On the differences:
On the vibrations:Although the V8 with the now compulsory cylinder angle of 90 degrees may look like a sawn-off V10, technically it is an entirely separate concept with its own specific requirements. The V8 has a distinct firing sequence and demands a fundamentally different crankshaft design. Whereas a 72-degree offset crankshaft was used in BMW's V10 Formula One engine, V8 powerplants can feature crankshafts with either four throws spaced at 90 degrees or four throws spaced at 180 degrees. Standard production engines are fitted with 90-degree crankshaft variants due to their better dynamic attributes, but a 180-degree crankshaft is favoured in racing car engine design. The improved performance this allows offsets the disadvantages in terms of dynamics
And the article provides a good summary of the new restrictions placed on the V8 engines of 2006:The V10 entered a critical area in terms of vibrations between 12,000 rpm and 14,000 rpm. However, this was not an issue as the engine did not spend much time in this rev band and smoothed itself out again once the driver stepped up the revs. And, since that was where it spent the majority of its time, vibrations were not a worry. A V8, on the other hand, is not so well off. Its vibration curve enters critical territory later than the V10 ? from approximately 16,000 rpm ? and continues to climb from there. It is therefore no longer possible to think in terms of getting through a difficult patch and everything will be all right. Now, the problem of constantly increasing vibrations has to be confronted head on. If you don't get a handle on vibrations, they will eat into the service life of the engine and multiply the loads exerted on chassis components
The article also has a timeline of the V8 engine, a comparison table between the V10 and V8 and some interesting numbers such as "8 million ignitions per race" and "A piston accelerates from 0 to 100 km/h in 0.3 thousandths of a second "The regulations have sensibly nipped any natural tendency among the teams to reach straight for exotic ? and expensive ? ultra-light materials in the bud. The engineers work with conventional titanium and aluminium alloys, as stipulated in the regulations. The new V8 has to be heavier than its predecessor, even though the 2005 engine had two extra cylinders. This season's powerplants must tip the scales at no less than 95 kilograms. This should include the intake system up to and including the air filter, fuel rail and injectors, ignition coils, sensors and wiring, alternator, coolant pumps and oil pumps. It does not include liquids, exhaust manifolds, heat protection shields, oil tanks, accumulators, heat exchangers and the hydraulic pump.
Added to which, the new regulations stipulate that the engine's centre of gravity must be at least 165 millimetres above the lower edge of the oil sump.
Previously a closely guarded secret, the dimensions of the cylinder bore are now limited to a maximum 98 millimetres. The gap between the cylinders is also set out in the rulebook ? at 106.5 millimetres (+/- 0.2 mm). The central axis of the crankshaft must not lie any less than 58 millimetres above the reference plane
Another critical change in the regulations is the ban on variable intake systems. Known as "trumpets", these systems could previously be used to optimise the car?s torque curve. The fixed duct lengths will now make achieving good engine driveability a more exacting challenge. The teams will have to strike a compromise between maximum power and good driveability. Where the best compromise for the pipe lengths is to be found depends on various factors. The track layout and the weather, for example, both play a role.
Joining variable intake systems on the black list are variable exhaust systems and variable valve control systems. The power supply to the engine electrics and electronics is limited to a maximum 17 volts and the fuel pump now has to be mechanically operated. Only an actuator may now be used to activate the throttle valve system. With the exception of the electric auxiliary pumps in the petrol tank, all sub-components must now be driven mechanically and directly via the engine
The full article is available here
Click here for the 2006 F1 Regulations
