damaged at Daytona when he hit the wall. This had been repaired for the other pair and both cars had previously partly blanked off cylinder heads unplugged to allow the cooling water to flow to the whole head and so avoid the local overheating which cracked the cylinders at Daytona. The Ickx/Oliver car had a new engine prepared by the A.A.R. outfit—now based in the States. This was supposed to be producing 460 b.h.p.
These nine prototypes and six sports cars were the strongest contenders for outright victory, but there was also an old 1961 much modified P1 Ferrari engineered by N.A.R.T. for Pedro Rodriguez and Parsons, and another N.A.R.T. car, a Dino, for Ricardo Rodriguez (no relation) and Kolb, plus Soler-Roig and Lins in a Porsche 907.
The rest of the field included several private Porsche 906s whose entrants were hoping that the works cars would have trouble, some 911s and a selection of the noisy 7-litre Trans-Am Corvettes running in the GT category.
British Leyland were running two M.G.-C GTs for Hopkirk/Hedges and Canadians Brack and Craig. They also had an M.G.-B GT for Truitt and Blackburn from Indianapolis. These cars were all to be sold and remain in the U.S. They even sold their practice car, a black M.G.-B to a team from Houston, Texas, whose Lotus 47 had broken its engine.
At Thursday’s practice Porsches set the pace with the Mitter/Schutz car’s time of 2 min. 42.7 sec. for the 5.2 mile circuit. This was well inside the lap record of 2 min. 48.6 sec. (110.03 m.p.h.) set up in 1967 by Spence in the 7-litre Chapparal. Siffert set up 2 min. 42.9 sec. (114.91 m.p.h.) for second fastest and the Motschenbacher/Leslie Lola was third at 2 min. 44.05 sec. Bonnier/Norinder recorded 2 min. 44.37 sec. and Attwood/Elford 2 min. 44.38 sec.
The J.W.A. GT40s were both around the 2 min. 48 sec. mark but were ahead of the new Alfas, which had chronic fuel injection pump bothers and overheating, not helped by the fact that the drivers were cutting the corners a little, forgetting the projecting radiators and hitting them on the tyre markers at the inside of the corners.
The Ferraris spent a good deal of time in the pits while the gear linkage was repeatedly aligned and tightened. It recorded 2 min. 44.4 sec., even allowing for difficult gear selection, and later at the evening practice improved this by a second.
On Friday, after more work on the linkage, Amon made a determined effort and took the pole position with a startling 2 min. 40.4 sec,. and Andretti showed that he would be no slower in the race by recording 2 min. 41 sec. The Sunoco Lola was timed at 2 min. 40.92 sec. for second spot, proving that it would be a major threat to the prototypes.
The Porsche times stood from the previous day at 2 min. 42.7 sec. and 2 min. 42.9 sec. respectively for the Mitter/Schutz and Siffert/Redman cars, and the two James Garner-entered Lolas were next with 2 min. 43.44 sec. for Patrick/Jordan and 2 min. 44.05 sec. for Motschenbacher/Leslie. Norinder and Bonnier were sixth fastest at 2 min. 44.37 sec., and the next Porsche was Elford/Attwood at 2 min. 44.38 sec., followed by Herrmann/Ahrens at 2 min. 44.51 sec. The fastest Alfa, that of Casoni/de Adamich with 2 min. 45.64 sec., was the only one in the fastest ten. The Buzzetta/Stommelen Porsche was 11th at 2 min. 45.67 sec., with the two J.W.A. GT40s 12th and 13th with 2 min. 47.43 sec. for Ickx/Oliver and 2 min. 47.74 sec. for Hobbs/Hailwood. The Vaccarella/Bianchi Alfa Romeo at 2 min. 47.95 sec. was 14th. All these cars had beaten the previous lap record, and the previous year’s fastest practice time set up by Siffert at 2 min. 49.42 sec.
The Race
At eleven on the Saturday morning, under the hot Florida sun, 70 drivers sprinted across the track Le Mans style and he race was on.
The Ferrari at the top end of the line momentarily refused to fire and it was Siffert who led the field away under the Mercedes bridge, followed by Mitter, Elford and Hermann, with Donohue’s Lola splitting the five Porsches ahead of Stommelen. The Ferrari was in seventh place. Siffert developed a lead of several seconds during the opening laps while his team-mates ran closely together behind. Giunti’s Alfa had shed a wheel passing the pits on lap 2, taking 44 minutes to get mobile again.
The Porsche trio led for the first hour, then Elford had an enforced pit stop of 40 min. while a damaged front wing was repaired. The Ferrari in fourth place looked as if it was in trouble and Amon indicated his intention of making a stop. Then he decided that the sticking gear-change gate could be cleared and he stopped out on the circuit and banged it into reverse. This removed the obstruction that was causing the gate to bang up, and he continued with no further trouble.
