The Canadian-American Challenge Cup series moved beyond the halfway mark with the sixth of the 11 scheduled races at the very attractive 4-mile Road America course, set amid the rolling farmlands of central Wisconsin. The field of 38 cars was the largest to turn out for a Can-Am this year but there were only three significant changes from the previous race at Mid-Ohio. Mark Donohue’s Lola T163, which only raced for the first time at Mid-Ohio, was withdrawn from the remainder of the series by car owner Roger Penske because the team’s other extensive commitments (particularly in Trans-Am saloon racing) didn’t leave enough time to make the Lola competitive. Donohue’s absence, however, was more than offset by the entry of Mario Andretti in the first really competitive Ford-powered car to appear this year. The car itself is a McLaren M6B (fitted with M12 suspension) but the massive 8-litre, all-aluminium Ford engine has been developed by Ford stock car experts Holman & Moody from Ford’s new 7-litre stock car powerplant. The engine develops in the region of 720 h.p. at 6,500 r.p.m. (with as much as 625 ft. lb. of torque) and Andretti, who said he could spin the wheels in almost any gear, was just the man to make the most of it. Also new to the series was a car sponsored by the Armco Steel Corp. to demonstrate the potential of various forms of stainless steel. The monocoque chassis was designed and built by Bob McKee. The 7.5-litre Oldsmobile engine, fitted with twin turbochargers operating at a boost of 10 p.s.i., is reversed 180 degrees in the chassis and drives all four wheels via a 2-speed automatic transmission (developed from Oldsmobile’s Turbo-Hydramatic), a Ferguson torque-splitting centre differential, and front and rear differentials designed by McKee. The torque is a whopping 700 ft. lb. at 4,100 r.p.m. and the power over 700 h.p. at 6,100 r.p.m. Unfortunately the car was troubled by teething problems with both the brakes and the automatic transmission, and it was withdrawn after U.S.A.C. driver Joe Leonard had qualified it 24th fastest.
Denis Hulme and Bruce McLaren again dominated qualifying in the works McLaren M8Bs (though without their usual intra-team rivalry) as Hulme securely wrapped up the pole with a lap of 2 min. 06.3 min. (114.014 m.p.h.) that was 3.5 seconds under McLaren’s 1968 qualifying record. McLaren was 1.1. seconds behind at 2 min. 7.4 sec. and Andretti showed the great potential of his Ford-powered car by qualifying third fastest at 2 min. 8.4 sec.—the closest anyone has come to the McLarens all season. But there was a large gap to Peter Revson (Lola T163) at 2 min. 12.1 sec., Chuck Parsons (Lola T163), George Eaton (McLaren M12), Chris Amon (6.2-litre Ferrari) and Jo Siffert (4.5-litre Porsche 917PA).
Despite Andretti’s times, however, the race was a complete débacle as five of the first 10 qualifiers retired before the 50-lap, 200-mile event was 10 laps old. Andretti suffered a broken suspension upright in a final warm-up session and, although it was changed, he didn’t even reach the start line before retiring with a broken driveshaft universal joint. On the third lap George Folmer’s Ford G7A was out with the transmission mainshaft broken; on the fourth lap a punctured tyre knocked out Surtees’ Chaparral 2H; on the seventh lap Siffert missed a shift in the Porsche and the engine came apart; and on the eighth lap Eaton parked his McLaren M12 with all the gauges up against the pegs. The remainder of the race could hardly be anything but an anti-climax. McLaren and Hulme played cat and mouse with Amon for 100 miles before pulling away to take the chequered flat one-tenth of a second apart, McLaren leading. Amon held down a secure third until running out of fuel with six laps to go, which gave the Lola T163s of Parsons and Revson third and fourth places, one lap down. Tony Dean’s 3-litre Porsche took a well-deserved fifth place, three laps down, and he was followed home by Motschenbacher’s McLaren M12.
