Although Porsches swept the board in the third round of the World Championship for Makes at Silverstone on May 15th, with thirteen of the German cars in the top fourteen places at the finish. the Kosset Six Hours proved a much better race than many had dared to expect. It is true that the lone factory Porsche 935/77 driven by Jochen Mass and Jacky Ickx dominated the first halt of the event, leading for most of the time and winning by a little over three miles after covering. 230 laps of the Silverstone Grand Prix circuit. But throughout the six hours, that single Martini Porsche, with its 650 b.h.p., 2.85-litre turbocharged flat-six engine, had been chased resolutely by the rival Porsche 935 entered by the Kremer brothers for John Fitzpatrick and Frenchman Bob Wollek. The Kremer car eventually finished second after taking the lead on two occasions during the final two hours.
In practice, Mass had qualified fastest with a best lap of 1 min. 25.91 sec., an average of 122.86 m.p.h.. but Wollek was only 0.37 sec. slower. Third and fourth on the 28-car grid were the two Porsche 935s entered by German industrialist Georg Loos for Tim Schenken/Derek Bell and Rolf Stommelen/Toine Hezemans. Mass grasped an immediate lead at the start, but Wollek and Stommelen battled mightily over second place until the Frenchman made his first refuelling stop after 32 laps. Schenken’s car was soon in trouble with sagging oil pressure, a tired borrowed engine having been fitted overnight, and it eventually retired in a spectacular engine failure after 66 laps. Stommelen was also in difficulties before his first scheduled stop, having hit an errant hare that damaged his Porsche’s bodywork, closed up a brake ‘cooling duct and caused its handling to deteriorate as well.
Mass and Ickx between them held the lead without interruption for over four hours, the works Porsche running perfectly apart from an unhealthy appetite for brake pads. But then a 3 1/2-minute pit stop for all four wheels and pads to be changed let the Kremer Porsche into the lead, and although Mass regained the initiative when that car next refuelled, he lost it again when he himself had to pit again. Mass took the lead for the final time on the 203rd lap, clinging to his advantage despite a heavy shower of rain in the final half hour that saw him bravely stay out on slicks until ordered in by the Porsche team manager for a change to wet weather tyres. Wollek and Fitzpatrick finished a hard-trying second, and Stommelen/Hezemans came third. Fourth overall and winner of the 2-litre class after a brilliant drive by Ronnie Peterson and a more than competent performance from his partner Helmut Kelleners was the BMW 320i run by the German FaItz team. In ninth place overall, Kurt Simonsen and Kenneth Leim captured the 3-litre class award with their Porsche Carrera RSR after a running battle throughout the six hours with the similar cars of Klaus Utz/Armin Jahn and Englishmen Mike Franey/Ian Bracey.— J.C.T.