The Alfas had had a bitter disappointment earlier when their leading car, that of Casoni/de Adamich, was forced to retire with radiator breakage. This was obviously a fundamental defect and sure enough at 12.20 p.m. the other two cars were out of the race for the same reason. It looked as though the failure was caused by the heat attacking the glue.
Siffert led the race for the first 30 laps and had set up a new race record lap of 2 min. 44.6 sec. while in the lead. Elford’s enforced stop had put him out of the running, leaving Herrmann in second place ahead of the Ferrari.
The routine pit stops let the Lola through for 10 laps but by the 42nd lap Redman, having replaced Siffert, led the field, with Bucknum in the Lola second, ahead of Amon in the Ferrari. Redman held this lead till lap 58, nearly the three-hour mark, when he had an 8-min. stop to repair a steering link. This put the Lola in front again, followed by Ahrens and Mitter. These cars had all covered 64 laps while Buzzetta and Ickx had done 62 laps, with the Hobbs/Hailwood car one lap behind.
The Lola’s lead was short-lived and Amon overtook on the 64th lap. He held this lead for the next 21 laps but the Mitter/Schutz car was attacking, having overtaken Bucknum, caught Amon, and soon drew out a 10-sec. lead.
Just after 3.30 p.m., after about 500 miles’ racing, the Herrmann/Ahrens car, running fourth, came into the pits and was retired with a fracture of the chassis cross-member underneath the gearbox. At almost the same time the Donohue/Bucknum Lola retired from third place with the same suspension mount breakage that had retired the Bonnier/Norinder car.
This left the Ferrari and the Mitter/Schutz Porsche in battle for the lead three laps ahead of the rest of the field.
The Hobbs/Hailwood GT40 suffered a suspension ball-joint spindle breakage, necessitating a long pit stop. This later recurred out on the circuit and Hailwood could not get the car back to the pits.
By the halfway point, the order read Mitter/Schutz (Porsche) 128 laps; Amon/Andretti (Ferrari) 128 laps; Buzzetta/Stommelen (Porsche) 124 laps; Siffert/Redman (Porsche) 124 laps; Ickx/Oliver (GT4o) 123 laps; Motschenbacher/Leslie (Lola) 119 laps. The race average speed for the 128 laps covered by the leader was 110.45 m.p.h.—a new record.
The Ferrari and leading Porsche took turns to lead, dictated to some extent by their alternate pit-stop necessities. Schutz brought the car in briefly to have a bent suspension arm straightened. Soon after, Amon brought in the Ferrari with nose damage caused by running over parts of the Chevron, which had wrecked its rear end. Clearing out the broken pieces and repairing damage did not take long but it soon boiled once more due to air trapped in the cooking system after the rapid top-up during the pit stop.
The Siffert/Redman Porsche had retired earlier from fourth place, about the same time as the first Ferrari pit stop, with an identical chassis fracture to that which eliminated the Herrmann/Ahrens car.
Andretti was now using less revs. than usual in an effort to preserve the boiling engine, but was still forced to make frequent pit stops. On one of these there was a moment of drama when leaking fuel round the filler cap ignited and flames shot upwards. Alert marshals extinguished it instantly and the car then spent some time in the pits while mechanics attempted to force air out of the water system.
While Ferrari were desperately trying to keep their sole car in working order, Porsche were counting how many runners they had left and wondering when the next would crack up—literally. It happened at 7.30 p.m. when the leading car of Mitter/Schutz came into the pits with the same fracture as the others. It took frantic mechanics over half-an-hour to make a lash-up repair using steel bars bolted into place.
This put the car back to fifth place and left the fight for the lead between the ailing Ferrari and the Buzzetta/Stommelen Porsche. The Ickx/Oliver GT40 had risen to third place with the demise of the faster cars and was ahead of the Motschenbacher/Leslie Lola. In fifth place was the repaired Mitter/Schutz car, and Porsche 907 driven by Soler-Roig and Lins had risen to sixth.
Andretti was nursing the sick Ferrari but the GT40 was within striking distance and another pit stop for more flushing and replenishment let the GT40 into the lead with 1.5 hours to go. The Ferrari went off in pursuit but the GT40 had 20 minute in hand even after making its last routine stop. Ickx was sable to hold off the Ferrari until it was forced to make one more short stop, with only 15 minutes to go, which ended any chance it may have had of victory.
In the 12 hours of racing Ickx and Oliver completed 239 laps of the 5.2 mile circuit, a distance of 1,242.8 miles—their average speed, a new record, was 103.636 m.p.h.—L. A. M.