(This article gets technical at times. I want to write something that as many people as possible find helpful so if it stuff you already know, apologies if it seems patronising. Just in case anyone is unaware of the basics of the four-stroke combustion engine, have a look at this.)
It is emerging news that from 2013, Formula One engines are likely to be 1·5 litre turbo-charged engines, with fuel injection and KERS. Before I wrote about this, I decided to go over the history of Formula One engine rules which turned into a separate blog.
The Formula One World Championship started in 1950 with a maximum of 4·5 litre engines or 1·5 litre if supercharged. (In an engine, the capacity is the total volume of displacement of all the cylinders, so, for example, if one cylinder moving from it’s top position to bottom position increases the volume of the chamber by half-a-litre and the engine has six such cylinders, then it’s capacity is 6 x 0·5 = 3 litres.)
Supercharging involved a device powered off the engine that pre-compresses the air before it enters the cylinders of the engine. Of course, the air/fuel mixture will be further compressed within the cylinder before ignition. The more fuel the engine can explode in each combustion, the more power it can provide, but only as much fuel can be ignited as oxygen present allows. Air is about 20% oxygen so the more air that can be forced in by the supercharger, the more fuel can be mixed with it to provide more power. Power is taken off the engine to drive the compressor but supercharging makes the engine significantly more powerful without using a larger, heavier engine.
Alfa Romeo drivers, Giuseppe Farina and Juan Manuel Fangio won the first two titles with straight-8 supercharged engines providing over 400 hp. Due to the difficulty of putting together good fields of F1 cars in post-war austerity-stricken Europe, the World Championship was run to Formula Two rules in 1952 and 1953.
From 1954 to 1960, the rules allowed 2·5 litre engines. Also allowed were 0·75 supercharged engines but no one bothered. Engine power during this period was up to about 290 hp.
Then for 1961, engine capacity was reduced to 1·5 litres knocking engine power back to about 150 hp. This left F1 cars under-powered. Although engine power had increased by about 50% by 1965, and with other technological advances the cars became faster than with previous engine rules, sportscar racing had bigger engines, more speed and was becoming more popular.
Three-litre engines (or 1·5 supercharged engines) were allowed in 1966. It says much about how Formula One back then was a much more backwater sport that many top teams could not get suitable engines. In ’65, Jim Clark had won the title for Lotus powered by Climax V8s but the team went into ’66 with a bored-out two-litre version instead. BRM similarly increased their engines to two litres, Cooper had uncompetitive Maserati engines, Ferrari had a decent engine but the car was too heavy. Hence it was that Jack Brabham won the title in a Brabham-Repco (followed the season after by team-mate Denny Hulme) despite a rather agricultural engine built from a stock-block by an Australian spare-parts company.
For 1967, Ford paid Cosworth to build an F1 engine for Lotus. The engine was late but won on it’s debut at the Dutch Grand Prix. After Jim Clark’s death in 1968, team-mate Graham Hill won the F1 title. The Ford Cosworth DFV with numerous teams won 155 races (including clean sweeps in ’69 and ’73), powered twelve driver World Championships and Michele Alboreto took the V8’s last win in a Tyrrell at Detroit in 1983. During this time, it had been developed from about 400 to 500 bhp (no, I do not know the difference between horse-power and brake-horse-power either). Three driver titles in this period were won by Ferrari with a flat-12 engine.
Jean-Marie Balestre, Max Mosley’s predecessor when FIA was called FISA, had a reputation for being pro-French over F1 matters. This may be why Renault were able to enter Formula One in the second half of 1977 employing the loophole of the supercharger rule to race with a turbocharged 1·5 litre V6 engine.
Turbochargers are superchargers except instead of the compressor being powered directly off the engine, the mass-flow of exhaust gases drives a turbine that drives the compressor. This uses the energy of exhaust emissions, that would otherwise be wasted, so gaining the advantage of pre-compressed air to make the engine much more powerful without taking some of that power from the engine to achieve it.
