All 1965 F1 Engines
GRAND PRIX RACING is an astonishing something or other - although we're not sure whether that something should be called a sport, a business or a technical exercise. Four past seasons, with unsupercharged gasoline-burning engines restricted to a ridiculously small 1.5-liter maximum displacement, have somehow or other produced record-breaking speeds as well as fierce intermarque rivalry. Now that a return to more adequately dimensioned 3-liter Grand Prix engines in 1966 is just over the horizon, and sports/ racing cars with engines in the 4- to 7-liter size range are becoming popular, Grand Prix racing ought to be facing a dull season. Instead, however, we are waiting with bated breath to see exciting new engines in action.

Success in the world championships has not been anyone's monopoly during the 1961-65 Formula. Ferrari built the championship mount for Phil Hill in 196 I, getting a 120° V-6 engine going well before rival V-8 units were ready. The 1962 championship went to Graham Hill with the V-8 BRM, 1963 was the year of Jim Clark with the Lotus built around a Coventry Climax V-8 engine, and in 1964 Ferrari triumphed again with John Surtees driving V-8 cars instead of the anticipated flat-12 models which matured too slowly. During 1965, we should see (and hear) a very few flat-16 engines in action at the Grands Prix, as the development of Ferrari and Honda 12-cyl engines has tempted or frightened Coventry Climax into going four better.

Other things being equal, it is power which wins motor races, and in present-day Grand Prix racing other things do not remain unequal for long. Any worthwhile innovation in chassis or suspension design which one race car builder introduces is usually very visible, and so it can quickly be copied by rival factories, whereas it may take rather longer to find out why a rival has more power and to apply that knowledge to your own engines.

When racing cars have to be built to an engine disp]acement limit, the primary objective of every designer must be to lift engine speed as high as possible, this being the way to get more power per liter. Almost since the day James Watt first invented the horsepower, generations of engineering students have been brought up to remember just one simple formula:

PXLXAXN

                               Horsepower =                    33,000

Multiply together the mean working pressure P in the cylinders, the length of piston stroke L, the total piston crown area A, and the number of working cycles per minute N: then divide by the number which James Watt first thought of, and you have your horsepower.

Barring atom-splitting, that formula is fundamental. L multiplied by A is engine displacement, limited by racing rules. P is a pressure which for unsupercharged engines is pretty much limited by the energy which can be got by burning gasoline in atmospheric air. N is the important variable, and the bigger you can make it without the engine disintegrating the more power you can expect.

To get more revs, you need more little pistons moving through shorter distances. Keeping a constant displacement and stroke/bore ratio, if you have twice as many cylinders their linear dimensions are about 21 % smaller and you can run at 26% higher rpm for equal stresses: that 26% is the maximum amount of extra power you can hope to get when clutch on one end of the crankshaft. Honda does this on its V- I 2 engine, and so does Coventry Climax on its flat- I 6, and it is a technique which again halves the length of crankshaft that can vibrate torsionally. Driving the camshafts also by gear trains at the center of the engine reduces the possibility for timing to get far away from designed figures.

In the context of the 1964 Honda GP car layout, with a transverse engine just ahead of driven rear wheels, a central power offtake from the crankshaft can make for simplicity. One pair of gears can drive the clutch, and then an all-indirect gearbox with input and output at the same ends of two parallel shafts can take power to the final drive gearing. In any ratio, that layout has three successive stages of gearing, each absorbing small percentages of power, meaning that probably 10% to 15% of the engine's power never reaches the driving wheels.

Designing its 16-cyl engine for mounting fore-and-aft coupled to existing transmissions, Coventry Climax used a fairly long shaft to take power from a gearwheel below the center of an 8-throw crankshaft to a clutch at the extreme rear of the engine; this shaft was broken by torsional vibration early in the testing program, but the engineers reckon this to be a test-bed problem which will not recur with the engine in a car. Oil build-up in unwelcome places through churning by the various gears is, however, one reason why, at the moment of writing, this engine has still to show its designed power advantage over the V-8. If it is to show its intended 10% more power at the clutch, this gear-drive engine will probably need to have 15% more power than the direct-driving V-8 at its crankshaft.

While new 12- and 16-cylinder engines are still being developed for this last season of unsupercharged 1.5-liter Grand Prix racing, development of V-8 engines is by no means stagnant. To back up the few new 16-cyl engines, Coventry Climax has been working on the existing V-8 to keep it fully competitive. From just over 200 bhp last season, the power has been raised to 210 bhp at 10,500 rpm, with good torque starting at 7000 rpm and the engine safe up to 1 1,000 rpm.