Bridgehampton Grand Prix
The seventh round of the Can-Am series was held at the Bridgehampton circuit on Long Island, which is not unlike Zandvoort in its setting in the sand dunes overlooking the sea. In contrast to Elkhart Lake, the field of 20 cars was the second smallest of the year—Mario Andretti, Joe Leonard and Dan Gurney all taking part in a clashing U.S.A.C. Championship race. The only interesting newcomer to the series to appear at Bridgehampton was Pedro Rodriguez in the same 3-litre Ferrari 312 coupé prototype that he drove at Le Mans. Among the regular, John Surtees reverted to Jim Hall’s McLaren M12 (which he drove in the first three races), the disappointing Chaparral 2H being kept in Texas for further development. Chris Amon’s Ferrari 612 was fitted with larger fuel tanks (to eliminate the costly failure at Elkhart Lake), while Denis Hulme’s works McLaren M8B was using a new camshaft intended to give more power at the top end of the r.p.m. range. In addition, both works McLarens and Jo Siffert’s Porsche 917PA were using new Goodyear tyres whose internal construction was developed from that used by Goodyear in Formula One. These tyres expand noticeably at speed and have a slight tendency to “creep” around the wheel, but they do provide a lot more grip and the breakaway is much more progressive.
The battle for starting positions was one of the best of the series—but it didn’t involve the McLaren team. McLaren and Hulme sewed up the front row during the first session with times of 1 min. 24.62 sec. and 1 min. 24.94 sec., respectively (compared with McLaren’s 1968 lap record of 1 min. 28.88 sec.), and were so confident that their time would not be beaten that they skipped the first qualifying session entirely to go water skiing! (The mechanics, however, spent the next 12 hours stripping the engines and going over both cars with a fine comb—and it is that sort of meticulous preparation that has put the McLaren team where it is.) Meanwhile, Surtees and Amon fought a 2½-hour duel for the third qualifying spot, the verdict going to Amon by 0.2 seconds—1 min. 26.31 sec. against Surtees’s 1 min. 26.53 sec. Peter Revson (Lola T163) was next at 1 min. 28.69 sec., followed by George Eaton (McLaren M12) at 1 min. 28.85 sec. Siffert (Porsche 917PA) at 1 min. 29.19 sec., Chuck Parsons (Lola T163) at 1 in. 29.24 sec., and Lothar Motschenbacher (McLaren M12) at 1 min 29.98 sec.
Hulme and McLaren jumped into considerable lead right at the start of the 70-lap, 200-mile race, with Surtees third and Amon fourth, but Amon’s misfortune struck within three laps this time when the oil pump drive failed. The pattern of the race was established almost immediately and remained unchanged fro most of the first half, with Hulme and McLaren running as they pleased in front. Surtees was 12 seconds behind in third, Eaton another seven seconds back in fourth and Siffert, despite giving away 2.5 litres to the 7-litre cars in front of him, only seven seconds behind Eaton. Motschenbacher, his locking differential not locking, was one lap back in sixth and behind him Rodriguez and Dean were having a tremendous scrap in the 3-litre Ferrari and Porsche respectively. Parson was recovering from four pit stops to replace bodywork damaged by a course marker that had been thrown out on the track. Soon after the halfway mark Eaton’s throttle began to stick and on the 44th lap he had to give way to a relentless Siffert. A dozen laps later Siffert advanced to third when Surtees’ overheating engine began to expire—and within three more laps both Eaton and Surtees retired with blown engines. The works McLarens then cruised home, Hulme taking the chequered flag by a car length over McLaren with Siffert bringing the Porsche into a well earned third place 61 second behind (and the only other car on the same lap as the leaders). Motschenbacher was fourth, three laps down; Rodriguez just held on to fifth from Dean after making a last-minute fuel stop; and Parsons climbed back from 15th to finish seventh. The Can-Am standings after seven of the 11 races are Hulme 110 points, McLaren 105, Parsons 44, Amon 39, Eaton 32, Surtees 30 and Stiffert 28.