Obviously, history shows that turbos were the future but Renault masked this by struggling to build a good team or cars, and suffering myriad engine and turbo failures. By ’79 they won their first race, the French GP at Dijon, with Jean-Pierre Jabouille first, and the famous late-race battle for second between his team-mate, Rene Arnoux, and Gilles Villeneuve’s Ferrari. In the early ‘eighties, they were fast, could turn up the turbo-boost for qualification, and won races but often led until breaking down. Ferrari quickly won races with their new V6 turbo in 1981 and only lost the drivers’ title in ’82 after Villeneuve’s horrific death and Didier Pironi’s leg-smashing Hockenheim crash. In 1983, it was Nelson Piquet in a Brabham powered by a BMW turbo engine that beat Renault’s Alain Prost to the first turbo title by two points.
By then, all the teams had turbo engines, or were very keen to get a deal, with turbos winning exclusively 1984 to 1988, titles going to McLaren-TAG Porsche (made by Porsche, paid for by TAG), Williams-Honda and McLaren-Honda drivers. Fuel limits on race-fuel were introduced to curb speeds (although not in qualification) with fuel-strategy for the turbo-teams becoming an important element. The limit was 220 litres in ’84 and ’85, down to 195 the following two years. In 1986, only 1·5 litre turbo-engines were allowed with Tyrrell and Minardi during ’85 being the last of the field to go turbo.
By the end of ’86, the top turbo engines were giving around 900 bhp in races and perhaps as much as 1500 bhp in qualification (I once read that one manufacturer did not know what power they had in qualification as their dynamometer only went up to 1000 bhp). Drivers had knobs to adjust the turbo-boost but would not run at maximum for the race distance as not only would fuel run out but the engine would have blown up. A turn of boost could be used for starts or overtaking. Martin Brundle described the phenomenal acceleration available in qualification as, “the horizon moved towards you”.
In 1987 and 1988, FIA moved to phase out turbos, limiting boost to 4 bars and allowing normally aspirated engines of 3·5 litres. For the first year, separate points championships were created for non-turbo entrants with Jonathan Palmer (Tyrrell-Ford) winning The Jim Clark Trophy and Tyrrell winning The Colin Chapman Trophy. The extra titles were dropped in ’88. The fuel-limit was reduced to 155 litres, and turbo-boost limited to a measly 2·5 bar. Whilst turbos still ruled the roost, the playing field was much more level with normally aspirated results lead by Thiery Boutsen (Benetton-Ford) collecting five third places to finish fourth in the title-hunt, and Nigel Mansell getting two second places for Williams-Judd.
For 1989, turbos were banned and the 3·5 litre engines were adopted by all with power climbing to over 800 bhp by 1994. In 1995, displacement capacity was reduced to 3 litres. With development spending escalating this century pushed by manufacturers such as BMW, Mercedes, Honda and Toyota, engines of over 19,000 rpm were developed capable of over 900 bhp. All the engines were V10s with manufacturers and the sport keen to avoid the spending war of a possible step to V12s. In 2005, V10s were mandated with a maximum of five valves.
2006 not only saw 2·6 90° V8 engines introduced but a raft of rules covering maximum bore of cylinders, minimum weight of engines (to avoid spending on lighter exotic metal components), maximum of four valves per cylinder, and many other stipulations too numerous to list. STR used rev-limited Cosworth 3-litre V10s for one season as a transition compromise.
(Each cylinder only needs two valves to work, one to let the air and fuel in and one to let the exhaust gases out. However, having, for example, two inlet and two outlet valves would enable easier flow in and out, just as one breaths through one’s mouth as well as one’s nose when exercising. When Cosworth were squeezing the last bit of development out of the DFV in the ‘eighties, they created a short-stroke version (DFY) that had wider-bore cylinders that moved up and down by less (to maintain the displacement capacity) so wider valves could be used to increase engine performance.)
Engine power crept over the 700 bhp mark, and with manufacturers spending astronomical millions to keep up with each other, in 2007, development was frozen to 2006 spec with a 19,000 rpm limit reduced to 18,000 in 2009. Additionally, teams were restricted to one engine a race-weekend, then had to make them last two weekends, before currently being allowed eight engines per driver to last the season.
In 2009, kinetic energy recovery systems were allowed, but more about that next time. Also, more about the engine ‘freeze’ and that which this article was initially about, the possible new engine regulations.
More on superchargers and turbochargers, and much in this piece was gleamed from this Wikipedia article.