Four valves per cylinder have proved well worth while on the Coventry Climax V-8 engine. In particular, they produce much better torque than does a 2-valve layout for pulling away from 8000 rpm, and the lighter valves make it safe to equip the car with a higher numerical gear ratio, as the 2-valve engine was limited to 9750 rpm.

Whereas some engines with pushrods and rockers operating four valves per cylinder have had radially disposed clutch on one end of the crankshaft. Honda does this on its V- I 2 engine, and so does Coventry Climax on its flat- I 6, and it is a technique which again halves the length of crankshaft that can vibrate torsionally. Driving the camshafts also by gear trains at the center of the engine reduces the possibility for timing to get far away from designed figures.

In the context of the 1964 Honda GP car layout, with a transverse engine just ahead of driven rear wheels, a central power offtake from the crankshaft can make for simplicity. One pair of gears can drive the clutch, and then an all-indirect gearbox with input and output at the same ends of two parallel shafts can take power to the final drive gearing. In any ratio, that layout has three successive stages of gearing, each absorbing small percentages of power, meaning that probably 10% to 15% of the engine's power never reaches the driving wheels.

Designing its 16-cyl engine for mounting fore-and-aft coupled to existing transmissions, Coventry Climax used a fairly long shaft to take power from a gearwheel below the center of an 8-throw crankshaft to a clutch at the extreme rear of the engine; this shaft was broken by torsional vibra­tion early in the testing program, but the engineers reckon this to be a test-bed problem which will not recur with the engine in a car. Oil build-up in unwelcome places through churning by the various gears is, however, one reason why, at the moment of writing, this engine has still to show its designed power advantage over the V-8. If it is to show its intended 10% more power at the clutch, this gear-drive engine will probably need to have 15% more power than the direct-driving V-8 at its crankshaft.

While new 12- and 16-cylinder engines are still being developed for this last season of unsupercharged 1.5-liter Grand Prix racing, development of V-8 engines is by no means stagnant. To back up the few new 16-cyl engines, Coventry Climax has been working on the existing V-8 to keep it fully competitive. From just over 200 bhp last season, the power has been raised to 210 bhp at 10,500 rpm, with good torque starting at 7000 rpm and the engine safe up to 1 1,000 rpm.

Four valves per cylinder have proved well worth while on the Coventry Climax V-8 engine. In particular, they pro­duce much better torque than does a 2-valve layout for pull­ing away from 8000 rpm, and the lighter valves make it safe to equip the car with a higher numerical gear ratio, as the 2-valve engine was limited to 9750 rpm.

Whereas some engines with pushrods and rockers operating four valves per cylinder have had radially disposed valves, racing engines with direct valve actuation from overhead camshafts all seem to have pairs of inlet and exhaust valves set parallel to one another in pent-roof combustion chambers. Four valves allow room for the spark plug above the piston center instead of toward one side of the combustion chamber, and give rather more area for gas flow than would two valves in a similar cylinder head, but they have sometimes been found to give torque rather than power improvement. Possibly extra skin friction in the ports (two ports will have 41 % more wall surface than a single port, if total gas flow areas are made equal for both layouts) may account for this effect.

Sheer horror at the thought of ever getting and keeping a 64-valve engine in perfect tune no doubt prevented Coventry Climax from using four valves per cylinder on its 16-cyl engine! In the case of BRM, experiments with a 4-valve cylinder head on the V-8 were disappointing, in that torque below the peak of the power curve was improved at the expense of peak power. In reverting to 2 valves per cylinder, however, BRM moved the exhaust from outside the engine to a neater location between the banks of cylinders, and adopted inlet ports between the 2 camshafts on each cylinder head, pointing almost exactly straight at the pistons.

This inlet port arrangement, which is also used on the 4-camshaft Ford Indianapolis engines and on the V-12 Honda, has been tried before, worked well for years on BMW and Bristol engines, but has disappointed some other experimenters. Although the port can be pretty straight, there is almost inevitably a slight S-bend in it, and it has been suspected that this S-bend disturbs the smooth flow of gas more than does a sharper single curve. As Enzo Ferrari uses between-the-camshafts induction ports (with conventional outside-the-heads exhaust ports) on the V-8 engine which won John Sur tees the 1964 World Championship, it must be pos­sible to make this design work!

All the successful Grand Prix racing engines nowadays use fuel injection rather than carburetors, so there is no venturi to obstruct gas flow or to complicate "organ pipe" tuning of ramming inlet pipe lengths. Quite sophisticated injection systems are needed with engines which are compelled to run on gas, higher metering precision being needed than with alcohol fuel. Ferrari fits a Bosch pump akin to those used on diesel engines to inject fuel into the combustion chambers, whereas the two British engines have the Lucas injection system: this latter has an electrical pump giving about 50 psi pressure, and an engine-driven distributing/ metering unit which lets shots of fuel from this pump go through nylon tubes to nozzles in the inlet stacks. British and Italian engines alike now use plate throttles, which move sideways on rollers to give a completely unobstructed air passage at full throttle.

Whereas production V-8 engines usually have their 4 crankpins phased 90° apart for best balance, racing V-8 engines now almost invariably use a "single plane" crankshaft akin to that of a 4-cyl engine. Secondary unbalance matters little, whereas the possibility of designing an ideal extractor exhaust system without cross-over pipes matters a lot.

Internal details of the latest Grand Prix engines are all based on aluminum blocks accommodating wet cylinder liners. Valve operation is direct from 2 overhead camshafts per cylinder head, with piston or Hispano-Suiza tappets. Pistons are of the classic racing slipper pattern, with just a crown molded as closely as possible around the valves, a shallow ring belt, and 2 narrow thrust faces. Titanium, the aerospace industry's costly and hard-to-work metal of extreme strength-to-weight ratio, is gradually coming into use inside Grand Prix engines.

Transistorized ignition by Lucas is used on the BRM and Coventry Climax engines, triggered magnetically by a pickup past which magnets fixed onto the flywheel pass: variable timing has not been found necessary. Ferrari, who uses 2 spark plugs per cylinder, employs 4 contact breakers (in two Marelli distributor units) and 4 coils on his V -8 engine.

Where do we go from here? In 1966 the Grand Prix cars will still be required to burn gas, but can have unsupercharged 3-liter engines, or supercharged 1.5-liter engines, or gas turbines rated according to a rather complex new system. The people who five years ago were shouting that a change from a 2.5-liter to a l.5-liter formula would make racing too expensive are now shouting that the change from a 1.5-liter to a 3-liter formula will make racing too expensive, but other people are saving their breath and making plans.

Which type of engine eventually proves best under the 1966 Formula I could depend quite a lot upon how "Commercial Fuel" is eventually interpreted. The types of gas sold to motorists nowadays are extremely heat-sensitive in their anti-knock quality, and while they suit contemporary production automobiles, they would not be suitable for use in highly supercharged engines. Had alcohol fuel been allowed, a supercharged l.5-liter engine would certainly have been expected to beat an unsupercharged 3-liter: if military aviation fuel is allowed, the supercharged engine may yet be competitive: at the moment, however, designers are coming to the view that an unsupercharged 3-liter engine offers the prospect of more power and longer range on a tank of gas.

One trick which might help the supercharged engine would be to meter water from separate tanks into the fuel/ air mixture entering the engine, as an internal coolant and anti­knock additive. Provided neither alcohol, anti-freeze, nor anything else inflammable was mixed with the water, it could hardly be counted as a fuel, and water injection can permit a useful increase in the supercharger pressure usable without an engine detonating itself to pieces. Doing this would, of course, mean carrying more weight in the car.

Gas turbine cars are another possibility, and a good deal depends on whether any company sees commercial advantages in sponsoring the development of a gas turbine Grand Prix car. A formula for rating gas turbines in comparison with piston engines, based on the area of gas flow at the turbine inlet nozzles and the attainable output pressures with various designs of compressor, has now been laid down by the FIA on the basis of proposals by BRM and Rover engineers. These latter gentlemen seem perhaps to have been rather too honest in admitting what their gas turbines can do, for the new type of engine to get a very favorable rating. I am sure a fast and responsive turbine-engined Grand Prix car could be built, if silence and fuel economy were sacrificed by governing the gas generator to run always at full speed, and opening a "waste gate" to by-pass the power turbine when thrust was not wanted.

At this moment, it would seem pretty certain that BRM, Ferrari, and Honda will be racing from the start of the new Formula I in 1966. Coventry Climax seems determined to take a rest from racing engine construction, perhaps because parent company Jaguar needs work on a new production engine hustled forward, so Lotus will probably have engines bought from BRM if Ford does not produce them something; and Cooper, who has just found fresh financial backing, may be having engines built by Maserati.

To make use of doubled power, a lot of thought is being given to the attractions of 4-wheel-drive, which by giving improved acceleration from slow turns and faster cornering may justify the extra weight and frontal area which its use involves. That, however, is another story!

The 1965 season, though the last, promises even further development of the 1.5-liter engine.